wp8.1 边开发边学习记录

1. 拦截后退按钮

Protected Overrides Sub OnNavigatedTo(e As Navigation.NavigationEventArgs)
AddHandler HardwareButtons.BackPressed, AddressOf MainPage_BackPressed
End Sub

Protected Overrides Sub OnNavigatedFrom(e As NavigationEventArgs)
RemoveHandler HardwareButtons.BackPressed, AddressOf MainPage_BackPressed
End Sub

Private Sub MainPage_BackPressed(sender As Object, e As BackPressedEventArgs)
e.Handled = True
//todo
End Sub

2. 程序退出

Application.Current.Exit()

3.系统自带json

Imports Windows.Data.Json

4.保留页面缓存

Public Sub New()

' This call is required by the designer.
InitializeComponent()

' Add any initialization after the InitializeComponent() call.
Me.NavigationCacheMode = Navigation.NavigationCacheMode.Required
End Sub

5.httpclient不读缓存

Dim http As New HttpClient()
http.DefaultRequestHeaders.Add("Cache-Control", "no-cache")

6.计时器-1

Dim WithEvents dt As DispatcherTimer = New DispatcherTimer()
Private Sub dt_Tick(sender As Object, e As Object) Handles dt.Tick
'todo
End Sub