如何在SIlverlight中实现对WCF服务的同步调用？

[ServiceContract]
public interface IMyService
{
    [OperationContract]
    string GetData(int value);
}

public class MyService : IMyService
{
    public string GetData(int value)
    {
        return string.Format("You entered: {0}", value);
    }
}

private void Button_Click(object sender, RoutedEventArgs e)
{
    MyServiceClient client = new MyServiceClient();
    client.GetDataCompleted += Client_GetDataCompleted;
    client.GetDataAsync(123);
}

private void Client_GetDataCompleted(object sender, GetDataCompletedEventArgs e)
{
    string result = e.Result;
    // 处理结果
}

private void Button_Click(object sender, RoutedEventArgs e)
{
    MyServiceClient client = new MyServiceClient();
    AutoResetEvent waitHandle = new AutoResetEvent(false);
    string result = null;
    client.GetDataCompleted += (s, args) =>
    {
        result = args.Result;
        waitHandle.Set();
    };
    client.GetDataAsync(123);
    waitHandle.WaitOne();
    // 处理结果
}