.NET Core: Windows Compatibility Pack

Windows Compatibility Pack

A little over a year ago Microsoft released the Windows Compatibility Pack for .NET Core that filled in some gaps in .NET Core APIs if your application doesn’t need to run cross-platform. While some of the APIs included in the compatibility pack was added back when support for .NET Standard 2 was released, such as System.Data.SQL client. Some of the APIs will never make it into the .NET Standard because they are Windows only constructs such as registry access.

Since it has been such a long time since the compatibility pack was released I thought this post would be a good reminder. In this post, we will create a new .NET Core application and using the Windows Compatibility Pack to access the registry.

Application Creation

Use the following command from a command prompt to create a new .NET Core console application.

dotnet new console

Use the following command to add a reference to the compatibility pack NuGet package.

dotnet add package Microsoft.Windows.Compatibility

Using the Registry

The following is the full code for the application. This code may not be the best practice, but it does demonstrate the usage of the registry.

class Program
{
    static void Main(string[] args)
    {
        var thing = "World";

        if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
        {
            using (var regKey = Registry
                                .CurrentUser
                                .CreateSubKey(@"Software\Testing\Test"))
            {
                thing = regKey.GetValue("ThingText")?.ToString() ?? thing;
                regKey.SetValue("ThingText", "Registry");
            }
        }

        Console.WriteLine($"Hello {thing}!");
    }
}

Take special note of the if statement surrounding the registry access as it allows you to check what platform you are running on and vary your implementation, which is very helpful if your application is actually run cross-platform, but you need some slight differences when running on a particular OS.

The application should output “Hellow World!” the first run and “Hello Registry!” the second run.

Wrapping Up

If you were creating a new application it would be best to stay away from platform specific API as much as possible and stick with the APIs defined by the .NET Standard. If you are trying to convert an existing application I could see the compatibility pack speeding your conversion without having to rewrite part of the application that happens to us Windows-based APIs.

GitHub and Azure Pipelines: Build Triggers

In response to my post on GitHub and Azure Pipelines, I got the following question on Reddit.

Does this automatically detect branches? From your screenshot, you’re building master. If you copy to feature-A, does a new pipeline automatically get created and built?

When I initially answered this question I didn’t go deep enough. The answer to does a new pipeline automatically get created and built is no as I replied, but I think the intent of the question is do I have to go set up a new pipeline every time I create a new branch and the answer to that is also no. The existing pipeline will be triggered when any change is checked in on any branch by default. Do note that it won’t be triggered when the branch is created only when a change is checked in.

Limiting Builds

There are a couple of ways to control what branches trigger continuous integration builds. The first is by making edits to the azure-pipeline.yml file in the repo and the second is via an override in the Azure Pipeline.

YAML

The official Build pipeline triggers docs are really good, but I will cover the basic here for including branches and excluding branches. Check for docs for information on path includes/excludes as well as how to control PR validation. As an example here is the yaml file used to define a build in this repo.

pool:
  vmImage: 'Ubuntu 16.04'

variables:
  buildConfiguration: 'Release'

steps:
- script: dotnet build Sqlite --configuration $(buildConfiguration)
  displayName: 'dotnet build $(buildConfiguration)'

In order to control what branches get built, we need to add a trigger section. The smilest example is to list the branches you want to build. Ending wildcards are allowed. See the following example (trigger section taken from the official docs).

pool:
  vmImage: 'Ubuntu 16.04'

variables:
  buildConfiguration: 'Release'

steps:
- script: dotnet build Sqlite --configuration $(buildConfiguration)
  displayName: 'dotnet build $(buildConfiguration)'

trigger:
- master
- releases/*

This would build master and all branches under releases, but nothing else. The following shows how to use includes and excludes together. Again the triggers section is taken from the official docs.

pool:
  vmImage: 'Ubuntu 16.04'

variables:
  buildConfiguration: 'Release'

steps:
- script: dotnet build Sqlite --configuration $(buildConfiguration)
  displayName: 'dotnet build $(buildConfiguration)'

trigger:
  branches:
    include:
    - master
    - releases/*
    exclude:
    - releases/old*

This would build master and everything in under releases that does not start with old. Really go read the official docs on this one to see all the ins and outs.

Azure Pipelines

To override the CI build from Azure DevOp go to the build in question and click Edit.

Next, select Triggers and Continuous integration and check Override YAML.

After checking the override you will see a lot more options light up. As you can see in the following screenshot the same include and exclude options are available with the same options for wildcards.

Wrapping Up

As you can see Azure Pipelines provides a lot of flex ability in how a build gets triggered. On top of what I covered here, there are also options for setting up scheduled builds as well as trigging a build with another build is completed. If you hit a scenario that couldn’t be covered I would love to hear about it in the comments.

