独立的 Blazor Webassembly (PWA) 是否支持会话存储（未托管在 asp.net 核心中）？

Question

我的 class 中有以下代码继承自 AuthenticationStateProvider

public async override Task<AuthenticationState> GetAuthenticationStateAsync()
        {    
            if (sessionStorageService.ContainKeyAsync("UserProfile").Result)
            {
                var mAUser = await sessionStorageService.GetItemAsync<MAUser>("UserProfile");
                return await Task.FromResult(BuildAuthenticationState(mAUser));
            }
            else
            {
                return Anonymous;
            }
        }

我在线上收到错误：

if (sessionStorageService.ContainKeyAsync("UserProfile").Result)

错误是：

Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100]
      Unhandled exception rendering component: Cannot wait on monitors on this runtime.
System.PlatformNotSupportedException: Cannot wait on monitors on this runtime.
   at System.Threading.Monitor.ObjWait(Boolean exitContext, Int32 millisecondsTimeout, Object obj)
   at System.Threading.Monitor.Wait(Object obj, Int32 millisecondsTimeout, Boolean exitContext)
   at System.Threading.Monitor.Wait(Object obj, Int32 millisecondsTimeout)
   at System.Threading.ManualResetEventSlim.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task.SpinThenBlockingWait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task.InternalWaitCore(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task.InternalWait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task`1[[System.Boolean, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].GetResultCore(Boolean waitCompletionNotification)
   at System.Threading.Tasks.Task`1[[System.Boolean, System.Private.CoreLib, Version=5.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].get_Result()
   at MyAushadhaBlazor.Auth.AuthStateProvider.GetAuthenticationStateAsync() in C:\xxx\xxxx\xxx\xxx\xxx\BlazorApp1\Auth\AuthStateProvider.cs:line 40
   at Microsoft.AspNetCore.Components.Authorization.AuthorizeViewCore.OnParametersSetAsync()
   at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
   at Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync()

Answer 1

与 Blazor Server 相比，Blazor WASM 对任务计划程序的支持有限。 .GetAwaiter().GetResult() 之类的东西在 Blazor WASM 中不起作用。这解释了您的错误消息

无法在此运行时等待监视器

如果您在 ContainKeyAsync 前面添加一个 await 并删除 .Result 它应该可以工作。

public async override Task<AuthenticationState> GetAuthenticationStateAsync()
{    
    if (await sessionStorageService.ContainKeyAsync("UserProfile"))
    {
        var mAUser = await sessionStorageService.GetItemAsync<MAUser>("UserProfile");
        return await Task.FromResult(BuildAuthenticationState(mAUser));
    }
    else
    {
        return Anonymous;
    }
}

独立的 Blazor Webassembly (PWA) 是否支持会话存储（未托管在 asp.net 核心中）？

Is session storage supported in Blazor Webassembly (PWA) standalone (Not hosted in asp.net core)?

c#

asp.net

blazor-webassembly

.net-5

asp.net-blazor