Windows phone 7 WP7 Silverlight应用程序中的计数器

我正在用c#silverlight编写扫雷游戏。
1.如何将计数器（仅计数秒）添加到此应用程序？
2.当应用程序转到后台（中间按钮、搜索按钮、来电等）时，如何停止计数器？
3.当WP7关闭我的申请过程时，我该如何做？例如，将当前游戏保存到独立存储。

1）您需要使用

2） 您需要处理OnNavigatedFrom事件：

private void Application_Deactivated(object sender, DeactivatedEventArgs e)
{
    //Do something
}

3） 这里有4个有用的事件：

    // Code to execute when the application is launching (eg, from Start)
// This code will not execute when the application is reactivated
private void Application_Launching(object sender, LaunchingEventArgs e)
{
    //Do something
}

// Code to execute when the application is activated (brought to foreground)
// This code will not execute when the application is first launched
private void Application_Activated(object sender, ActivatedEventArgs e)
{
    //Do something
}

// Code to execute when the application is deactivated (sent to background)
// This code will not execute when the application is closing
private void Application_Deactivated(object sender, DeactivatedEventArgs e)
{
    //Do something
}

// Code to execute when the application is closing (eg, user hit Back)
// This code will not execute when the application is deactivated
private void Application_Closing(object sender, ClosingEventArgs e)
{
    //Do something
}

在此处，您可以阅读有关处理此事件的更多信息：

    // Code to execute when the application is launching (eg, from Start)
// This code will not execute when the application is reactivated
private void Application_Launching(object sender, LaunchingEventArgs e)
{
    //Do something
}

// Code to execute when the application is activated (brought to foreground)
// This code will not execute when the application is first launched
private void Application_Activated(object sender, ActivatedEventArgs e)
{
    //Do something
}

// Code to execute when the application is deactivated (sent to background)
// This code will not execute when the application is closing
private void Application_Deactivated(object sender, DeactivatedEventArgs e)
{
    //Do something
}

// Code to execute when the application is closing (eg, user hit Back)
// This code will not execute when the application is deactivated
private void Application_Closing(object sender, ClosingEventArgs e)
{
    //Do something
}