GitHub and Azure Pipelines

A few weeks ago Microsoft announced that Visual Studio Team Services was being replaced/rebranded by a collection of services under the brand Azure DevOps. One of the services that make up Azure DevOps is Azure Pipelines which provides a platform for continuous integration and continuous delivery for a huge number of languages on Windows, Linux, and Mac.

As part of this change, Azure Pipelines is now available on the GitHub marketplace. In this post, I am going to pick one of my existing repos and see if I can get it building from GitHub using Azure Pipelines. I’m sure Microsoft or GitHub has documentation, but I’m attempting this without outside sources.

GitHub Marketplace

Make sure you have a GitHub account with a repo you want to build. For this post, I’m going to be using my ASP.NET Core Entity Framework repo. Now that you have the basic prep out of the way head over to the GitHub Marketplace and search for Azure Pipelines or click here.

Scroll to the bottom of the page to the Pricing and setup section. There is a paid option that is the default option. Click the Free option and then click Install it for free.

On the next page, you will get a summary of your order. Click the Complete order and begin installation button.

On the next page, you can select which repos to apply the installation to. For this post, I’m going to select a single repo. After making your choice on repos click the Install button.

Azure DevOps

After clicking install you will be thrown into the account authorization/creation process with Microsoft. After getting authorized you will get to the first set up in the setup process with Azure. You will need to select an organization and a project to continue. If you don’t have these setup yet there are options to create them.

After the process complete you will be land on the New pipeline creation process where you need to select the repo to use. Clicking the repo you want to use will move you to the next step.

The next step is a template selection. My sample is an ASP.NET Core application so I selected the ASP.NET Core template. Selecting a template will move you to the next step.

The next page will show you a yaml file based on the template you selected. Make any changes your project requires (my repo had two projects so I had to change the build to point to which project I wanted to build).

Next, you will be prompted to commit the yaml file to source control. Select your options and click Save and run.

After your configuration gets saved a build will be queued. If all goes well you will see your app being built. If everything works you will see something like this build results page.

Wrapping Up

GitHub and Microsoft have done a great job on this integration. I was surprised at how smooth the setup was. It was also neat to see a project that I created on Windows being built on Linux.

If you have a public repo on GitHub and need a way to build give Azure Pipelines a try.

Electron.NET: Save Dialog & File Writing

This post is another expansion of my Electron.NET sample to show how to prompt the user with a save dialog and write a file to disk. The sample code before any changes can be found here. As with all the posts I have done on Electron.NET the API Demos repo helped out a lot.

For this example, we will be adding an export button to the contact detail page that will export the contact as JSON.

Dialog Controller

Following how the API Demo is setup I added a DialogController with the following code.

public class DialogsController : Controller
{
    private static bool saveAdded;

    public IActionResult Index()
    {
        if (!HybridSupport.IsElectronActive || saveAdded) return Ok();

        Electron.IpcMain.On("save-dialog", async (args) =>
        {
            var mainWindow = Electron.WindowManager.BrowserWindows.First();
            var options = new SaveDialogOptions
            {
                Title = "Save contact as JSON",
                Filters = new FileFilter[]
                {
                    new FileFilter { Name = "JSON", 
                                     Extensions = new string[] {"json" } }
                }
            };

            var result = await 
                  Electron.Dialog.ShowSaveDialogAsync(mainWindow, options);
            Electron.IpcMain.Send(mainWindow, "save-dialog-reply", result);
        });

        saveAdded = true;

        return Ok();
    }
}

The setup above tells Electron when it receives a save-dialog request to show the operating system’s save dialog with the options specified. When the user completes the dialog interaction then it is set up so Electron will send out a save-dialog-reply message so anything listing can act on the user’s selection.

The bits with saveAdded is to work around an issue I was having with the dialog being shown multiple times. There is something off about my setup that I haven’t had time to track down, but I felt like even with this one querk this post is still valuable.

Next, I added the following import to the _Layout.cshtml file.

<link rel="import" href="Dialogs">

As I am writing this I am wondering if this could be the cause of my multiple dialog issues? Maybe this should just be on the contact detail page?

Contact Detail Page Changes

The rest of the changes are in the Views/Contacts/Details.cshtml. The first thing I did was add a new div and button at the bottom of the page. Based on the look of the existing page it isn’t the prettiest looking thing, but the look of the UI isn’t really the point of this post. Here is the code for the new div. Make note that the button has a specific ID.

<div>
    <button id="save-dialog" class="btn">Export</button>
</div>

Finally, the following script section was added.

