C＃的IAsyncResult爲WaitAll

Question

在一些了WaitAll的實現我看到下面的代碼

IAsyncResult result1 = Method.BeginInvoke(10, MyCallback, null) 
IAsyncResult result2 = Method.BeginInvoke(20, MyCallback, null) 
WaitHandle[] waitHandles = new WaitHandle[] { result1.AsyncWaitHandle, result2.AsyncWaitHandle}; 
WaitHandle.WaitAll(waitHandles) 

這看起來對嗎？在創建waitHandles數組之前，其中一個調用完成之後有什麼機會？

問候， Dhananjay

Answer 1

對我來說很有意義。

// Begin invoking the first and second method, and give them a callback 
IAsyncResult result1 = Method.BeginInvoke(10, MyCallback, null) 
IAsyncResult result2 = Method.BeginInvoke(20, MyCallback, null) 

// Any time past the point of invokation, MyCallback could be called. 
// Get the wait handles of the async results, regardless of whether they have finished or not 
WaitHandle[] waitHandles = new WaitHandle[] { result1.AsyncWaitHandle, result2.AsyncWaitHandle}; 

// Make sure to wait until the methods have finished. 
// They could have finished immediately, and MyCallback could have already been called, 
// but we will never get past this line unless they have finished. 
WaitHandle.WaitAll(waitHandles) 
// We may have waited on the function to finish, or they may have been done before we arrived at the previous line. Either way, they are done now. 

你究竟發現了什麼奇怪的東西？

問「有什麼機會」是一個不好的跡象。機會是它可能發生這意味着如果在WaitAll之前完成這些方法，您需要說明該程序需要做什麼。