public abstract class TaskBase : PropertyChangeNotifier
{  //暂时省略了其他无关的代码public bool IsPause{get { return _isPause; } set { if (_isPause != value) { _isPause = value; if (value) { autoReset.Reset(); } else { autoReset.Set(); } OnPropertyChanged("IsPause"); } } } public bool CheckWait() { if (IsPause) { autoReset.WaitOne(); return true; } return false; } }

 foreach (var task in tasks){CheckWait();  //如果IsPause被设置True,此处自动阻塞action(task);  //执行对task的操作}

/// <summary>/// 任务调度器/// </summary>public class BatchTaskScheduler{public BatchTaskScheduler() { CurrentProcessTasks=new ObservableCollection<TaskBase>(); } /// <summary> /// 当前所有执行的任务 /// </summary> public IList<TaskBase> CurrentProcessTasks { get; set; } /// <summary> /// 添加一个临时任务 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="taskName">任务名称</param> /// <param name="enumable">任务枚举器</param> /// <param name="action">对枚举的每一个元素执行的操作</param> /// <param name="contineAction">枚举完成后执行的操作</param> /// <param name="count">可选，枚举总数量，用于指示进度条</param> /// <param name="autoStart">是否自动运行</param> public void AddTempTask<T>(string taskName, IEnumerable<T> enumable, Action<T> action, Action<int> contineAction = null, int count = -1, bool autoStart = true) { var tempTask = new TemporaryTask(); tempTask.Scheduler = this; tempTask.Name = taskName; tempTask.TaskAction = () => { if (enumable is ICollection<T>) { count = (enumable as ICollection<T>).Count; //此处可能能够获取整个枚举的大小  } if (count == 0) count = -1; var finish = false; foreach (var r in enumable) { if (action != null) action(r); tempTask.CheckWait(); if (r is int) { tempTask.CurrentIndex = Convert.ToInt32(r); } else { tempTask.CurrentIndex++; } if (count != -1) { tempTask.Percent = tempTask.CurrentIndex * 100 / count; //计算进度条位置  } if (tempTask.CheckCancel()) { finish = true; break; } } if (finish == true) tempTask.Percent = 100; if (contineAction != null) { ControlExtended.UIInvoke(() => contineAction(tempTask.CurrentIndex)); } }; this.CurrentProcessTasks.Add(tempTask); if (autoStart == true) { tempTask.Start(); } } }

public IEnumerable<int> TestTask(int count)  //表达一个耗时的函数
        {for (int j = 0; j < count; j++) { Thread.Sleep(300); yield return j; } } private void Button_Click_1(object sender, RoutedEventArgs e) { int total = 15;

    Scheduler.AddTempTask("任务1：延时测试", TestTask(total));  

     Scheduler.AddTempTask("任务1：延时测试", TestTask(total), null, result => MessageBox.Show(string.Format("延时测试任务已经完成,迭代位置{0}", result)), total);  }

 public IEnumerable<int> WriteFileUnsafe(string filename, int count){var fs = new FileStream(filename, FileMode.OpenOrCreate);var sw = new StreamWriter(new BufferedStream(fs), Encoding.Default); int j = 0;for (j = 0; j < count; j++) { Thread.Sleep(100); //模拟耗时任务 sw.WriteLine("这个数据是" + j); yield return j; } sw.Close(); fs.Close(); yield return j; }

   public class DisposeHelper : IDisposable{private Action action;public DisposeHelper(Action action2) { action = action2; } public void Dispose() { action(); } }

 public IEnumerable<int> WriteFileTask(string filename, int count){var fs = new FileStream(filename, FileMode.OpenOrCreate);var sw = new StreamWriter(new BufferedStream(fs), Encoding.Default); int j = 0; using (var dis = new DisposeHelper(() => { sw.Close(); fs.Close(); //不论是抛出异常，还是取消任务，还是正常完成，这段代码一定会被执行 })) { for (j = 0; j < count; j++) { Thread.Sleep(100); sw.WriteLine("这个数据是" + j); yield return j; } } }

 private void Button_Click_2(object sender, RoutedEventArgs e){string fileName = "Test.txt";Scheduler.AddTempTask("任务2：写入文件", WriteFileTask(fileName, 100), null, d => { Process.Start(fileName); }, 100); }

分类: 算法

本文转自FerventDesert博客园博客，原文链接：http://www.cnblogs.com/buptzym/p/4211768.html，如需转载请自行联系原作者