<script>
    (function(){
        const { ipcRenderer } = require("electron");
        const fs = require('fs');
        var model = '@Html.Raw(Json.Serialize(@Model))';

        document.getElementById("save-dialog")
                .addEventListener("click", () => {
            ipcRenderer.send("save-dialog");
        });

        ipcRenderer.on("save-dialog-reply", (sender, path) => {
            if (!path) return;

            fs.writeFile(path, model, function (err) {
                console.log(err);
                return;
            });
        });
       
    }());
</script>

On the server side, the model is converted to JSON and stored which will be used when writing the file. If anyone has a better way of doing this part I would love to hear about it in the comments. I’m referring to this bit of code.

var model = '@Html.Raw(Json.Serialize(@Model))';

Next, a click event is added to the export button which when fired sends a message to show the save dialog defined in the controller.

document.getElementById("save-dialog")
        .addEventListener("click", () => {
                                     ipcRenderer.send("save-dialog");
                                   });

Finally, a callback is added for the message that the user has finished with the dialog that was shown.

ipcRenderer.on("save-dialog-reply", (sender, path) => {
    if (!path) return;

    fs.writeFile(path, model, function (err) {
        console.log(err);
        return;
    });
});

In the callback, if the user entered a path then the JSON for the model is written to the selected path.

Wrapping Up

While writing a contact to JSON might not be the most useful thing in the world the same idea could be used to with the information to a vCard file.

After working on this example I finally feel like I am getting a better hold on how Electron is working. Hopefully, this series is helping you feel the same. The completed code can be found here.

Electron.NET: Tray Icon

This post is a continuation of my exploration of Electron.NET which started with this post. Today I’m going to take the existing sample project and expand it to include a tray icon. As with the post on customizing the application level menus, this post relied heavily on the Electon.NET API Demos repo.

Add an Icon

The first step I took was to find an icon I wanted to show in the tray area. Since this is just a sample application I didn’t spend a lot of time on this. Once you have your icon it needs to be added to your project. Following the example, in the API Demo, I add an Assets directory to the top level of the project and copied in my Stock-Person.png file. This directory and file need to end up in the output of the builds which can be done by adding the following to the csproj file.

<ItemGroup>
  <None Update="Assets\Stock-Person.png">
    <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
  </None>
</ItemGroup>

In Visual Studio this can be done via the UI, but since I am sticking to VS Code for this project I did the edit manually.

Tray Controller

Add a TrayController to the Controllers directory which will be used to hold all the code needed to add the tray icon. The following is the full class.

public class TrayController : Controller
{
    public IActionResult Index()
    {
        if (!HybridSupport.IsElectronActive ||
            Electron.Tray.MenuItems.Count != 0)
        {
            return Ok();
        }

        var menu = new MenuItem[] {
            new MenuItem 
        { 
          Label = "Create Contact", 
          Click = () => Electron
                            .WindowManager
                        .BrowserWindows
                .First()
                .LoadURL($"http://localhost:{BridgeSettings.WebPort}/Contacts/Create")
        },
            new MenuItem 
        { 
          Label = "Remove", 
          Click = () => Electron.Tray.Destroy()
            }
        };

        Electron.Tray.Show("/Assets/Stock-Person.png", menu);
        Electron.Tray.SetToolTip("Contact Management");

        return Ok();
    }
}

Most of the code above is dealing with building an array of MenuItem which will be options when right-clicking the tray icon. In this case of this sample, there will be two menu items one for creating a contact and the other to remove the tray icon.

Electron.Tray.Show is the bit that actually shows the tray icon and it takes a path for the icon to display and the menu items to show. The last bit is a call to Electron.Tray.SetToolTip which, not surprisingly, sets the tooltip on the tray icon.

Include the tray icon

The final change is to make sure the code to show the tray icon gets run when the application starts. Open the _Layout.cshtml file in the Views/Shared directory. In the head tag add the following which will cause the application to call the Index action on the TrayController.

<link rel="import" href="Tray">

Wrapping Up

As with everything I have tried so far, Electon.NET makes it easy to add a tray icon to your applications. If you are a .NET developer so far I haven’t found any downsides to using Electron.NET. If you have hit any walls with this tool leave a comment. The finished code for this post can be found here.

Basic ASP.NET Core API Test with Postman

I had a reader email me about using Postman with ASP.NET Core API base on this post from a couple of years ago. Rather than working through that their specific issues are with that code, I thought it might be more helpful to write a post on creating a super basic ASP.NET Core API and use Postman to test it.

API Creation

We are going to use the .NET CLI to create and run API project so no Visual Studio or other IDE will be needed. The first step is to open a command prompt and navigate to (or create) the directory where you want the API project to live. Run the following command to create the API project.

dotnet new webapi

The webapi template creates a ValuesController with a Get action that returns an array with two values in it which we will be using as our test endpoint.

