C＃进度条未与下载同步（WebClient类）

Question

I am coding a system which has a small FTP module included inside, it's not the main feature at all, but needed...

I must link the progressbar with the WebClient class event DownloadProgressChangedEventHandler and AsyncCompletedEventHandler, the progressbar increment is ok, and the ASyncCompletedEventHandler launch a MessageBox (as intended), the problem is that the progress bar see to load too slow...

problem :

My MessageBox pop at 100% (launched by the event handler), BUT when the MessageBox pop my progress bar is only at +-80% (but the .VALUE is really 100), the first though I had was that they have added a "smooth" effect in Windows Vista which slow down the progressbar relatively to it's true value.

If any of you have experienced the same problem thanks for your help.

Answer 1

For those of you who want to know, Vista actually add a "smoothing" to the loadingbar change, it look like the "Tweening effect" of Flash.

I tried on Windows XP and the bar reach 100% exactly when the value reach 100. On Vista it look like they have decided that the "loading" would be splitted over a delay X.

Answer 2

Before you display your message box, call Application.DoEvents() to force all the pending Windows queued messages to be processed. Your progress bar is probably not getting a chance to paint itself one last time before the message box displays.

Answer 3

为什么不在显示消息框的同一DownloadProgressChangedEventHandler事件处理程序中将进度条值设置为100％？