如何将foreach转换为Parallel.foreach

本文关键字：foreach Parallel 转换 | 更新日期: 2023-09-27 17:58:49

如何转换：

  foreach (  NotifyCollectionChangedEventHandler handler in delegates) {
            ...
  }

像这样的

 Parallel.ForEach(    NotifyCollectionChangedEventHandler handler in delegates) {
  ... 
 }

如何将foreach转换为Parallel.foreach

你可以做：

Parallel.ForEach(delegates, handler => 
{ 
//your stuff 
});

考虑以下示例

List<string> list = new List<string>()
{
    "ABC",
    "DEF", 
    "EFG"
};
Parallel.ForEach(list, str =>
{
    Console.WriteLine(str);
});

您还可以看到：如何：为每个循环编写简单的并行程序

MSDN中的一个简单示例。 
  // A simple source for demonstration purposes. Modify this path as necessary. 
string[] files = System.IO.Directory.GetFiles(@"C:'Users'Public'Pictures'Sample Pictures", "*.jpg");
string newDir = @"C:'Users'Public'Pictures'Sample Pictures'Modified";
System.IO.Directory.CreateDirectory(newDir);
//  Method signature: Parallel.ForEach(IEnumerable<TSource> source, Action<TSource> body)
Parallel.ForEach(files, currentFile =>
{
    // The more computational work you do here, the greater  
    // the speedup compared to a sequential foreach loop. 
    string filename = System.IO.Path.GetFileName(currentFile);
    System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(currentFile);
    bitmap.RotateFlip(System.Drawing.RotateFlipType.Rotate180FlipNone);
    bitmap.Save(System.IO.Path.Combine(newDir, filename));
    // Peek behind the scenes to see how work is parallelized. 
    // But be aware: Thread contention for the Console slows down parallel loops!!!
    Console.WriteLine("Processing {0} on thread {1}", filename, Thread.CurrentThread.ManagedThreadId);
    } //close lambda expression
); //close method invocation

这里，很容易：

Parallel.ForEach(delegates, handler => 
                            {
                                 //Do your thing with the handler and may the thread-safety be with you.
                            });

尽管在阅读了这些文档后应该会很明显。

为您的目的添加一些Action<TSource>参数参数：

Parallel.ForEach(delegates, d => { ... });
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