How can I use async/await to call a webservice?

Question

I have a webservice written in Yii (php framework).

I use C# and Visual Studio 2012 to develop a WP8 application. I added a service reference to my project (Add Serv

Answer 1

(Copied from OP, per https://meta.stackexchange.com/a/150228/136378 )

Answer:

Following code seems to work.

internal static class Extension
{
    private static void TransferCompletion(
        TaskCompletionSource tcs, System.ComponentModel.AsyncCompletedEventArgs e, 
        Func getResult)
    {
        if (e.Error != null)
        {
            tcs.TrySetException(e.Error);
        }
        else if (e.Cancelled)
        {
            tcs.TrySetCanceled();
        }
        else
        {
            tcs.TrySetResult(getResult());
        }
    }

    public static Task LoginAsyncTask(
        this YChatWebService.WebServiceControllerPortTypeClient client,
        string userName, string password)
    {
        var tcs = new TaskCompletionSource();
        client.loginCompleted += (s, e) => TransferCompletion(tcs, e, () => e);
        client.loginAsync(userName, password);
        return tcs.Task;
    }
}

I call it this way

client = new YChatWebService.WebServiceControllerPortTypeClient();
var login = await client.LoginAsyncTask(this.username, this.password);