If you're on a Mac with an Apple M1 or M2 chip, you need to install the Arm64 version of the SDK.
Check everything installed correctly
Once you've installed, open a new command prompt and run the following command:
Once you've installed, open a new terminal and run the following command:
Command prompt
dotnet --version
If the installation succeeded, you should see version 8.0.100 or higher outputted:
Command prompt
8.0.100
If everything looks good, select the Continue button below to go to the next step.
Got an error?
If you receive a 'dotnet' is not recognized as an internal or external command error, make sure you opened a new command prompt. If quickly restarting your machine doesn't resolve the issue, use the I ran into an issue button to get help fixing the problem.
Create your app
In your command prompt, run the following command to create your app:
Command prompt
dotnet new blazor -o BlazorApp
This command creates your new Blazor Web 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.
Command prompt
dir
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.
Inside the Components directory:
App.razor is the root component for the app.
Routes.razor configures the Blazor router.
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 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.
Got an error?
If you receive a message similar to Template "Blazor Web App" could not be created. Access to the path 'C:\Windows\System32\BlazorApp' is denied, change your current directory to one where you have permissions to create a new folder and try to run the command again.
If Windows can't find the SDK when you try to create the project and you are sure you have installed the SDK, your machine might have an issue with the PATH environment variable. See this Stack Overflow post for instructions on how to diagnose and fix this issue.
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.
Run your app
In your command prompt, 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.
Once you get to the following page, you have successfully run your first Blazor app!
The displayed page is defined by the Home.razor file located inside the Components/Pages directory. This is what its contents look like:
Components/Pages/Home.razor
@page "/"<PageTitle>Home</PageTitle><h1>Hello, world!</h1>Welcome to your new app.
It already contains the code that sets it as the homepage and displays the text Hello, world! and Welcome to your new app. The PageTitle component sets the title for the current page so that it shows up in the browser tab.
Got an error?
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 Components/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 Home.razor file in a text editor of your choice. The Home.razor file already exists, and it was created when you ran the dotnet new command. It's located in the Components/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 Home.razor file.
Components/Pages/Home.razor
@page "/"<PageTitle>Home</PageTitle><h1>Hello, world!</h1>Welcome to your new app.<Counter />
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 Home.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:
Components/Pages/Home.razor
@page "/"<PageTitle>Home</PageTitle><h1>Hello, world!</h1>Welcome to your new app.<Counter IncrementAmount="10" />
The Home 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.
