我是c＃中并行编程和tpl的新手，我正在进行以下测试，以了解任务的工作原理。每次单击button1并触发有界方法时，都会启动一个新任务。当我单击button_2时，所有任务都将退出循环，我将获得所有任务和任务ID的时间。
那么有没有办法在他们在任务池中工作时监视这些任务，所以如果我希望单独使用任务ID，我可以阻止它们吗？
Boolean stopprogramm = false;
private void button1_Click(object sender, EventArgs e)
{
Task timerTask1 = Task.Factory.StartNew(() =>
{
Stopwatch watch = new Stopwatch();
watch.Start();
while (stopprogramm == false)
{
//Do some work
}
Console.WriteLine("time ellapsed for No partitioning at all version {0}ms , thread id was {1}", watch.ElapsedMilliseconds, Task.CurrentId);
watch.Stop();
});
}
private void button2_Click(object sender, EventArgs e)
{
stopprogramm = true;
}
答案 0 :(得分：1)
这样的事情可行。
private Dictionary<Guid, TaskTracker> _taskMap = new Dictionary<Guid, TaskTracker>();
private void OnButton1Click(object sender, EventArgs eventArgs)
{
TaskTracker taskTracker = new TaskTracker(Guid.NewGuid(), OnDoWork);
_taskMap.Add(taskTracker.Identity, taskTracker);
taskTracker.Run();
}
private void OnDoWork()
{
// Do some work
}
private void OnButton2Click(object sender, EventArgs eventArgs)
{
Guid identity = _taskMap.Count > 0 ? _taskMap.First().Value.Identity : default(Guid); // find some way to get the desired task
TaskTracker taskTracker;
if (_taskMap.TryGetValue(identity, out taskTracker))
{
taskTracker.TaskExiting += OnTaskExiting;
taskTracker.Stop();
}
}
private void OnTaskExiting(object sender, EventArgs eventArgs)
{
TaskTracker taskTracker = (TaskTracker)sender;
taskTracker.TaskExiting -= OnTaskExiting;
_taskMap.Remove(taskTracker.Identity);
// do what you want with the timings
}
任务的课程是这样的：
public class TaskTracker
{
private readonly Action OnDoWork;
private Task _task;
private bool _isRunning = true;
public TaskTracker(Guid identity, Action onDoWork)
{
Identity = identity;
OnDoWork = onDoWork;
}
public readonly Guid Identity;
public readonly Stopwatch Stopwatch = new Stopwatch();
public event EventHandler TaskExiting;
public void Run()
{
Task _task = Task.Factory.StartNew(
() =>
{
Stopwatch.Start();
try
{
while (_isRunning)
{
OnDoWork();
}
if (TaskExiting != null)
{
TaskExiting(this, EventArgs.Empty);
}
}
finally
{
Stopwatch.Stop();
}
}
);
}
public void Stop()
{
_isRunning = false;
// wait for task to exit?
_task = null;
}
}
您需要填写空白，意味着跟踪任务并在按下按钮2时获取目标任务。
答案 1 :(得分：1)
您在我的其他答案中的一条评论中提到了一个链接，看起来该链接描述了如何使其取消。我已经调整了我的例子来支持这个：
private Dictionary<Guid, TaskTracker> _taskMap = new Dictionary<Guid, TaskTracker>();
private void OnButton1Click(object sender, EventArgs eventArgs)
{
TaskTracker taskTracker = new TaskTracker(Guid.NewGuid(), OnDoWork);
_taskMap.Add(taskTracker.Identity, taskTracker);
taskTracker.Start();
}
private void OnDoWork(CancellationToken token)
{
for (int i = 0; i < 100; i++)
{
Thread.Sleep(100); // Do some work, checking if cancel requested every once in a while
if (token.IsCancellationRequested)
{
token.ThrowIfCancellationRequested();
}
}
}
private void OnButton2Click(object sender, EventArgs eventArgs)
{
Guid identity = _taskMap.Count > 0 ? _taskMap.First().Value.Identity : default(Guid); // find some way to get the desired task
TaskTracker taskTracker;
if (_taskMap.TryGetValue(identity, out taskTracker))
{
taskTracker.TaskExiting += OnTaskExiting;
taskTracker.Stop();
}
}
private void OnTaskExiting(object sender, EventArgs eventArgs)
{
TaskTracker taskTracker = (TaskTracker)sender;
taskTracker.TaskExiting -= OnTaskExiting;
_taskMap.Remove(taskTracker.Identity);
Console.WriteLine("Time ellapsed for No partitioning at all version {0}ms , thread id was {1}", taskTracker.Stopwatch.ElapsedMilliseconds, Task.CurrentId);
}
private void OnButton3Click(object sender, EventArgs eventArgs)
{
Guid identity = _taskMap.Count > 0 ? _taskMap.First().Value.Identity : default(Guid); // find some way to get the desired task
TaskTracker taskTracker;
if (_taskMap.TryGetValue(identity, out taskTracker))
{
taskTracker.TaskExiting += OnTaskExiting;
taskTracker.Cancel();
}
}
这是TaskTracker类：
public class TaskTracker
{
private readonly Action<CancellationToken> OnDoWork;
private readonly CancellationTokenSource TokenSource;
private readonly CancellationToken Token;
private bool _isRunning;
private Task _task;
public TaskTracker(Guid identity, Action<CancellationToken> onDoWork)
{
TokenSource = new CancellationTokenSource();
Token = TokenSource.Token;
Identity = identity;
OnDoWork = onDoWork;
}
public readonly Guid Identity;
public readonly Stopwatch Stopwatch = new Stopwatch();
public event EventHandler TaskExiting;
public void Start()
{
_isRunning = true;
_task = Task.Factory.StartNew(
() =>
{
Stopwatch.Start();
try
{
while (_isRunning)
{
OnDoWork(Token);
}
}
finally
{
Stopwatch.Stop();
if (TaskExiting != null)
{
TaskExiting(this, EventArgs.Empty);
}
}
}, Token
);
}
public void Stop(bool waitForTaskToExit = false)
{
if (_task == null)
{
throw new InvalidOperationException("Task hasn't been started yet");
}
_isRunning = false;
if (waitForTaskToExit)
{
_task.Wait();
}
_task = null;
}
public void Cancel()
{
if (_task == null)
{
throw new InvalidOperationException("Task hasn't been started yet");
}
_isRunning = false;
TokenSource.Cancel();
_task = null;
}
}
基本上，在你的“工作者”中，你会检查令牌是否表明它被取消，如果是，那么做一些清理，然后调用令牌上的方法ThrowIfCancellationRequested来打破。