BackgroundTaskDeferral 类

定义

命名空间:

Windows.ApplicationModel.Background

表示 IBackgroundTaskInstance.GetDeferral 方法返回的后台任务延迟。

public ref class BackgroundTaskDeferral sealed

/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.MTA)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
class BackgroundTaskDeferral final

[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.MTA)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
public sealed class BackgroundTaskDeferral

Public NotInheritable Class BackgroundTaskDeferral

继承

Object Platform::Object IInspectable BackgroundTaskDeferral

属性

ContractVersionAttribute MarshalingBehaviorAttribute ThreadingAttribute

Windows 要求

设备系列	Windows 10 (在 10.0.10240.0 中引入)
API contract	Windows.Foundation.UniversalApiContract (在 v1.0 中引入)

示例

以下示例演示如何在异步代码仍在运行时使用后台任务延迟来延迟任务提前关闭。 确保完成所有后台任务延迟。 大多数后台任务都有一个超时，在此超时后，无论是否有任何挂起的延迟，应用都将暂停或终止。 但是，留下未完成的后台任务延迟会干扰系统及时管理进程生存期的能力。

//
// Declare that your background task's Run method makes asynchronous calls by
// using the async keyword.
//
public async void Run(IBackgroundTaskInstance taskInstance)
{
    //
    // Create the deferral by requesting it from the task instance.
    //
    BackgroundTaskDeferral deferral = taskInstance.GetDeferral();

    //
    // Call asynchronous method(s) using the await keyword.
    //
    var result = await ExampleMethodAsync();

    //
    // Once the asynchronous method(s) are done, close the deferral.
    //
    deferral.Complete();
}

方法

Complete()

通知系统与后台任务关联的异步操作已完成。