Question

我正在尝试使用ExecuteAsync<T>制作异步获取请求，但它从不响应。让我感到困惑的是，ExecuteAsync和Execute以及Execute<T>同步方法都有效。

这是我的代码：

var restClient = new RestClient("http://localhost:44268/api/");
var request = new RestRequest("jobs/{id}", Method.GET);
request.AddUrlSegment("id", "194");

// works
var req1 = restClient.Execute(request).Content;

// works
var req2 = restClient.Execute<Job>(request).Content;

// works
var req3 = restClient.ExecuteAsync(request, (restResponse) =>
{
    var test = restResponse.Content;
    Console.WriteLine(test);
});

var req4 = restClient.ExecuteAsync<Job>(request, (restResponse) =>
{
    // this code is never reached
    var test = restResponse.Content;
    Console.WriteLine(test);
});

是成功调用API，但它永远不会回调。为什么？我做错了吗？

Answer 1

ExecuteAsync是异步的。

这意味着对它的调用立即返回而不等待响应。

然后你的程序正常继续。如果这是一个控制台应用程序并且执行到了Main方法的末尾，则整个程序将退出。

所以，你有一个竞争条件。大多数情况下，程序将在continuation（lambda回调）有机会运行之前退出。

尝试在Console.ReadLine();方法的末尾发出Main来电，以防止提前退出。

Answer 2

通过升级到最新版本的RestSharp解决了这个问题。

Answer 3

public  Task<IRestResponse> ExecuteAsync<T>(RestRequest request, RestClient client)
{
  EventWaitHandle executedCallBack = new AutoResetEvent(false);
  TaskCompletionSource<IRestResponse> tcs = new TaskCompletionSource<IRestResponse>();

IRestResponse res = new RestResponse();   
    try
    {
      var asyncHandle = client.ExecuteAsync<RestResponse>(request, response =>
        {
          res = response;
          tcs.TrySetResult(res);
          executedCallBack.Set();
        });


    }
    catch (Exception ex)
    {
      tcs.TrySetException(ex);
    }

    return tcs.Task;
}

Answer 4

IRestResponse loginResponse = new RestResponse();
                    TaskCompletionSource<IRestResponse> tcs = new TaskCompletionSource<IRestResponse>();

//Task task = new Task(() => {client.ExecuteAsync<RestResponse>(request, tcs.SetResult);});// Lambda and anonymous method  
Task task = new Task(() =>client.ExecuteAsync<RestResponse>(request, tcs.SetResult)); // Lambda and named method                    
task.Start();
loginResponse = await tcs.Task;

RestSharp：ExecuteAsync <t>永不响应</t>

4 个答案: