DispatcherQueue.ShutdownStarting 事件

定义

命名空间:

Windows.System

调用 ShutdownQueueAsync 时引发。 有关引发的事件的完整列表和顺序，请参阅 ShutdownQueueAsync 的备注。

// Register
event_token ShutdownStarting(TypedEventHandler<DispatcherQueue, DispatcherQueueShutdownStartingEventArgs const&> const& handler) const;

// Revoke with event_token
void ShutdownStarting(event_token const* cookie) const;

// Revoke with event_revoker
DispatcherQueue::ShutdownStarting_revoker ShutdownStarting(auto_revoke_t, TypedEventHandler<DispatcherQueue, DispatcherQueueShutdownStartingEventArgs const&> const& handler) const;

public event TypedEventHandler<DispatcherQueue,DispatcherQueueShutdownStartingEventArgs> ShutdownStarting;

function onShutdownStarting(eventArgs) { /* Your code */ }
dispatcherQueue.addEventListener("shutdownstarting", onShutdownStarting);
dispatcherQueue.removeEventListener("shutdownstarting", onShutdownStarting);
- or -
dispatcherQueue.onshutdownstarting = onShutdownStarting;

Public Custom Event ShutdownStarting As TypedEventHandler(Of DispatcherQueue, DispatcherQueueShutdownStartingEventArgs) 

事件类型

TypedEventHandler<DispatcherQueue,DispatcherQueueShutdownStartingEventArgs>

示例

_dispatcherQueue.ShutdownStarting += (s, e) =>
{
    // Queue is shutting down, do this last operation to  
    // update state before the dispatcher loop exits
    _queue.TryEnqueue(
        () =>
        {
            // clean up state
        });
};

注解

ShutdownStarting 事件在事件循环退出之前从事件循环线程引发。 此事件的处理程序可以采用延迟，并且可以继续发布工作，直到延迟完成。 延迟完成后， DispatcherQueue 不再接受工作， DispatcherQueue.TryEnqueue 返回 false。

另请参阅

• ShutdownQueueAsync()
• TryEnqueue(DispatcherQueueHandler)