Csharp 无法连接到 .Net Core Blazor WASM 应用程序中的 WebSocket 控制器

我正在try 在我的WASM应用程序中建立WebSocket连接. 我遵循了MSDN教程，并在我的Program.cs中启用了WebSockets:

app.UseWebSockets();

在那之后，我添加了一个新的控制器，如下所示:

[AllowAnonymous]
[ApiController]
[Route("[controller]")]
internal class ShellyPlusDataController : ControllerBase
{
    [HttpGet]
    [Route("[controller]/OnDataReceived")]
    public async Task OnDataReceived()
    {
        if (HttpContext.WebSockets.IsWebSocketRequest)
        {
            using var webSocket = await HttpContext.WebSockets.AcceptWebSocketAsync();

            var buffer = new byte[1024 * 4];
            WebSocketReceiveResult result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);

            while (!result.CloseStatus.HasValue)
            {
                string raw = Encoding.UTF8.GetString(buffer, 0, result.Count);
                result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);
            }

            await webSocket.CloseAsync(result.CloseStatus.Value, result.CloseStatusDescription, CancellationToken.None);
        }
        else
        {
            HttpContext.Response.StatusCode = StatusCodes.Status400BadRequest;
        }
    }
}

用PostMan打开与‘wss://localhost:7220/ShellyPlusData/OnDataReceived’的连接不起作用.显示的错误为:Error: Unexpected server response: 200

我在OnDataReceived()的开头设置了一个断点；它从未命中. 我还try 将URL更改为ws://或省略方法名称，但没有成功.

微软的教程也在Program.cs中建议这样做:

app.Use(async (context, next) =>
{
    if (context.Request.Path == "/ws")
    {
        if (context.WebSockets.IsWebSocketRequest)
        {
            using var webSocket = await context.WebSockets.AcceptWebSocketAsync();
            await Echo(webSocket);
        }
        else
        {
            context.Response.StatusCode = StatusCodes.Status400BadRequest;
        }
    }
    else
    {
        await next(context);
    }
});

也不管用. 有什么建议吗？