TaskStatus 枚举
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
表示 Task 的生命周期中的当前阶段。
public enum class TaskStatus
public enum TaskStatus
type TaskStatus =
Public Enum TaskStatus
- 继承
字段
Canceled | 6 | 该任务已通过对其自身的 CancellationToken 引发 OperationCanceledException 对取消进行了确认,此时该标记处于已发送信号状态;或者在该任务开始执行之前,已向该任务的 CancellationToken 发出了信号。 有关详细信息,请参阅任务取消。 |
Created | 0 | 该任务已初始化,但尚未被计划。 |
Faulted | 7 | 由于未处理异常的原因而完成的任务。 |
RanToCompletion | 5 | 已成功完成执行的任务。 |
Running | 3 | 该任务正在运行,但尚未完成。 |
WaitingForActivation | 1 | 该任务正在等待 .NET 基础结构在内部将其激活并进行计划。 |
WaitingForChildrenToComplete | 4 | 该任务已完成执行,正在隐式等待附加的子任务完成。 |
WaitingToRun | 2 | 该任务已被计划执行,但尚未开始执行。 |
示例
以下示例创建 20 个任务,这些任务将循环到计数器递增到值 200 万。 当前 10 个任务达到 200 万时,取消取消令牌,并且取消其计数器未达到 200 万的任务。 然后,该示例检查 Task.Status 每个任务的属性,以指示任务是否已成功完成或已取消。 对于已完成的值,它显示任务返回的值。
using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
public class Example
{
public static void Main()
{
var tasks = new List<Task<int>>();
var source = new CancellationTokenSource();
var token = source.Token;
int completedIterations = 0;
for (int n = 0; n <= 19; n++)
tasks.Add(Task.Run( () => { int iterations = 0;
for (int ctr = 1; ctr <= 2000000; ctr++) {
token.ThrowIfCancellationRequested();
iterations++;
}
Interlocked.Increment(ref completedIterations);
if (completedIterations >= 10)
source.Cancel();
return iterations; }, token));
Console.WriteLine("Waiting for the first 10 tasks to complete...\n");
try {
Task.WaitAll(tasks.ToArray());
}
catch (AggregateException) {
Console.WriteLine("Status of tasks:\n");
Console.WriteLine("{0,10} {1,20} {2,14:N0}", "Task Id",
"Status", "Iterations");
foreach (var t in tasks)
Console.WriteLine("{0,10} {1,20} {2,14}",
t.Id, t.Status,
t.Status != TaskStatus.Canceled ? t.Result.ToString("N0") : "n/a");
}
}
}
// The example displays output like the following:
// Waiting for the first 10 tasks to complete...
// Status of tasks:
//
// Task Id Status Iterations
// 1 RanToCompletion 2,000,000
// 2 RanToCompletion 2,000,000
// 3 RanToCompletion 2,000,000
// 4 RanToCompletion 2,000,000
// 5 RanToCompletion 2,000,000
// 6 RanToCompletion 2,000,000
// 7 RanToCompletion 2,000,000
// 8 RanToCompletion 2,000,000
// 9 RanToCompletion 2,000,000
// 10 Canceled n/a
// 11 Canceled n/a
// 12 Canceled n/a
// 13 Canceled n/a
// 14 Canceled n/a
// 15 Canceled n/a
// 16 RanToCompletion 2,000,000
// 17 Canceled n/a
// 18 Canceled n/a
// 19 Canceled n/a
// 20 Canceled n/a
Imports System.Collections.Generic
Imports System.Threading
Imports System.Threading.Tasks
Module Example
Public Sub Main()
Dim tasks As New List(Of Task(Of Integer))()
Dim source As New CancellationTokenSource
Dim token As CancellationToken = source.Token
Dim completedIterations As Integer = 0
For n As Integer = 0 To 19
tasks.Add(Task.Run( Function()
Dim iterations As Integer= 0
For ctr As Long = 1 To 2000000
token.ThrowIfCancellationRequested()
iterations += 1
Next
Interlocked.Increment(completedIterations)
If completedIterations >= 10 Then source.Cancel()
Return iterations
End Function, token))
Next
Console.WriteLine("Waiting for the first 10 tasks to complete... ")
Try
Task.WaitAll(tasks.ToArray())
Catch e As AggregateException
Console.WriteLine("Status of tasks:")
Console.WriteLine()
Console.WriteLine("{0,10} {1,20} {2,14}", "Task Id",
"Status", "Iterations")
For Each t In tasks
Console.WriteLine("{0,10} {1,20} {2,14}",
t.Id, t.Status,
If(t.Status <> TaskStatus.Canceled,
t.Result.ToString("N0"), "n/a"))
Next
End Try
End Sub
End Module
' The example displays output like the following:
' Waiting for the first 10 tasks to complete...
' Status of tasks:
'
' Task Id Status Iterations
' 1 RanToCompletion 2,000,000
' 2 RanToCompletion 2,000,000
' 3 RanToCompletion 2,000,000
' 4 RanToCompletion 2,000,000
' 5 RanToCompletion 2,000,000
' 6 RanToCompletion 2,000,000
' 7 RanToCompletion 2,000,000
' 8 RanToCompletion 2,000,000
' 9 RanToCompletion 2,000,000
' 10 Canceled n/a
' 11 Canceled n/a
' 12 Canceled n/a
' 13 Canceled n/a
' 14 Canceled n/a
' 15 Canceled n/a
' 16 RanToCompletion 2,000,000
' 17 Canceled n/a
' 18 Canceled n/a
' 19 Canceled n/a
' 20 Canceled n/a
注解
该 Task.Status 属性返回枚举的成员 TaskStatus ,以指示任务的当前状态。