public void Init()
{
AsyncComputeCaller caller = new AsyncComputeCaller(this.Cal_num);
AsyncCallback callback = new AsyncCallback(ComputerCallback);
//BeginInvoke不会阻塞，实现异步调用 执行传入的ComputerCallback的回调方法
caller.BeginInvoke(num1, num2, callback, caller);
}
/// <summary>
/// 执行后续处理，可以在UI线程中直接更新界面不会有阻塞，假死
/// </summary>
/// <param name="result"></param>
private void ComputerCallback(IAsyncResult result)
{
AsyncComputeCaller caller = (AsyncComputeCaller)result.AsyncState;
caller.EndInvoke(result);
}