wp8.1 app退出操作提示

微软的wp8.1 sdk相比之前wp8 sdk以及相关dll类库，微软又重新编译过，相关系统类库也经过精简，删改了部分传统dll库中的方法对象，很多常用方法对象被写进Windows.UI为前缀的命名空间中，可以看出微软wp8.1经过了一定的优化。

 

此处功能设计描述为，触摸一次返回键，提示是否退出app，再点一次即关闭app。

1 <Grid Background="#F5F5F5" DataContext="{Binding Path=MainPageViewModel, Source={StaticResource Locator}}">

2     <Grid Canvas.ZIndex="10000" Visibility="{Binding ExitNotificationVisible}" Height="30" Background="Red" VerticalAlignment="Top">

3         <TextBlock FontSize="14" Text="提示: 再按一次返回键退出支付宝" VerticalAlignment="Center" Margin="10 0 0 0" />

4     </Grid>

5     <ContentControl HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" Content="{Binding DynamicContent}" />

6 </Grid>

 

1 using System;

2 using Windows.UI.Xaml;

3 using Windows.UI.Xaml.Controls;

4 using Windows.UI.Popups;

 

 1 public class MainPageViewModel : Core.ViewModelBase

 2 {

 3     public MainPageViewModel()

 4     {

 5         InitData();

 6         if(DynamicContent == null)

 7         {

 8             DynamicContent = ViewControlLocator.Instance.RegisterViewControl<HomePage, HomePageViewModel>(true);

 9         }

10         //---物理返回键api---

11         Windows.Phone.UI.Input.HardwareButtons.BackPressed += HardwareButtons_BackPressed;

12     }

13 

14     #region  attribute

15     //---计时器---

16     DispatcherTimer timer = null;

17     int timesToTick = 2;

18 

19     private UserControl m_DynamicContent;

20     public UserControl DynamicContent

21     {

22         get { return m_DynamicContent; }

23         set { m_DynamicContent = value; RaisePropertyChanged("DynamicContent"); }

24     }

25 

26     private Visibility m_ExitNotificationVisible;

27     public Visibility ExitNotificationVisible

28     {

29         get { return m_ExitNotificationVisible; }

30         set { m_ExitNotificationVisible = value; RaisePropertyChanged("ExitNotificationVisible"); }

31     }

32     #endregion

33     

34     #region  method

35     private void InitData()

36     {

37         ExitNotificationVisible = Visibility.Collapsed;

38     }

39 

40     //---关闭事件---

41     void HardwareButtons_BackPressed(object sender, Windows.Phone.UI.Input.BackPressedEventArgs e)

42     {

43         e.Handled = true;

44         if (ExitNotificationVisible == Visibility.Collapsed)

45         {

46             ExitNotificationVisible = Visibility.Visible;

47 

48             if(timer == null)

49             {

50                 timer = new DispatcherTimer();

51             }                

52             timer.Interval = TimeSpan.FromSeconds(2);

53             timer.Tick += timer_Tick;

54             timer.Start();

55         }

56         else

57         {

58             App.Current.Exit();

59         }

60     }

61 

62     //---到时没有执行关闭操作，隐藏关闭操作提示---

63     void timer_Tick(object sender, object e)

64     {

65         timesToTick--;

66         if (timesToTick == 0)

67         {

68             timesToTick = 2;

69             timer.Tick -= timer_Tick;

70             timer.Stop();

71             ExitNotificationVisible = Visibility.Collapsed;  

72         }

73     }

74     #endregion

75 }