我知道 .net 4.5 有 await, async 关键字,可以轻松调用异步方法。我目前正在研究如何在 C# 4.0 中进行异步调用。我想要的一个例子是在数据网格被数据绑定的地方进行异步调用。
如果您能给我一些链接,我将不胜感激。
我知道 .net 4.5 有 await, async 关键字,可以轻松调用异步方法。我目前正在研究如何在 C# 4.0 中进行异步调用。我想要的一个例子是在数据网格被数据绑定的地方进行异步调用。
如果您能给我一些链接,我将不胜感激。
看看使用任务,这在 .Net 4 中可用,应该对您有所帮助。一个简单的示例可能如下所示:
public void MainFlow()
{
Task taskWork = Task.Factory.StartNew(new Action(DoWork));
//Do other work
//Then wait for thread finish
taskWork.Wait();
}
private void DoWork()
{
//Do work
}
更多,看这里
使用 Task.ContinueWith 在任务完成后基本上执行您的操作。
一些可能有用的例子:
我们制作了一些用于执行异步操作的工具类。
这些方法的真正作用是:异步执行操作,然后将完成的执行相应地发布到同步上下文。
我们将其作为 TPL 的包装器,以便在我们调用长时间运行的操作时在 WPF 中轻松使用它。这个类也有类似的动作可以取消,而不仅仅是放弃。
public static class AsyncExecutor
{
public static CancellationTokenSource ExecuteBlockingOperation(Action action, Action completition, Action<AggregateException> onException)
{
if (action == null)
throw new ArgumentNullException("action");
if (completition == null)
throw new ArgumentNullException("completition");
var cts = new CancellationTokenSource();
var token = cts.Token;
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task(action, TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (!token.IsCancellationRequested)
completition();
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
return cts;
}
public static CancellationTokenSource ExecuteBlockingOperation<TIn>(Action<TIn> action, TIn parameter, Action<TIn> completition, Action<AggregateException, TIn> onException)
{
if (action == null)
throw new ArgumentNullException("action");
if (completition == null)
throw new ArgumentNullException("completition");
var cts = new CancellationTokenSource();
var token = cts.Token;
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task(() => action(parameter), TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception, parameter), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (!token.IsCancellationRequested)
completition(parameter);
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
return cts;
}
public static CancellationTokenSource ExecuteBlockingOperation<TOut>(Func<TOut> func, Action<TOut> completition, Action<AggregateException> onException)
{
if (func == null)
throw new ArgumentNullException("func");
if (completition == null)
throw new ArgumentNullException("completition");
var cts = new CancellationTokenSource();
var token = cts.Token;
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task<TOut>(func, TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (!token.IsCancellationRequested)
completition(asyncPart.Result);
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
return cts;
}
public static CancellationTokenSource ExecuteBlockingOperation<TIn, TOut>(Func<TIn, TOut> func, TIn parameter, Action<TOut, TIn> completition, Action<AggregateException, TIn> onException)
{
if (func == null)
throw new ArgumentNullException("func");
if (completition == null)
throw new ArgumentNullException("completition");
var cts = new CancellationTokenSource();
var token = cts.Token;
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task<TOut>(() => func(parameter), TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception, parameter), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (!token.IsCancellationRequested)
completition(asyncPart.Result, parameter);
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
return cts;
}
public static CancellationTokenSource ExecuteBlockingOperation<TIn, TOut>(Func<TIn, TOut> func, TIn parameter, Action<TOut> completition, Action<AggregateException, TIn> onException)
{
if (func == null)
throw new ArgumentNullException("func");
if (completition == null)
throw new ArgumentNullException("completition");
var cts = new CancellationTokenSource();
var token = cts.Token;
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task<TOut>(() => func(parameter), TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception, parameter), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (!token.IsCancellationRequested)
completition(asyncPart.Result);
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
return cts;
}
public static CancellationTokenSource ExecuteBlockingOperation<TIn, TOut>(Func<TIn, TOut> func, TIn parameter, Action<TIn> completition, Action<AggregateException, TIn> onException)
{
if (func == null)
throw new ArgumentNullException("func");
if (completition == null)
throw new ArgumentNullException("completition");
var cts = new CancellationTokenSource();
var token = cts.Token;
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task<TOut>(() => func(parameter), TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception, parameter), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (!token.IsCancellationRequested)
completition(parameter);
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
return cts;
}
public static CancellationTokenSource ExecuteBlockingOperation<TIn, TOut>(Func<TIn, TOut> func, TIn parameter, Action completition, Action<AggregateException, TIn> onException)
{
if (func == null)
throw new ArgumentNullException("func");
if (completition == null)
throw new ArgumentNullException("completition");
var cts = new CancellationTokenSource();
var token = cts.Token;
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task<TOut>(() => func(parameter), TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception, parameter), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (!token.IsCancellationRequested)
