//http://dotnetstep.blogspot.com/2009/01/threadpool-wait-for-all-thread-to.html
void ThreadFunctionImageProcess(object threadobj)
{
ThreadPoolObj obj = threadobj as ThreadPoolObj;
if (obj != null)
{
//Console.WriteLine(obj.ObjectID.ToString());
Console.WriteLine("{0} on thread {1}", obj.picSrcPath, Thread.CurrentThread.ManagedThreadId);
ResizeImagesTask(obj.picSrcPath, obj.picDestPath, obj.picScale);
obj.signal.Set();
}
}
/// <summary>
/// 進行圖片的縮放作業
/// </summary>
/// <param name="sourcePath">圖片來源目錄路徑</param>
/// <param name="destPath">產生圖片目的目錄路徑</param>
/// <param name="scale">縮放比例</param>
public void ResizeImages(string sourcePath, string destPath, double scale)
{
Stopwatch sw = new Stopwatch();
sw.Start();
var allFiles = FindImages(sourcePath);
List <ManualResetEvent> events = new List <ManualResetEvent>();
int fileCounter = 0;
foreach (var filePath in allFiles)
{
fileCounter++;
//寫法一:等待全部Thread 都已經 Complete
//參考 http://dotnetstep.blogspot.com/2009/01/threadpool-wait-for-all-thread-to.html
ThreadPoolObj tpobj = new ThreadPoolObj();
tpobj.ObjectID = fileCounter;
tpobj.signal = new ManualResetEvent(false);
tpobj.picSrcPath = filePath;
tpobj.picDestPath = destPath;
tpobj.picScale = scale;
events.Add(tpobj.signal);
WaitCallback callback = new WaitCallback(ThreadFunctionImageProcess);
ThreadPool.SetMinThreads(4, 4);
ThreadPool.SetMaxThreads(12, 12);
ThreadPool.QueueUserWorkItem(callback, tpobj);
//寫法=二:
//ThreadPool.QueueUserWorkItem((state) =>
//{
// Console.WriteLine("{0} on thread {1}", filePath, Thread.CurrentThread.ManagedThreadId);
// ResizeImagesTask(filePath, destPath, scale);
//});
}
WaitForAll(events.ToArray());
sw.Stop();
Console.WriteLine("本次產檔數量" + fileCounter);
Console.WriteLine($"花費時間: {sw.ElapsedMilliseconds} ms");
}