After the process finished we can now run the project using the following command.

dotnet run

After the run command, you should see something like the following.

Hosting environment: Production
Content root path: C:\YourProjectPath\ApiTest
Now listening on: http://localhost:5000
Application started. Press Ctrl+C to shut down.

The key bit in the above you need to look for is the Now listening on line as that is the URL we will need to use in Postman to test.

Testing with Postman

Postman is a great tool that to use when developing an API. It allows me to exercise all the functions of the API before any clients have been built. You can do some of the same things using a browser, but Postman was built for this type of usage and it shows. Postman is free and you can grab it here.

Run Postman and you will see something similar to the following screenshot.

For our simple test we want to do a Get request, which is the default, so all we need to do is past the URL from above into the address box and add in the route to the controller we are trying to test. For our sample to test the Get action on the ValuesController our URL ends up being http://localhost:5000/api/values.

Click the Send button and the results will show the lower area Postman (the large red box in the screenshot).

Wrapping Up

This is the simplest setup I could think of to get up and going with Postman and ASP.NET Core. Postman has so many more functions than I showed in this post so I hope this will be a good jumping off point for you all to learn more about this great tool.

Electron.NET: Custom Application Menus

This post will take the existing sample Electron.NET application used in Create a Desktop Application using ASP.NET Core and Electron.NET and Electron.NET with a Web API and expand it to customize the application menu. I leaned heavily on the Electron.NET API Demos repo to guide how this should be done. The code before any changes can be found here.

Menu Controller

While not a requirement I follow the API Demo example of putting the application level menus in its own controller. Add a MenusController to the Controllers directory. The following is the full class.

public class MenusController : Controller
{
    public IActionResult Index()
    {
        if (HybridSupport.IsElectronActive)
        {
            var menu = new MenuItem[] {
            new MenuItem { Label = "Edit", Submenu = new MenuItem[] {
                new MenuItem { Label = "Undo", Accelerator = "CmdOrCtrl+Z", Role = MenuRole.undo },
                new MenuItem { Label = "Redo", Accelerator = "Shift+CmdOrCtrl+Z", Role = MenuRole.redo },
                new MenuItem { Type = MenuType.separator },
                new MenuItem { Label = "Cut", Accelerator = "CmdOrCtrl+X", Role = MenuRole.cut },
                new MenuItem { Label = "Copy", Accelerator = "CmdOrCtrl+C", Role = MenuRole.copy },
                new MenuItem { Label = "Paste", Accelerator = "CmdOrCtrl+V", Role = MenuRole.paste },
                new MenuItem { Label = "Select All", Accelerator = "CmdOrCtrl+A", Role = MenuRole.selectall }
            }
            },
            new MenuItem { Label = "View", Submenu = new MenuItem[] {
                new MenuItem
                {
                    Label = "Reload",
                    Accelerator = "CmdOrCtrl+R",
                    Click = () =>
                    {
                        // on reload, start fresh and close any old
                        // open secondary windows
                        Electron.WindowManager.BrowserWindows.ToList().ForEach(browserWindow => {
                            if(browserWindow.Id != 1)
                            {
                                browserWindow.Close();
                            }
                            else
                            {
                                browserWindow.Reload();
                            }
                        });
                    }
                },
                new MenuItem
                {
                    Label = "Toggle Full Screen",
                    Accelerator = "CmdOrCtrl+F",
                    Click = async () =>
                    {
                        bool isFullScreen = await Electron.WindowManager.BrowserWindows.First().IsFullScreenAsync();
                        Electron.WindowManager.BrowserWindows.First().SetFullScreen(!isFullScreen);
                    }
                },
                new MenuItem
                {
                    Label = "Open Developer Tools",
                    Accelerator = "CmdOrCtrl+I",
                    Click = () => Electron.WindowManager.BrowserWindows.First().WebContents.OpenDevTools()
                },
                new MenuItem
                {
                    Type = MenuType.separator
                },
                new MenuItem
                {
                    Label = "App Menu Demo",
                    Click = async () => {
                        var options = new MessageBoxOptions("This demo is for the Menu section, showing how to create a clickable menu item in the application menu.");
                        options.Type = MessageBoxType.info;
                        options.Title = "Application Menu Demo";
                        await Electron.Dialog.ShowMessageBoxAsync(options);
                    }
                }
            }
            },
            new MenuItem { Label = "Window", Role = MenuRole.window, Submenu = new MenuItem[] {
                 new MenuItem { Label = "Minimize", Accelerator = "CmdOrCtrl+M", Role = MenuRole.minimize },
                 new MenuItem { Label = "Close", Accelerator = "CmdOrCtrl+W", Role = MenuRole.close }
                 }
            },
            new MenuItem { Label = "Contacts", Role = MenuRole.window, Submenu = new MenuItem[] {
                 new MenuItem { Label = "Create", 
                                Accelerator = "Shift+CmdOrCtrl+C",
                                Click = () => Electron.WindowManager.BrowserWindows.First().LoadURL($"http://localhost:{BridgeSettings.WebPort}/Contacts/Create")
                              }
                 }
            }
        };

            Electron.Menu.SetApplicationMenu(menu);
        }

        return Ok();
    }
}

What the above comes down to is building an array of MenuItem types and then using Electron.Menu.SetApplicationMenu(menu) to pass the array to Electron which handles replacing the default set of menus with the ones defined in the array.

For most of the items that were on the default set of menus all that is needed to add back the default functionality is to set the Role to the function you want. For example in the above for a Copy menu item, we can assign Role to MenuRole.copy and Electron will handle the implementation of a copy without us having to write any additional code.

Navigate to a page from the application menu

One thing I wanted to be able to do was from a menu create a new contact. It was easy enough to add a top-level menu for Contacts and a sub-item for Create. It took me a while, but I finally figured out how to build a URL that would work. The following code is the menu items for the Contacts menu.

new MenuItem { Label = "Contacts", Role = MenuRole.window, Submenu = new MenuItem[] {
     new MenuItem { Label = "Create", 
                    Accelerator = "Shift+CmdOrCtrl+C",
                    Click = () => Electron.WindowManager.BrowserWindows.First().LoadURL($"http://localhost:{BridgeSettings.WebPort}/Contacts/Create")
                  }
     }
}

The ASP.NET Core backend is running on localhost, the key that took me a while to locate was the port. In the end, I found that the port being used can be found using BridgeSettings.WebPort.

Include the menu

The final change that is needed is to make sure the new set of menus get rendered. For the sample application open the _Layout.cshtml file in the Views/Shared directory. Inside the head tag add the following line which will force a call to the MenusController when the application loads.

<link rel="import" href="menus">

Wrapping Up

Customizing the application menu ended up being pretty easy. If I hadn’t wanted to navigate to a specific page I would have been done in no time, but hitting the issue with navigation helped me learn more about how Electron.NET is working. You can check out the finished code here.

Electron.NET with a Web API

This post will be expanding on the introduction to Electron.NET that I did here to add in a Web API hit to pull some data as well as the UI on the Electron side to use this data. The code before any changes can be found here.

API Creation

To create the API I used the following from the command prompt in the folder where I wanted the new project to be created.

dotnet new webapi

API Data

Now that the API project is created we need to add in the ability to interact with a database with Entity Framework Core. Adding in Entity Framework Core ended up turning into a post of its own when you can read here.

The model and DB Context of the API project match what was in the blog post I linked above, but I am going to include them here. The following is the model.

public class Contact
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Address { get; set; }
    public string City { get; set; }
    public string Subregion { get; set; }
    public string PostalCode { get; set; }
    public string Phone { get; set; }
    public string Email { get; set; }
}

Next, is the DB Context, which is empty other than the DB Set for the contacts table.

public class ContactsDbContext : DbContext
{
    public DbSet<Contact> Contacts { get; set; }

    public ContactsDbContext(DbContextOptions<ContactsDbContext> options)
        : base(options)
    {

    }
}

With our model and context setup, we can run the following two commands to add the initial migration and apply the migration to the database.

dotnet ef migrations add Contacts
dotnet ef database update

API Endpoints

The API is just going to handle the basic CRUD (create, read, update, delete) operations for contact. Instead of hand coding the controller we are going to use some code generation provided by Microsoft. First, we need to add the Microsoft.VisualStudio.Web.CodeGeneration.Design NuGet package to the API project using the following command in a command prompt set to the root of the API project.

dotnet add package Microsoft.VisualStudio.Web.CodeGeneration.Design

Now with the above package installed, we can use the following command to generate a controller with the CRUD operations already implemented.

dotnet aspnet-codegenerator controller -name ContactsController --model Contact --dataContext ContactsDbContext -outDir Controllers -api

There is a lot of switches when using aspnet-codegenerator. The following is a rundown of the ones used above.

  • controller tells the code generator we are creating a controller
  • name defines the name of the resulting controller
  • model is the model class that will be used for the generation
  • dataContext is the DB Context that will be used for the generation
  • outDir is the directory the output will be in relative to the current directory of your command prompt
  • api tells the code generator this controller is for a REST style API and that no views should be generated

With the code generation complete the API should be good to go.

