Windows Phone 7·動態改變Windows Phone 7的初始頁面

Windows Phone 7的預設頁面是在名叫WMAppManifest.xml檔案裡配置的
<Tasks>

<DefaultTask Name="_default" NavigationPage="LoginPage.xaml" />

</Tasks>

假如在啟動程式的時候根據狀態改變初始頁面，比如程式在啟動的時候判斷使用者是否登入，如果未登入則跳轉到LoginPage.xaml否則跳轉到其他介面。

代碼如下：
private void InitializePhoneApplication()
{
if (phoneApplicationInitialized)
{
return;
}
// Create the frame but don't set it as RootVisual yet; this allows the splash
// screen to remain active until the application is ready to render.
RootFrame = new PhoneApplicationFrame();
RootVisual = RootFrame;
RootFrame.Navigated += CompleteInitializePhoneApplication;
// Handle navigation failures
RootFrame.NavigationFailed += RootFrame_NavigationFailed;
RootFrame.Navigating += new NavigatingCancelEventHandler(RootFrame_Navigating);//加上Navigating的事件
// Ensure we don't initialize again
phoneApplicationInitialized = true;
}
void RootFrame_Navigating(object sender, NavigatingCancelEventArgs e)
{
if (e.Uri.ToString().Contains("LoginPage.xaml") && !Api.IsVerify)//這裡一定要有判斷條件，因為RootFrame在任何頁面進行Navigate的時候都會掉用Navigating，或者採用跟RootFrame.Navigated 方式一樣的遞迴方法
{
e.Cancel = true;//取消事件
string uriString = "/LoginPage.xaml";
Uri ur = new Uri(uriString, UriKind.Relative);
this.RootFrame.Dispatcher.BeginInvoke(delegate
{
this.RootFrame.Navigate(ur);
});
}
}