static int shareData = 10;static void Main(string[] args){Parallel.For(1, 100000, i => Add(i));Console.Write(shareData);Console.ReadKey();}static void Add(int i){shareData += i;}

    class ParallerStudy{static int shareData = 10;static object lockObj = new object();static void Main(string[] args){Parallel.For(1, 100000, i => Add(i));Console.Write(shareData);Console.ReadKey();}static void Add(int i){lock (lockObj){shareData += i;}}}

    class ParallerStudy{static void Main(string[] args){var targetPath = $"{AppDomain.CurrentDomain.BaseDirectory}Test";var totalLength = DictionaryFilesContent(targetPath, "", SearchOption.TopDirectoryOnly);Console.WriteLine("{0}目录下所有的文件长度总和为:{1}", targetPath, totalLength);Console.ReadKey();}/// <summary>/// 多线程读取多个文件的内容/// </summary>/// <param name="i"></param>/// <returns></returns>static long DictionaryFilesContent(string path, string searchPattern, SearchOption searchOptions){var opts = new ParallelOptions();//只允许开六个线程去做这个事情opts.MaxDegreeOfParallelism =3;var files = Directory.EnumerateFiles(path);long totalFileLength = 0;Parallel.ForEach<string, long>(files,opts,//初始委托,该方法会在线程执行主要任务前执行,可用于参数校验等操作() =>{Console.WriteLine("开启读取文件,当前线程Id为{0}", Thread.CurrentThread.ManagedThreadId);return 0;},//主体委托,开始干正事(file, loopstate, index, taskLocalCount) =>{long fileLength = 0;FileStream fs = null;try{fs = File.OpenRead(file);fileLength = fs.Length;Console.WriteLine("当前线程Id为{1},当前文件名为{2}", index, Thread.CurrentThread.ManagedThreadId, fs.Name);}catch (IOException) { }//排除拒绝访问的文件finally{if (fs != null)fs.Dispose();}return taskLocalCount + fileLength;},//终结委托,一般用于汇总主体委托的结果值,所以如果这里涉及访问共享资源的话,一般会用同步构造,也就是加锁等操作taskLocalCount =>{//taskLocalCount=taskLocalCount + fileLength,单个文件的长度//同步构造,不需要加锁,当每个线程读取完对应文件的长度后,将长度加到totalFileLength中,这个时候多个线程访问这个变量可能会出现//多线程争用问题,但是使用Interlocked.Add相当与给totalFileLength加锁Interlocked.Add(ref totalFileLength, taskLocalCount);});return totalFileLength;}}

        static void Main(string[] args){var targetPath = $"{AppDomain.CurrentDomain.BaseDirectory}Test";var totalLength = DictionaryFilesContent(targetPath, "", SearchOption.TopDirectoryOnly);Console.WriteLine("{0}目录下所有的文件长度总和为:{1}", targetPath, totalLength);Console.ReadKey();}/// <summary>/// 多线程读取多个文件的内容/// </summary>/// <param name="i"></param>/// <returns></returns>static long DictionaryFilesContent(string path, string searchPattern, SearchOption searchOptions){var opts = new ParallelOptions();//只允许开六个线程去做这个事情opts.MaxDegreeOfParallelism =3;var files = Directory.EnumerateFiles(path);long totalFileLength = 0;Parallel.ForEach<string, long>(files,opts,//初始委托,该方法会在线程执行主要任务前执行,可用于参数校验等操作() =>{Console.WriteLine("开启读取文件,当前线程Id为{0}", Thread.CurrentThread.ManagedThreadId);return 0;},//主体委托,开始干正事(file, loopstate, index, taskLocalCount) =>{long fileLength = 0;FileStream fs = null;try{//处理完第3项,就不要在处理了,这个第三项的意思是不是第三个文件,也可能是第五个文件if (index == 3){loopstate.Stop();}fs = File.OpenRead(file);fileLength = fs.Length;Console.WriteLine("当前线程Id为{1},当前文件名为{2}", index, Thread.CurrentThread.ManagedThreadId, fs.Name);}catch (IOException) { }//排除拒绝访问的文件finally{if (fs != null)fs.Dispose();}return taskLocalCount + fileLength;},//终结委托,一般用于汇总主体委托的结果值,所以如果这里涉及访问共享资源的话,一般会用同步构造,也就是加锁等操作taskLocalCount =>{//taskLocalCount=taskLocalCount + fileLength,单个文件的长度//同步构造,不需要加锁,当每个线程读取完对应文件的长度后,将长度加到totalFileLength中,这个时候多个线程访问这个变量可能会出现//多线程争用问题,但是使用Interlocked.Add相当与给totalFileLength加锁Interlocked.Add(ref totalFileLength, taskLocalCount);});return totalFileLength;}