使用 NavigationView 控件，如何從后面的代碼導航？

Question

是否可以從 NavigationView 中的代碼隱藏導航？ 如果我是 NavigationView 框架中的一頁，並且我想離開該頁面並顯示另一個有效頁面，這是否可能。 我的項目不是 MVVM 結構。 我感謝您的幫助。

這是我的導航視圖：

<NavigationView x:Name="MasterNavigation"
                Header="Main"
                ItemInvoked="MasterNavigation_ItemInvoked" 
                PaneTitle="Menu"
                IsBackButtonVisible="Collapsed"
                IsSettingsVisible="False"
                PaneDisplayMode="Auto"
                OpenPaneLength="200"
                IsTabStop="True">
    
    <NavigationView.MenuItems>

        <NavigationViewItem Icon="Home"       Content="Home"                 Tag="home" IsSelected="True"/>
        <NavigationViewItem Icon="Globe"      Content="Data Collection"      Tag="datacollection"/>
        <NavigationViewItem Icon="Globe"      Content="Data Collection (v2)" Tag="collectdata"/>
        <NavigationViewItem Icon="Document"   Content="Goals"                Tag="goals"/>
        <NavigationViewItem Icon="Manage"     Content="Approvals"            Tag="approvals"/>
        <NavigationViewItem Icon="Print"      Content="Reports"              Tag="reports"/>
        <NavigationViewItem Icon="Admin"      Content="Admin"                Tag="admin"/>
        <NavigationViewItem Icon="PostUpdate" Content="Metric Staging"       Tag="metricstaging"/>
        <NavigationViewItem Icon="PostUpdate" Content="Ref Metric Main"      Tag="refmetricmain"/>
        <!--<NavigationViewItem Icon="Calculator" Content="Dashboard" Tag="dashboard" />-->

    </NavigationView.MenuItems>
    
    <Frame x:Name="MasterContentFrame" Margin="0,0,0,0"/>

</NavigationView>

這是我用來通過 UI 導航的代碼：

        private void MasterNavigation_ItemInvoked(NavigationView sender, NavigationViewItemInvokedEventArgs args)
        {
            if (args.IsSettingsInvoked)
            {
                MasterContentFrame.Navigate(typeof(pageSettings));
            }
            else
            {
                // find NavigationViewItem with Content that equals InvokedItem
                NavigationViewItem item = sender.MenuItems.OfType<NavigationViewItem>().First(x => (string)x.Content == (string)args.InvokedItem);
                NavView_Navigate(item);
            }
        }

        private void NavView_Navigate(NavigationViewItem item)
        {
            switch (item.Tag)
            {
                case "home":
                    MasterContentFrame.Navigate(typeof(pageHome));
                    MasterNavigation.Header = item.Content;
                    break;

                case "datacollection":
                    MasterContentFrame.Navigate(typeof(pageDataCollection));
                    MasterNavigation.Header = item.Content;
                    break;

                case "collectdata":
                    MasterContentFrame.Navigate(typeof(PageCollectMetricData));
                    MasterNavigation.Header = item.Content;
                    break;

                case "goals":
                    MasterContentFrame.Navigate(typeof(pageGoals));
                    MasterNavigation.Header = item.Content;
                    break;

                case "approvals":
                    MasterContentFrame.Navigate(typeof(pageComments));
                    MasterNavigation.Header = item.Content;
                    break;

                case "reports":
                    MasterContentFrame.Navigate(typeof(pageReports));
                    MasterNavigation.Header = item.Content;
                    break;

                case "admin":
                    MasterContentFrame.Navigate(typeof(pageAdmin));
                    MasterNavigation.Header = item.Content;
                    break;

                case "metricstaging":
                    MasterContentFrame.Navigate(typeof(pageMetricStaging));
                    MasterNavigation.Header = item.Content;
                    break;

                case "refmetricmain":
                    MasterContentFrame.Navigate(typeof(pageRefMetricMain));
                    MasterNavigation.Header = item.Content;
                    break;
            }
        }

我在“Metric Staging”頁面上有一個按鈕，如果單擊該按鈕，我希望它在 MasterContentFrame 中打開“Data Collection”頁面。

這是按鈕事件代碼，當在“Metric Staging”頁面上單擊按鈕時觸發：

private void ButtonListViewEdit_Click(object sender, RoutedEventArgs e)
{
    Debug.WriteLine($"PAGE METRIC STAGING: BUTTON WAS CLICKED");
    // Below are my attempts to implement 'code-behind' navigation 
    //MetricReporting.MainWindow MasterContentFrame.Navigate(typeof(pageDataCollection));
    //MasterNavigation.Header = "Data Collection";
    //var navigation = (Application.Current as App).MasterNavigation;
}

Answer 1

您可以將 window 中Frame元素的x:FieldModifier屬性設置為internal或public ，以便能夠從另一個 class 訪問該Frame ：

<Frame x:Name="MasterContentFrame" x:FieldModifier="internal" Margin="0,0,0,0"/>

同時更改 App.xaml.cs 中m_window字段的App.xaml.cs ：

internal Window m_window;

然后，您可以從Page中的事件處理程序訪問Frame ，如下所示：

private void ButtonListViewEdit_Click(object sender, RoutedEventArgs e)
{
    MainWindow window = (App.Current as App)?.m_window as MainWindow;
    if (window != null)
    {
        window.MasterContentFrame.Navigate(typeof(typeof(pageDataCollection)));
    }
}