如何终止运行功能？

Question

我找到了simple progressbar dialog class并尝试在我的应用中使用它。

除非单击取消和进度条对话框调用worker.CancelAsync();，否则一切似乎都没问题。发生这种情况时，我的流程仍在等待结束。

很难理解所以我粘贴了我的代码。问题是：当progressbardialog调用worker.CancelAsync();

时，如何完全终止'engine'函数的运行

class LibWrap //containing the LONG process with dll 
{ 
public bool cancelThisBoringProcess; 
public int currentPecentage; 
public delegate void  pfnCallback(int progress, out bool cancel); 
public void showProgress(int progress, out bool cancel) 
{ 
 cancel = cancelThisBoringProcess;  
 currentPecentage = progress; 
}  
[DllImport("Lib.DLL", CallingConvention = CallingConvention.Cdecl)] 
 public unsafe static extern byte* bufferOp(byte* data,pfnCallback del); 
public unsafe  BitmapFrame engine(BitmapFrame incomingFrame) 
{ 
//... 
 fixed (byte* inBuf = incoming) 
 { 
var callback = new pfnCallback(showProgress); 
byte* outBuf = bufferOp(inBuf, callback);//this is DLL function with callback to get out percentage //and pass cancel 
      GC.KeepAlive(callback); 
//.... 
} 
} 
} 
class Main 
{ 
void OnClick(object sender, RoutedEventArgs e) 
{ 
ProgressDialog dlg = new ProgressDialog(""); 
LibWrap lwrap = new LibWrap(); 
DoWorkEventHandler handler = delegate { BitmapFrame bf = lwrap.engine(img)); }; 

            dlg.AutoIncrementInterval = 100; 
            dlg.IsCancellingEnabled = true; 
            dlg.Owner = Application.Current.MainWindow; 
            dlg.RunWorkerThread(handler); 
} 
}