@page "/" @if (SelectedProfile != null) { <div> <MatSelectItem Items=@Profiles Outlined=true TValue="Profile" @bind-Value=@SelectedProfile> <ItemTemplate Context="profile"> @profile.Id - @profile.Name </ItemTemplate> </MatSelectItem> </div> <div class="mt-2"> <MatTextField Outlined=true TValue="string" Value=@SelectedProfile.Name ValueChanged=@OnNameChanged /> </div> } @code { protected List<Profile> Profiles { get; set; } protected Profile SelectedProfile { get; set; } protected override void OnInitialized() { base.OnInitialized(); Profiles = new List<Profile> { new Profile { Id = 0, Name = "Profile 1" }, new Profile { Id = 0, Name = "Profile 2" }, new Profile { Id = 1, Name = "Profile 3" }, new Profile { Id = 2, Name = "Profile 4" } }; SelectedProfile = Profiles[0]; } protected void OnNameChanged(string name) { SelectedProfile.Name = name; } public class Profile { public int Id { get; set; } public string Name { get; set; } } }
namespace BlazorFiddleProject { using Microsoft.Extensions.DependencyInjection; public class Startup { public void ConfigureServices(IServiceCollection services) { } public void Configure(IComponentsApplicationBuilder app) { app.AddComponent<App>("app"); } } }
<!DOCTYPE html> <html> <head> <meta charset="utf-8"/> <meta name="viewport" content="width=device-width"> <title>BlazorFiddleProject</title> <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous"> <link href="_content/MatBlazor/dist/matBlazor.css" rel="stylesheet" /> <style> app { } </style> <script type="text/javascript"> </script> </head> <body> <app>Loading...</app> <script src="_content/MatBlazor/dist/matBlazor.js"></script> <script src="_framework/blazor.webassembly.js"></script> <script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script> <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script> </body> </html>

Add component

BlazorFiddle was updated from Blazor 0.7 to .NET 6.0. Your old source code could not work. You need to upgrade to latest.