https://msdn.microsoft.com/zh-cn/library/dd460720.aspx
本示例显示如何使用 Parallel.ForEach 循环对任何 System.Collections.IEnumerable 或 System.Collections.Generic.IEnumerable<T> 数据源启用数据并行。
 注意 |
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本文档使用 lambda 表达式在 PLINQ 中定义委托。 如果您不熟悉 C# 或 Visual Basic 中的 lambda 表达式，请参见 Lambda Expressions in PLINQ and TPL。 |
示例
//
// IMPORTANT!!!: Add a reference to System.Drawing.dll
using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using System.Drawing;public class Example
{
public static void Main()
{
// 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)
// Be sure to add a reference to System.Drawing.dll.
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);
var bitmap = new Bitmap(currentFile); bitmap.RotateFlip(RotateFlipType.Rotate180FlipNone);
bitmap.Save(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 and method invocation
}); // Keep the console window open in debug mode.
Console.WriteLine("Processing complete. Press any key to exit.");
Console.ReadKey();
}
}
下面设置了最大的并发线程数
private static void TParllel()
{
var list = new List<int>(16000); for (int i = 0; i < 16000; i++)
{
list.Add(i);
}
Parallel.ForEach(list, new ParallelOptions { MaxDegreeOfParallelism = 200}, (p, state) => { Invoke(p); });
}
http://www.cnblogs.com/huangxincheng/archive/2012/04/02/2429543.html
