当在生产环境中使用Blazor WASM时，您可能会遇到以下错误消息：'An unhandled exception occurred while processing the request.” 这个错误消息并不是非常有帮助，因为它没有提供任何关于错误原因的详细信息。但是，您可以使用以下步骤来获取Blazor WASM应用程序中出现问题的更具体的信息。

1.在页面上添加以下代码：

@if (isDevelopment) {

@Json.Serialize(error, new JsonSerializerOptions { WriteIndented = true })

2.在App.razor文件中创建一个isDevelopment属性，并在OnInitialized方法中设置它的值：

@code { private bool isDevelopment;

protected override void OnInitialized()
{
    isDevelopment = !String.Equals(env.EnvironmentName, "production", StringComparison.OrdinalIgnoreCase);
}

}

3.在Startup.cs文件中添加以下代码：

app.UseExceptionHandler("/Error");

app.UseMiddleware();

4.在BlazorProductionExceptionHandlerMiddleware.cs 文件中添加以下代码：

app.UseExceptionHandler("/Error");

app.UseMiddleware();

代码：

using Microsoft.AspNetCore.Builder; using Microsoft.AspNetCore.Diagnostics; using Microsoft.AspNetCore.Hosting; using Microsoft.AspNetCore.Http; using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Text.Json; using System.Threading.Tasks;

namespace BlazorApp1.Server.Middleware { public class BlazorProductionExceptionHandlerMiddleware { public async Task InvokeAsync(HttpContext context) { var exceptionHandlerPathFeature = context.Features.Get();

        if (exceptionHandlerPathFeature?.Error != null)
        {
            context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
            context.Response.ContentType = "application/json";
            
            var error = new
            {
                exceptionHandlerPathFeature.Error.Message,
                exceptionHandlerPathFeature.Error.StackTrace,
                InnerException = exceptionHandlerPathFeature.Error.InnerException != null ? new
                {
                    exceptionHandlerPathFeature.Error.InnerException.Message,
                    exceptionHandlerPathFeature.Error.InnerException.StackTrace
                } : null
            };

            await context.Response.WriteAsync(JsonSerializer.Serialize(error));
        }
    }
}

// Extension method used to add the middleware to the HTTP request pipeline.
public static class BlazorProductionExceptionHandlerMiddlewareExtensions
{
    public static IApplicationBuilder UseBlazorProductionExceptionHandler(
        this IApplicationBuilder builder)
    {
        return builder.UseMiddleware();
    }
}

}

5.在Error.razor文件中添加以下代码：

@if (Error != null) { @if (IsDevelopment) {