页面导航

在我们讲解如何使用Live Tile之前我们先仔细讲解讲解页面导航。

 

Windows Phone 应用程序基于 Silverlight 页面模型，用户可在其中向前导航以浏览不同屏幕的内容。此外，您也可以使用 Windows Phone 的“返回”硬件按键向后移动PhoneApplicationFrame是应用程序唯一的框架，PhoneApplicationPage是内容不同的页面,不同的页面之间需要进行导航。

 

 

导航一般有以下方式

一种是通过Xaml直接导航。

比如写下如下程序

        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
            <HyperlinkButton Content="SanFrancisco" Height="66" HorizontalAlignment="Left" Margin="6,6,0,0" Name="SanFrancisco" NavigateUri = "/PageSanfrancisco.xaml"
VerticalAlignment="Top" Width="200" />
        </Grid>

 

第二种是通过NavigationService， 在xaml文件里添加Button

     <Button Content="NewYork" Height="66" HorizontalAlignment="Left" Margin="12,62,0,0" Name="NewYork" VerticalAlignment="Top" Width="160" Click="NewYork_Click"/>

 

private void NewYork_Click(object sender, RoutedEventArgs e)
{
    this.NavigationService.Navigate(new Uri("/PageNewYork.xaml", UriKind.Relative));
}

NavigationService 有以下重要的Methods

GoBack	Navigates to the most recent entry in the back navigation history, or throws an exception if no entry exists in back navigation.
Navigate	Navigates to the content specified by the uniform resource identifier (URI).
StopLoading	Stops asynchronous navigations that have not yet been processed.

 

其中 GoForward在windows phone上面不受支持，CanGoForward在windows phone上一直都是FALSE, 调用此方法会收到InvalidOperationException. GoBack会回到历史上最新的条目，如果历史为空，可会收到异常。当页面之间切换的时候，OS不会把页面卸载或者销毁，所以当我们使用GoBack的方法时，只不过把页面重新显示，而当我们使用Navigate方法的时候,silverlight会在后台创建一个新的页面。

 

和五个重要的Event

FragmentNavigation	Occurs when navigation to a content fragment begins.
Navigated	Occurs when the content that is being navigated to has been found and is available.
Navigating	Occurs when a new navigation is requested.
NavigationFailed	Occurs when an error is encountered while navigating to the requested content.
NavigationStopped	Occurs when the StopLoading method is called, or when a new navigation is requested while the current navigation is in progress.