微软UWP应用，导航栏设计。

Posted 2021-11-26 dddyg

实现两个页面之间的导航

重要的 API：Windows.UI.Xaml.Controls.Frame 类， Windows.UI.Xaml.Controls.Page 类 Windows.UI.Xaml.Navigation命名空间

在C#的通用桌面应用中加入2个空白页面：Page1，Page2.

<Grid>
        <TextBlock x:Name="pageTitle" Text="Page1" />
        <StackPanel>
            <TextBlock HorizontalAlignment="Center" Text="Enter your name"/>
            <TextBox HorizontalAlignment="Center" Width="200" Name="name"/>
            <HyperlinkButton Content="Click to go to page 2" 
                     Click="HyperlinkButton_Click"
                     HorizontalAlignment="Center" RenderTransformOrigin="0.475,3.859" VerticalAlignment="Center"/>
        </StackPanel>
 </Grid>

在Page1.xaml中加入HyperlinkButton元素，添加Click事件转至Page2。

<Grid>
        <TextBlock x:Name="pageTitle" Text="Page2" />
        <StackPanel>
            <TextBlock HorizontalAlignment="Center" Name="greeting"/>
            <HyperlinkButton Content="Click to go to page 1" 
                     Click="HyperlinkButton_Click"
                     HorizontalAlignment="Center"/>
        </StackPanel>
        <Button x:Name="BackButton" VerticalAlignment="Top" HorizontalAlignment="Left" Click="Back_Click" Style="{StaticResource NavigationBackButtonNormalStyle}"/>
 </Grid>

public sealed partial class Page1 : Page
    {
        public Page1()
        {
            this.InitializeComponent();
            this.NavigationCacheMode = Windows.UI.Xaml.Navigation.NavigationCacheMode.Enabled;
        }

        private void HyperlinkButton_Click(object sender, RoutedEventArgs e)
        {
            this.Frame.Navigate(typeof(Page2), name.Text);
        }
    }

 public sealed partial class Page2 : Page
    {
        public Page2()
        {
            this.InitializeComponent();
        }

        private void HyperlinkButton_Click(object sender, RoutedEventArgs e)
        {
            this.Frame.Navigate(typeof(Page1));
        }

        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            BackButton.IsEnabled = this.Frame.CanGoBack;
            if (e.Parameter is string && !string.IsNullOrWhiteSpace((string)e.Parameter))
            {
                greeting.Text = $"Hi, {e.Parameter.ToString()}";
            }
            else
            {
                greeting.Text = "Hi!";
            }
            base.OnNavigatedTo(e);
        }

        private void Back_Click(object sender, RoutedEventArgs e)
        {
            On_BackRequested();
        }

        // Handles system-level BackRequested events and page-level back button Click events
        private bool On_BackRequested()
        {
            if (this.Frame.CanGoBack)
            {
                this.Frame.GoBack();
                return true;
            }
            return false;
        }

        private void BackInvoked(KeyboardAccelerator sender, KeyboardAcceleratorInvokedEventArgs args)
        {
            On_BackRequested();
            args.Handled = true;
        }
    }

App.xaml.cs代码如下：

sealed partial class App : Application
    {
        /// <summary>
        /// 初始化单一实例应用程序对象。这是执行的创作代码的第一行，
        /// 已执行，逻辑上等同于 main() 或 WinMain()。
        /// </summary>
        public App()
        {
            this.InitializeComponent();
            this.Suspending += OnSuspending;
        }
       
        /// <summary>
        /// 在应用程序由最终用户正常启动时进行调用。
        /// 将在启动应用程序以打开特定文件等情况下使用。
        /// </summary>
        /// <param name="e">有关启动请求和过程的详细信息。</param>
        protected override void OnLaunched(LaunchActivatedEventArgs e)
        {
            Frame rootFrame = Window.Current.Content as Frame;

            // 不要在窗口已包含内容时重复应用程序初始化，
            // 只需确保窗口处于活动状态
            if (rootFrame == null)
            {
                // 创建要充当导航上下文的框架，并导航到第一页
                rootFrame = new Frame();

                rootFrame.NavigationFailed += OnNavigationFailed;

                if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
                {
                    //TODO: 从之前挂起的应用程序加载状态
                }

                // 将框架放在当前窗口中
                Window.Current.Content = rootFrame;
            }

            if (e.PrelaunchActivated == false)
            {
                if (rootFrame.Content == null)
                {
                    // 当导航堆栈尚未还原时，导航到第一页，
                    // 并通过将所需信息作为导航参数传入来配置
                    // 参数
                    rootFrame.Navigate(typeof(Page1), e.Arguments);
                }
                // 确保当前窗口处于活动状态
                Window.Current.Activate();
            }
        }

        /// <summary>
        /// 导航到特定页失败时调用
        /// </summary>
        ///<param name="sender">导航失败的框架</param>
        ///<param name="e">有关导航失败的详细信息</param>
        void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
        }

        /// <summary>
        /// 在将要挂起应用程序执行时调用。  在不知道应用程序
        /// 无需知道应用程序会被终止还是会恢复，
        /// 并让内存内容保持不变。
        /// </summary>
        /// <param name="sender">挂起的请求的源。</param>
        /// <param name="e">有关挂起请求的详细信息。</param>
        private void OnSuspending(object sender, SuspendingEventArgs e)
        {
            var deferral = e.SuspendingOperation.GetDeferral();
            //TODO: 保存应用程序状态并停止任何后台活动
            deferral.Complete();
        }
    }

运行结果：