后台任务示例
这个示例显示了如何创建并注册后台任务使用Windows运行后台任务API。
一个后台任务是由于系统或时间事件,可以由一个或多个条件的限制。当一个后台任务被触发,其关联处理程序运行和执行任务的工作背景。一个后台任务可以运行一个应用程序,即使注册了后台任务被暂停。
这个示例演示了以下工作:
•创建和注册后台任务用c#编写的或JavaScript。
•创建一个后台任务,由系统事件触发。
•添加一个条件,限制后台任务运行只有当条件实际上是。
•报告后台任务进度和完成到前台应用程序。
•处理取消后台任务。
•初始化任务进程以及背景完成处理程序在启动应用程序时。
private void OnProgress(IBackgroundTaskRegistration sender, BackgroundTaskProgressEventArgs e)
{
//
// Update the UI with progress reported by the background task.
//
SampleDispatcher.InvokeAsync(CoreDispatcherPriority.Normal,
(task, args) =>
{
var taskRegistration = task as IBackgroundTaskRegistration;
var progressArgs = args.Context as BackgroundTaskProgressEventArgs;
if ((task != null) && (args != null))
{
switch (taskRegistration.Name)
{
case SampleBackgroundTaskName:
SampleBackgroundTaskProgress.Text = "Progress: " + progressArgs.Progress + "%";
break;
case SampleBackgroundTaskWithConditionName:
SampleBackgroundTaskWithConditionProgress.Text = "Progress: " + progressArgs.Progress + "%";
break;
case ServicingCompleteTaskName:
ServicingCompleteProgress.Text = "Progress: " + progressArgs.Progress + "%";
break;
case TimeTriggeredTaskName:
TimeTriggeredBackgroundTaskProgress.Text = "Progress: " + progressArgs.Progress + "%";
break;
}
}
},
sender,
e);
{
//
// Update the UI with progress reported by the background task.
//
SampleDispatcher.InvokeAsync(CoreDispatcherPriority.Normal,
(task, args) =>
{
var taskRegistration = task as IBackgroundTaskRegistration;
var progressArgs = args.Context as BackgroundTaskProgressEventArgs;
if ((task != null) && (args != null))
{
switch (taskRegistration.Name)
{
case SampleBackgroundTaskName:
SampleBackgroundTaskProgress.Text = "Progress: " + progressArgs.Progress + "%";
break;
case SampleBackgroundTaskWithConditionName:
SampleBackgroundTaskWithConditionProgress.Text = "Progress: " + progressArgs.Progress + "%";
break;
case ServicingCompleteTaskName:
ServicingCompleteProgress.Text = "Progress: " + progressArgs.Progress + "%";
break;
case TimeTriggeredTaskName:
TimeTriggeredBackgroundTaskProgress.Text = "Progress: " + progressArgs.Progress + "%";
break;
}
}
},
sender,
e);
}