如何在Windows Phone 8中同步调用异步方法(How to call asynchronous method synchronously in Windows Phone 8)

 我们已经使用Xamarin.Forms开发了现有的iOS应用程序。 现在我们想要扩展到Android和Windows Phone。 在现有应用程序中，所有Web服务调用都是同步进行的。 Windows phone仅支持异步调用，因此我们考虑将异步调用包装为同步。 
 
 我们使用HttpClient.PostAsync方法来访问服务。 一旦执行命中PostAsync方法，手机就会挂起。 调用服务的代码如下： 
 
private static async void CallService(System.Uri uri)
{
    using (HttpClient client = new HttpClient())
    {
        client.DefaultRequestHeaders.Host = uri.Host;
        client.Timeout = System.TimeSpan.FromSeconds(30);
        HttpContent content = new StringContent("", Encoding.UTF8, "application/xml");

        var configuredClient = client.PostAsync(uri, content).ConfigureAwait(false);
        var resp = configuredClient.GetAwaiter().GetResult();
        resp.EnsureSuccessStatusCode();
        responseString = resp.StatusCode.ToString();
        resp.Dispose();

        client.CancelPendingRequests();
        client.Dispose();
    }
}
 
 我知道这是因为阻止了UI线程，所以只有我实现了ConfigureAwait（false），但这根本不起作用。 我尝试使用System.Net.WebClient但结果相同。 
 
 现在，我将如何使这个异步调用在Windows Phone 8中同步处理？ 

We have existing iOS application developed using Xamarin.Forms. Now we want to extend to both Android and Windows Phone. In the existing application, all the web service calls are made synchronously. Windows phone supports only asynchronous calling, so we thought of wrapping the asynchronous calls to synchronous. 
 
We are using HttpClient.PostAsync method to access the service. Once the execution hits PostAsync method, the phone hangs. The code to call the service is as follows:
 
private static async void CallService(System.Uri uri)
{
    using (HttpClient client = new HttpClient())
    {
        client.DefaultRequestHeaders.Host = uri.Host;
        client.Timeout = System.TimeSpan.FromSeconds(30);
        HttpContent content = new StringContent("", Encoding.UTF8, "application/xml");

        var configuredClient = client.PostAsync(uri, content).ConfigureAwait(false);
        var resp = configuredClient.GetAwaiter().GetResult();
        resp.EnsureSuccessStatusCode();
        responseString = resp.StatusCode.ToString();
        resp.Dispose();

        client.CancelPendingRequests();
        client.Dispose();
    }
}
 
I know this is because of blocking the UI thread, so only I implemented ConfigureAwait(false) but that didn't work at all. I tried with System.Net.WebClient also but the same result. 
 
Now, how I will make this asynchronous call to process synchronously in Windows Phone 8?

原文：https://stackoverflow.com/questions/26889789