Electron Model

Over in the Electron project, we need a model to match the data the API is returning. This could be the point where a third project is added to allow the API and the Electron app to share common items, but just to keep the example simple I’m just going add a copy of the contact model from the API project to the Electron project.  The following is the full contact model class.

public class Contact
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Address { get; set; }
    public string City { get; set; }
    public string Subregion { get; set; }
    public string PostalCode { get; set; }
    public string Phone { get; set; }
    public string Email { get; set; }
}

Electron Views

Now that we have a model in our Electron project we need to create the views that go along with it. Start by adding the code generation package like we did above using the following command.

dotnet add package Microsoft.VisualStudio.Web.CodeGeneration.Design

Unfortunately, controller generation needs a DBContext to work which our project doesn’t have, so we have to take the long way about to generate our views and then manually create a controller to go with them. In order to get view generation to work, I had to add references to the Entity Framework Core Tools package using the following command.

dotnet add package Microsoft.EntityFrameworkCore.Tools

In the csproj file add the following .NET CLI tool reference.

<DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="2.0.2" />

Now the project is ready to use the command prompt to generate the views we will need for our CRUD operations related to our contacts. Use the following commands to create the full range of views needed (Create, Edit, List, Delete, Details).

dotnet aspnet-codegenerator view Create Create --model Contact --useDefaultLayout -outDir Views/Contacts

dotnet aspnet-codegenerator view Edit Edit --model Contact --useDefaultLayout -outDir Views/Contacts

dotnet aspnet-codegenerator view Index List --model Contact --useDefaultLayout -outDir Views/Contacts

dotnet aspnet-codegenerator view Delete Delete --model Contact --useDefaultLayout -outDir Views/Contacts

dotnet aspnet-codegenerator view Details Details --model Contact --useDefaultLayout -outDir Views/Contacts

Again there is a lot of switches when using aspnet-codegenerator. The following is a rundown of the ones used above.

  • view  tells the code generator we are creating a view
  • the next two items are the name of the view and the name of the view template
  • model is the model class that will be used for the generation
  • useDefaultLayout uses the default layout (surprise!)
  • outDir is the directory the output will be in relative to the current directory of your command prompt

The Index.cshtml generated above comes with links for Edit, Details, and Delete that won’t work as generated. Open the file and make the following changes to pass the key of the contact trying to be opened.

Before:
@Html.ActionLink("Edit", "Edit", new { /* id=item.PrimaryKey */ }) |
@Html.ActionLink("Details", "Details", new {/* id=item.PrimaryKey */ }) |
@Html.ActionLink("Delete", "Delete", new { /* id=item.PrimaryKey */ })

After:
@Html.ActionLink("Edit", "Edit", new {  id=item.Id }) |
@Html.ActionLink("Details", "Details", new { id=item.Id }) |
@Html.ActionLink("Delete", "Delete", new { id=item.Id })

Electron Controller

With the views complete let’s add a ContactsController.cs to the Controllers directory. The code for the controller follows, but I’m not going to go into the details. I took a controller from another contact base project and just replaces all the Entity Framework stuff with calls to the API we created above. Please don’t use this as an example of how something like this should be done it is just quick and dirty to show that it can work.

public class ContactsController : Controller
{
    private string _apiBaseUrl = "http://localhost:5000/api/contacts/";

    // GET: Contacts
    public async Task<IActionResult> Index()
    {
        using (var client = new HttpClient { BaseAddress = new Uri(_apiBaseUrl) })
        {
            return View(JsonConvert.DeserializeObject<List<Contact>>(await (await client.GetAsync("")).Content.ReadAsStringAsync()));
        }
    }

    // GET: Contacts/Details/5
    public async Task<IActionResult> Details(int? id)
    {
        if (id == null)
        {
            return NotFound();
        }

        using (var client = new HttpClient { BaseAddress = new Uri(_apiBaseUrl) })
        {
            var contact = JsonConvert.DeserializeObject<Contact>(await (await client.GetAsync(id.ToString())).Content.ReadAsStringAsync());

            if (contact == null)
            {
                return NotFound();
            }

            return View(contact);
        }
    }

    // GET: Contacts/Create
    public IActionResult Create()
    {
        return View();
    }

    // POST: Contacts/Create
    [HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Create([Bind("Id,Address,City,Email,Name,Phone,PostalCode,State")] Contact contact)
    {
        if (ModelState.IsValid)
        {
            using (var client = new HttpClient { BaseAddress = new Uri(_apiBaseUrl) })
            {
                await client.PostAsync("", new StringContent(JsonConvert.SerializeObject(contact), Encoding.UTF8, "application/json"));
            }

            return RedirectToAction("Index");
        }
        return View(contact);
    }

    // GET: Contacts/Edit/5
    public async Task<IActionResult> Edit(int? id)
    {
        if (id == null)
        {
            return NotFound();
        }

