If you're on a Mac with an Apple M1 chip, you need to install the Arm64 version of the SDK.
Check everything installed correctly
Once you've installed, open a new terminal and run the following command:
Command prompt
dotnet
If the installation succeeded, you should see an output similar to the following:
Command prompt
Usage: dotnet [options]Usage: dotnet [path-to-application]Options:-h|--help Display help.--info Display .NET information.--list-sdks Display the installed SDKs.--list-runtimes Display the installed runtimes.path-to-application:The path to an application .dll file to execute.
If everything looks good, select the Continue button below to go to the next step.
Got an error?
If you receive a zsh: command not found: dotnet error, make sure you opened a new terminal window. If you can't resolve the issue, use the I ran into an issue button to get help fixing the problem.
If you receive a dotnet: command not found error, make sure you opened a new terminal window. If you can't resolve the issue, use the I ran into an issue button to get help fixing the problem.
Create your app
Start Visual Studio and select Create a new project.
In the Create a new project window, type Blazor on the search box and hit Enter.
Select the Blazor Server App template and select Next.
In the Configure your new project window, enter BlazorApp as the project name and select Next.
In the Additional information window, select .NET 7.0 (Standard Term Support) in the Framework drop-down if not already selected and click the Create button.
Your project is created and loaded in Visual Studio. Take a look at the contents of your project using Solution Explorer.
Several files were created to give you a simple Blazor app that is ready to run.
Program.cs is the entry point for the app that starts the server and where you configure the app services and middleware.
App.razor is the root component for the app.
The Pages directory contains some example web pages for the app.
BlazorApp.csproj defines the app project and its dependencies and can be viewed by double-clicking the BlazorApp project node in the Solution Explorer.
The launchSettings.json file inside the Properties directory defines different profile settings for the local development environment. A port number is automatically assigned at project creation and saved on this file.
If everything looks good, select the Continue button below to go to the next step.
In your terminal, run the following command to create your app:
Command prompt
dotnet new blazorserver -o BlazorApp --no-https -f net7.0
This command creates your new Blazor app project and places it in a new directory called BlazorApp inside your current location.
Navigate to the new BlazorApp directory created by the previous command:
Command prompt
cd BlazorApp
Take a quick look at the contents of the BlazorApp directory. Several files were created in the BlazorApp directory, to give you a simple Blazor app that is ready to run.
Program.cs is the entry point for the app that starts the server and where you configure the app services and middleware.
App.razor is the root component for the app.
The Pages directory contains some example web pages for the app.
BlazorApp.csproj defines the app project and its dependencies.
The launchSettings.json file inside the Properties directory defines different profile settings for the local development environment. A port number ranging between 5000-5300 is automatically assigned at project creation and saved on this file.
Take note of the BlazorApp directory path as you will use it later in the tutorial.
If everything looks good, select the Continue button below to go to the next step.
Run your app
Click on the Start Debugging button (green arrow) in the Debug Toolbar in Visual Studio to run your app.
Once the app is running, you can apply code changes to the running app by clicking the Hot Reload button.
You can stop the app at any time by clicking on the Stop button in the top toolbar.
The first time you run a web app in Visual Studio, it will set up a development certificate for hosting the app over HTTPS and then prompt you to trust the certificate. We recommend agreeing to trust the certificate. The certificate will only be used for local development, and without it most browsers will complain about the security of the website.
Wait for the app to launch in the browser. Once you get to the following page, you have successfully run your first Blazor app!
In your terminal, run the following command:
Command prompt
dotnet watch
The dotnet watch command will build and start the app, and then update the app whenever you make code changes. You can stop the app at any time by selecting Ctrl+C.
Wait for the app to display that it's listening on http://localhost:<port number> and for the browser to launch at that address.
Wait for the app to display that it's listening on http://localhost:<port number> and then open a browser and navigate to that address. In this example, dotnet watch showed it was listening on http://localhost:7178.
Once you get to the following page, you have successfully run your first Blazor app!
The displayed page is defined by the Index.razor file located inside the Pages directory. This is what its contents look like:
Pages/Index.razor
@page "/"<PageTitle>Index</PageTitle><h1>Hello, world!</h1>Welcome to your new app.<SurveyPrompt Title="How is Blazor working for you?" />
It already contains the code that sets it as the homepage and displays the text Hello, world! and Welcome to your new app. It also includes a SurveyPrompt component that renders a link to the Blazor feedback survey.
Got an error?
If you receive an error message saying "Your connection is not private" with error code NET::ERR_CERT_INVALID, try to restart all browser windows so the new certificate can be picked up by the browser and run the application again.
If you can't resolve the issue you're having, select the I ran into an issue button below to get help fixing the problem.
Try the counter
In the running app, navigate to the Counter page by clicking the Counter tab in the sidebar on the left. The following page should then be displayed:
Select the Click me button to increment the count without a page refresh. Incrementing a counter in a webpage normally requires writing JavaScript, but with Blazor you can use C#.
You can find the implementation of the Counter component at Counter.razor file located inside the Pages directory.
A request for /counter in the browser, as specified by the @page directive at the top, causes the Counter component to render its content.
Each time the Click me button is selected:
The onclick event is fired.
The IncrementCount method is called.
The currentCount is incremented.
The component is rendered to show the updated count.
Add a component
Each of the .razor files defines a UI component that can be reused.
Open the Index.razor file in Visual Studio. The Index.razor file already exists, and it was created when you created the project. It's located in the Pages folder inside the BlazorApp directory that was created earlier.
Open the Index.razor file in a text editor of your choice. The Index.razor file already exists, and it was created when you ran the dotnet new command. It's located in the Pages folder inside the BlazorApp directory that was created earlier.
Add a Counter component to the app's homepage by adding a <Counter /> element at the end of the Index.razor file.
Pages/Index.razor
@page "/"<PageTitle>Index</PageTitle><h1>Hello, world!</h1>Welcome to your new app.<SurveyPrompt Title="How is Blazor working for you?" /><Counter />
Click the Hot Reload button to apply the change to the running app. The Counter component will then show up on the home page.
Once this change is saved, the dotnet watch command will apply the change to the running app so that the Counter component shows up on the home page.
Modify a component
Component parameters are specified using attributes or child content, which allow you to set properties on the child component. Define a parameter on the Counter component for specifying how much it increments with every button click:
Add a public property for IncrementAmount with a [Parameter] attribute.
Change the IncrementCount method to use the IncrementAmount when incrementing the value of currentCount.
The following code shows how to achieve that. The highlighted lines show the changes.
In Index.razor, update the <Counter> element to add an IncrementAmount attribute that changes the increment amount to ten as shown by the highlighted line in the following code:
Pages/Index.razor
@page "/"<h1>Hello, world!</h1>Welcome to your new app.<SurveyPrompt Title="How is Blazor working for you?" /><Counter IncrementAmount="10" />
Apply the change to the app by clicking the Hot Reload button. The Index component now has its own counter that increments by ten each time the Click me button is selected, as shown in the following image. The Counter component (Counter.razor) at /counter continues to increment by one.
The Index component now has its own counter that increments by ten each time the Click me button is selected, as shown in the following image. The Counter component (Counter.razor) at /counter continues to increment by one.
Next steps
Congratulations, you've built and run your first Blazor app!
Keep learning
Now that you've got the basics, continue building your first Blazor app with Blazor self-guided learning module on Microsoft Learn where you will build a to-do list app.
Go through the 6-part Intro to Web Development with .NET series! Here, you'll build awesome projects and learn all about Razor Pages, Minimal APIs, Blazor, and more.
