cyb*_*nic 3 c# navigationview uwp
我正在尝试制作一个UWP应用程序NavigationView
.我的问题是找到一种方法来Header
改变当前显示的页面.我的应用程序基于Microsoft UWP示例"AppUIBasics".在示例Header
中,NavigationView
节目总是"欢迎",因为它的硬编码但我希望它根据所选页面进行更改.
MainPage.xaml:
<NavigationView x:Name="NavView"
ItemInvoked="NavView_ItemInvoked"
SelectionChanged="NavView_SelectionChanged"
Loaded="NavView_Loaded"
Canvas.ZIndex="0">
<NavigationView.HeaderTemplate>
<DataTemplate>
<Grid Margin="24,10,0,0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBlock x:Name="appTitle" Style="{StaticResource TitleTextBlockStyle}"
FontSize="28"
VerticalAlignment="Center"
Text="Welcome"/>
<CommandBar Grid.Column="1"
HorizontalAlignment="Right"
VerticalAlignment="Top"
DefaultLabelPosition="Right"
Background="{ThemeResource SystemControlBackgroundAltHighBrush}">
<AppBarButton Label="Refresh" Icon="Refresh"/>
<AppBarButton Label="Import" Icon="Import"/>
</CommandBar>
</Grid>
</DataTemplate>
</NavigationView.HeaderTemplate>
<NavigationView.MenuItems>
<NavigationViewItem x:Uid="HomeNavItem" Content="" Tag="home">
<NavigationViewItem.Icon>
<FontIcon Glyph=""/>
</NavigationViewItem.Icon>
</NavigationViewItem>
<NavigationViewItemSeparator/>
<NavigationViewItem x:Uid="ConnectionNavItem" Icon="world" Content="" Tag="connection"/>
<NavigationViewItem x:Uid="CameraNavItem" Icon="video" Content="" Tag="camera"/>
</NavigationView.MenuItems>
<Frame x:Name="rootFrame" Margin="24">
<Frame.ContentTransitions>
<TransitionCollection>
<NavigationThemeTransition/>
</TransitionCollection>
</Frame.ContentTransitions>
</Frame>
</NavigationView>
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MainPage.xaml.cs:
public sealed partial class MainPage : Page {
public static MainPage Current;
public static Frame RootFrame = null;
//private RootFrameNavigationHelper _navHelper;
private ResourceLoader _resourceLoader = Windows.ApplicationModel.Resources.ResourceLoader.GetForCurrentView();
public MainPage() {
this.InitializeComponent();
this.Loaded += (sender, args) => {
Current = this;
var titleBar = Windows.ApplicationModel.Core.CoreApplication.GetCurrentView().TitleBar;
};
}
public Frame AppFrame { get { return this.rootFrame; } }
private void NavView_Loaded(object sender, RoutedEventArgs e) {
// set the initial SelectedItem
foreach (NavigationViewItemBase item in NavView.MenuItems) {
if (item is NavigationViewItem && item.Tag.ToString() == "home") {
NavView.SelectedItem = item;
break;
}
}
}
private void NavView_ItemInvoked(NavigationView sender, NavigationViewItemInvokedEventArgs args) {
if (args.IsSettingsInvoked) {
rootFrame.Navigate(typeof(SettingsPage));
} else {
// find NavigationViewItem with Content that equals InvokedItem
var item = sender.MenuItems.OfType<NavigationViewItem>().First(x => (string)x.Content == (string)args.InvokedItem);
NavView_Navigate(item as NavigationViewItem);
}
}
private void NavView_SelectionChanged(NavigationView sender, NavigationViewSelectionChangedEventArgs args) {
if (args.IsSettingsSelected) {
rootFrame.Navigate(typeof(SettingsPage));
} else {
NavigationViewItem item = args.SelectedItem as NavigationViewItem;
NavView_Navigate(item);
}
}
private void NavView_Navigate(NavigationViewItem item) {
switch (item.Tag) {
case "home":
rootFrame.Navigate(typeof(HomePage)); break;
case "connection":
rootFrame.Navigate(typeof(ConnectionPage)); break;
case "camera":
rootFrame.Navigate(typeof(CameraPage)); break;
}
}
}
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首先你要"非硬编码"从模板标题文本,相反,你可以使用文本的{Binding}
,这将提供分配给该值NavigationView
的Header
属性:
<NavigationView.HeaderTemplate>
<DataTemplate>
<Grid Margin="24,10,0,0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBlock x:Name="appTitle" Style="{StaticResource TitleTextBlockStyle}"
FontSize="28"
VerticalAlignment="Center"
Text="{Binding}"/>
<CommandBar Grid.Column="1"
HorizontalAlignment="Right"
VerticalAlignment="Top"
DefaultLabelPosition="Right"
Background="{ThemeResource SystemControlBackgroundAltHighBrush}">
<AppBarButton Label="Refresh" Icon="Refresh"/>
<AppBarButton Label="Import" Icon="Import"/>
</CommandBar>
</Grid>
</DataTemplate>
</NavigationView.HeaderTemplate>
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现在有两个地方可以设置标题内容.首先是SelectionChanged
事件:
private void NavView_SelectionChanged(NavigationView sender, NavigationViewSelectionChangedEventArgs args)
{
if (args.IsSettingsSelected)
{
rootFrame.Navigate(typeof(SettingsPage));
NavView.Header = "Settings";
}
else
{
NavigationViewItem item = args.SelectedItem as NavigationViewItem;
NavView_Navigate(item);
//just example, maybe you want to Content or something else
NavView.Header = item.Tag.ToString();
}
}
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您还Header
可以通过添加设置标头的公共方法来设置任意位置:
public void SetHeader(string header)
{
NavView.Header = header;
}
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然后使用MainPage.Current.SetHeader( something )
你认为合适的任何地方.
然而,最好的解决方案是创建一个基类,其他页面将派生自:
public class BasePage : Page
{
public virtual string Header => "";
}
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然后每个具体的页面都可以覆盖此属性:
public sealed partial class HomePage : BasePage
{
public override string Header => "Home";
public HomePage()
{
this.InitializeComponent();
}
}
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注意 - 请记住,您还必须在XAML中更新页面的基本类型:
<local:BasePage xmlns:local="using:AppNamespace"
x:Class="AppNamespace.HomePage" ...>
</local:BasePage>
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然后MainPage
我们使用数据绑定将Header
属性绑定到NavigationView
's Header
:
<NavigationView x:Name="NavView"
Header="{Binding Path=Content.Header, ElementName=rootFrame}" ...>
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