        using (var client = new HttpClient { BaseAddress = new Uri(_apiBaseUrl) })
        {
            var contact = JsonConvert.DeserializeObject<Contact>(await (await client.GetAsync(id.ToString())).Content.ReadAsStringAsync());

            if (contact == null)
            {
                return NotFound();
            }

            return View(contact);
        }
    }

    // POST: Contacts/Edit/5
    [HttpPost]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> Edit(int id, [Bind("Id,Address,City,Email,Name,Phone,PostalCode,State")] Contact contact)
    {
        if (id != contact.Id)
        {
            return NotFound();
        }

        if (ModelState.IsValid)
        {
            using (var client = new HttpClient { BaseAddress = new Uri(_apiBaseUrl) })
            {
                await client.PutAsync(id.ToString(), new StringContent(JsonConvert.SerializeObject(contact), Encoding.UTF8, "application/json"));
            }
            return RedirectToAction("Index");
        }
        return View(contact);
    }

    // GET: Contacts/Delete/5
    public async Task<IActionResult> Delete(int? id)
    {
        if (id == null)
        {
            return NotFound();
        }

        using (var client = new HttpClient { BaseAddress = new Uri(_apiBaseUrl) })
        {
            var contact = JsonConvert.DeserializeObject<Contact>(await (await client.GetAsync(id.ToString())).Content.ReadAsStringAsync());

            if (contact == null)
            {
                return NotFound();
            }

            return View(contact);
        }

    }

    // POST: Contacts/Delete/5
    [HttpPost, ActionName("Delete")]
    [ValidateAntiForgeryToken]
    public async Task<IActionResult> DeleteConfirmed(int id)
    {
        using (var client = new HttpClient { BaseAddress = new Uri(_apiBaseUrl) })
        {
            await client.DeleteAsync(id.ToString());
            return RedirectToAction("Index");
        }
    }

    private async Task<bool> ContactExists(int id)
    {
        using (var client = new HttpClient { BaseAddress = new Uri(_apiBaseUrl) })
        {
            return JsonConvert.DeserializeObject<Contact>(await (await client.GetAsync("id")).Content.ReadAsStringAsync()) != null;
        }
    }
}

Electron Add Link To Navigation

The final step to add a link to the list of contacts to the navigation bar of the application. Open the _Layout.cshtml and in the unordered list for the nav bar add the following line.

<li><a asp-area="" asp-controller="Contacts" asp-action="Index">Contacts</a></li>

Wrapping Up

That is all the changes to get the application up and running. If you run the API and then use dotnet electronize start from a command prompt in the ElectronTest project root all should be good to go.

The completed code can be found here.

Run Multiple Projects in Visual Studio Code

While expanding the sample used in the Electron.NET post to include an API I hit a snag with Visual Studio Code. I have used multiple projects with Visual Studio Code before, but never two distinct applications that I need to run at the same time.  Sample code that contains the two projects, but before any modifications covered in this post can be found here.

Building Multiple Projects

The first issue to tackle was getting both projects to build since they are technically independent. As I’m sure you are aware VS Code doesn’t need a solution file like full Visual Studio does. What I learned during this process was that while a solution file isn’t required once can be used to ensure multiple projects all get built. Using VS Code’s Terminal I ran the following commands to create a new solution and add my two projects to that solution.

dotnet new sln -n ElectronTest
dotnet sln add src/ElectronTest/ElectronTest.csproj
dotnet sln add src/ContactsApi/ContactsApi.csproj

With the solution file in place, I then opened the tasks.json file found in the .vscode directory. In the build task, I removed the path to a specific csproj file and just used the workspace folder.

Before:
"label": "build",
"command": "dotnet",
"type": "process",
"args": [
    "build",
    "${workspaceFolder}/src/ElectronTest/ElectronTest.csproj"
]

After:
"label": "build",
"command": "dotnet",
"type": "process",
"args": [
    "build",
    "${workspaceFolder}"
]

This is just one option on how to handle the builds. I believe another way would be to have two build tasks (one for each project) and use the individual build task in your launch configurations (which we are going to talk about next).

Debugging Multiple Projects

Open up your launch.json file in the .vscode directory. By default you will see a couple of configurations more than likely you will see one named .NET Core Attach and another named .NET Core Launch (web). It is the .NET Core Launch (web) configuration that we are interested in. This configuration controls how our application is launched. If you notice the program property points to the dll created during the build process, in the sample code this is  ${workspaceFolder}/src/ElectronTest/bin/Debug/netcoreapp2.0/ElectronTest.dll. This is all fine but doesn’t give us a way to run both of our projects. Let’s tweak the env property to set the ASPNETCORE_URLS which will control the URL the application is launched with.