completition();
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
return cts;
}
public static CancellationTokenSource ExecuteBlockingOperation<TIn, TOut>(Func<TIn, TOut> func, TIn parameter, Action<TIn> completition, Action<AggregateException> onException)
{
if (func == null)
throw new ArgumentNullException("func");
if (completition == null)
throw new ArgumentNullException("completition");
var cts = new CancellationTokenSource();
var token = cts.Token;
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task<TOut>(() => func(parameter), TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (!token.IsCancellationRequested)
completition(parameter);
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
return cts;
}
public static CancellationTokenSource ExecuteBlockingOperation<TIn, TOut>(Func<TIn, TOut> func, TIn parameter, Action<TOut, TIn> completition, Action<AggregateException> onException)
{
if (func == null)
throw new ArgumentNullException("func");
if (completition == null)
throw new ArgumentNullException("completition");
var cts = new CancellationTokenSource();
var token = cts.Token;
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task<TOut>(() => func(parameter), TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (!token.IsCancellationRequested)
completition(asyncPart.Result, parameter);
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
return cts;
}
public static CancellationTokenSource ExecuteBlockingOperation<TIn, TOut>(Func<TIn, TOut> func, TIn parameter, Action<TOut> completition, Action<AggregateException> onException)
{
if (func == null)
throw new ArgumentNullException("func");
if (completition == null)
throw new ArgumentNullException("completition");
var cts = new CancellationTokenSource();
var token = cts.Token;
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task<TOut>(() => func(parameter), TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (!token.IsCancellationRequested)
completition(asyncPart.Result);
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
return cts;
}
public static CancellationTokenSource ExecuteBlockingOperation<TIn, TOut>(Func<TIn, TOut> func, TIn parameter, Action completition, Action<AggregateException> onException)
{
if (func == null)
throw new ArgumentNullException("func");
if (completition == null)
throw new ArgumentNullException("completition");
var cts = new CancellationTokenSource();
var token = cts.Token;
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task<TOut>(() => func(parameter), TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (!token.IsCancellationRequested)
completition();
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
return cts;
}
public static void ExecuteBlockingOperation(Action action, Action completition, Func<bool> shouldComplete, Action<AggregateException> onException)
{
if (action == null)
throw new ArgumentNullException("action");
if (completition == null)
throw new ArgumentNullException("completition");
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task(action, TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (shouldComplete == null || shouldComplete())
completition();
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
}
public static void ExecuteBlockingOperation<TIn>(Action<TIn> action, TIn parameter, Action<TIn> completition, Predicate<TIn> shouldComplete, Action<AggregateException, TIn> onException)
{
if (action == null)
throw new ArgumentNullException("action");
if (completition == null)
throw new ArgumentNullException("completition");
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task(() => action(parameter), TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception, parameter), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPart =>
{
if (shouldComplete == null || shouldComplete(parameter))
completition(parameter);
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
}
public static void ExecuteBlockingOperation<TOut>(Func<TOut> func, Action<TOut> completition, Predicate<TOut> shoudComplete, Action<AggregateException> onException)
{
if (func == null)
throw new ArgumentNullException("func");
if (completition == null)
throw new ArgumentNullException("completition");
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task<TOut>(func, TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler);
task.ContinueWith(asyncPartTask =>
{
if (shoudComplete == null || shoudComplete(asyncPartTask.Result))
completition(asyncPartTask.Result);
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
}
public static void ExecuteBlockingOperation<TIn, TOut>(Func<TIn, TOut> func, TIn parameter, Action<TOut, TIn> completition, Func<TOut, TIn, bool> shouldComplete, Action<AggregateException, TIn> onException)
{
if (func == null)
throw new ArgumentNullException("func");
if (completition == null)
throw new ArgumentNullException("completition");
var scheduler = TaskScheduler.FromCurrentSynchronizationContext();
var task = new Task<TOut>(() => func(parameter), TaskCreationOptions.LongRunning);
task.ContinueWith(asyncPartTask => onException(asyncPartTask.Exception, parameter), CancellationToken.None, TaskContinuationOptions.OnlyOnFaulted, scheduler); // on Exception
task.ContinueWith(asyncPart =>
{
if (shouldComplete == null || shouldComplete(asyncPart.Result, parameter))
completition(asyncPart.Result, parameter);
},
CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, scheduler);
task.Start();
}
}