WP8 SDK服务进口与参考不能基于任务的操作 [英] WP8 SDK import Service Reference with task-based operations not possible

问题描述

到目前为止，这似乎与进口生成基于任务的操作，在VS2012服务引用不工作。它的操作系统变灰。

与WPF一个新的项目工作正常的测试 - 我可以选择基于任务的异步或操作

有没有在一个任务包的异步调用一个简单的方法？

解决方案

  

有没有在一个任务包的异步调用一个简单的方法？

举例 WebClient.DownloadStringCompleted

 公共静态类WebClientAsyncExtensions
{
    公共静态任务＆LT;串GT; DownloadStringTask（这WebClient的客户，URI地址）
    {
        VAR TCS =新TaskCompletionSource＆LT;串GT;（）;        DownloadStringCompletedEventHandler处理器= NULL;
        处理器=（发件人，E）=＆GT;
            {
                client.DownloadStringCompleted  -  =处理程序;                如果（e.Error！= NULL）
                {
                    tcs.SetException（e.Error）;
                }
                其他
                {
                    tcs.SetResult（e.Result）;
                }
            };        client.DownloadStringCompleted + =处理程序;
        client.DownloadStringAsync（地址）;        返回tcs.Task;
    }
}
 

用法：

 异步无效DownloadExample（）
{
    Web客户端的客户端=新的WebClient（）;
    等待client.DownloadStringTask（新的URI（HTTP：// HTTP：//stackoverflow.com/questions/13266079/））;
}
 

So far it seems that importing a service reference in VS2012 with "generate task-based operations" is not working. It os greyed out.

A test with a new project for WPF is working fine - I could select either task-based or async operations.

Is there a simple way on wrapping the async call in a task?

解决方案

Is there a simple way on wrapping the async call in a task?

Example for WebClient.DownloadStringCompleted

public static class WebClientAsyncExtensions
{
    public static Task<string> DownloadStringTask(this WebClient client, Uri address)
    {
        var tcs = new TaskCompletionSource<string>();

        DownloadStringCompletedEventHandler handler = null;
        handler = (sender, e) =>
            {
                client.DownloadStringCompleted -= handler;

                if (e.Error != null)
                {
                    tcs.SetException(e.Error);
                }
                else
                {
                    tcs.SetResult(e.Result);
                }
            };

        client.DownloadStringCompleted += handler;
        client.DownloadStringAsync(address);

        return tcs.Task;
    }
}

Usage:

async void DownloadExample()
{
    WebClient client = new WebClient();
    await client.DownloadStringTask(new Uri("http://http://stackoverflow.com/questions/13266079/"));
}

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