Before:
"env": {
    "ASPNETCORE_ENVIRONMENT": "Development"
}

After:
"env": {
    "ASPNETCORE_ENVIRONMENT": "Development",
    "ASPNETCORE_URLS": "http://localhost:5001"
}

Now that the original application’s launch configuration is set we need to add a second launch configuration for our second application. The following is the full configuration section for my second application (the API).

{
    "name": ".NET Core Launch (API)",
    "type": "coreclr",
    "request": "launch",
    "preLaunchTask": "build",
    "program": "${workspaceRoot}/src/ContactsApi/bin/Debug/netcoreapp2.0/ContactsApi.dll",
    "args": [],
    "cwd": "${workspaceRoot}/src/ContactsApi",
    "stopAtEntry": false,
    "launchBrowser": {
        "enabled": false,
        "args": "${auto-detect-url}",
        "windows": {
            "command": "cmd.exe",
            "args": "/C start ${auto-detect-url}"
        },
        "osx": {
            "command": "open"
        },
        "linux": {
            "command": "xdg-open"
        }
    },
    "env": {
        "ASPNETCORE_ENVIRONMENT": "Development",
        "ASPNETCORE_URLS": "http://localhost:5000"
    },
    "sourceFileMap": {
        "/Views": "${workspaceRoot}/Views"
    }
}

I started with a copy of the original application and just modified a couple of things. First, the name property is now .NET Core Launch (API) which will help us know which application we are launching later. In the launchBrowser section, I set enabled to false since this is an API and I don’t need to launch the browser when the application starts. The final difference is in ASPNETCORE_URLS to make sure the URLs of the two applications are different. I used http://localhost:5000 in this example.

Now that all our configurations are good to go hop over to the debug section in VS Code.

On the debug you will notice that both of our launch configurations are listed. If you select the API one and hit the green play button it will start the API. With the API running you can then select the web configuration and hit the green play button and you will have both of your applications running in debug mode.

Wrapping Up

While it is not obvious at all how to get multiple applications to run in a single instance of VS Code the process isn’t hard after you do it the first time. I think my Visual Studio experience made figuring this out harder than it should have been. My key to learning how to get this going was on this GitHub issue.

Hopefully, this saved you some of the struggles I went through. Please leave a comment if there are different ways to accomplish this. The code with the final configuration can be found here.

Create a Desktop Application using ASP.NET Core and Electron.NET

Electron is a cross-platform (Windows, Linux, and Mac) library for building desktop applications using JavaScript, HTML, and CSS. Even if you have never head of Electron I’m sure you have used some of the desktop applications it has been used to build such as Visual Studio Code, Atom, Slack.

Electron.NET provides a wrapper around Electron with an ASP.NET Core MVC application in the mix. Here is the reason why this was done from the creates of the project.

Well… there are lots of different approaches how to get a X-plat desktop app running. We thought it would be nice for .NET devs to use the ASP.NET Core environment and just embed it inside a pretty robust X-plat enviroment called Electron. Porting Electron to .NET is not a goal of this project, at least we don’t have any clue how to do it. We just combine ASP.NET Core & Electron.

Project Creation

Seems only fitting to use VS Code for this post since it is built using the same base library. From the command line create a new ASP.NET Core MVC application using the following command.

dotnet new mvc

Make note that it is important at this time that you use the MVC template when attempting this and not a Razor Page application. This is more of a warning if you are using Visual Studio to do your project creation and not the CLI command above.

Next, we need to reference the ElectronNET.API NuGet package which can be added using the following command.

dotnet add package ElectronNet.API

Then, open the csproj and add a reference for the Electron.NET CLI tool which should match the following.

<ItemGroup>
     <DotNetCliToolReference Include="ElectronNET.CLI" Version="0.0.9" />
</ItemGroup>

After that make sure and restore packages using the following command.

dotnet restore

Wire-up Election.NET

Open Program.cs and add UseElectron(args) to the WebHost builder chain.

WebHost.CreateDefaultBuilder(args)
    .UseElectron(args)
    .UseStartup<Startup>()
    .Build();

Net, open Startup.cs and add the following line to the bottom of the Configure function. This is what will open the Electron window on startup.

Task.Run(async () => await Electron.WindowManager.CreateWindowAsync());

Finally, run the following from the command prompt to get the project ready to run under Electron. This should only need to be done once.

dotnet electronize init

Run the application

At this point, the application is ready to go. The neat part is you can just hit F5 and it will run like any normal ASP.NET Core application (this would change when you get into Electron specific calls I’m sure) or if you run the following command it will run inside of the Electron shell.

dotnet electronize start

Wrapping up

It was surprisingly simple to get a new application up and running, of course so far the app isn’t anything other than a web site hosted in Electron. My plan is to take this base application and create my normal basic contacts application, which will be the next post. From there I may look into layering in some Electron features.

The completed code can be found here.