Я пытаюсь создать NavigationViewItem, который перемещается к двум различным представлениям в зависимости от условия.
Приложение UWP было создано с использованием Windows Template Studio и уже имеет функции NavigationView и функции по умолчанию. перемещаться между страницами. Я хочу, чтобы приложение проверило состояние, а затем либо перейти к одному или другому представлению, если пользователь нажимает NavigationViewItem. Кроме того, приложение должно сохранять цветную линию, указывающую, какой режим просмотра включен, на одной NavigationViewItem.
. Так выглядит мой NavigationView в данный момент. Я хотел бы объединить SetTimer и WatchTimer Views. Я, к сожалению, понятия не имею, как работает базовый код, так как он был сгенерирован автоматически, и я не совсем понимаю его.
<winui:NavigationView.MenuItems>
<winui:NavigationViewItem x:Uid="Shell_SetTimer" helpers:NavHelper.NavigateTo="views:SetTimerPage" />
<winui:NavigationViewItem x:Uid="Shell_WatchTimer" helpers:NavHelper.NavigateTo="views:WatchTimerPage" />
<winui:NavigationViewItem x:Uid="Shell_History" helpers:NavHelper.NavigateTo="views:HistoryPage" />
</winui:NavigationView.MenuItems>
Это код позади:
using System;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Threading.Tasks;
using ShutdownTimer.Helpers;
using ShutdownTimer.Services;
using Windows.System;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Navigation;
using WinUI = Microsoft.UI.Xaml.Controls;
namespace ShutdownTimer.Views
{
public sealed partial class ShellPage : Page, INotifyPropertyChanged
{
private readonly KeyboardAccelerator _altLeftKeyboardAccelerator = BuildKeyboardAccelerator(VirtualKey.Left, VirtualKeyModifiers.Menu);
private readonly KeyboardAccelerator _backKeyboardAccelerator = BuildKeyboardAccelerator(VirtualKey.GoBack);
private bool _isBackEnabled;
private WinUI.NavigationViewItem _selected;
public bool IsBackEnabled
{
get { return _isBackEnabled; }
set { Set(ref _isBackEnabled, value); }
}
public WinUI.NavigationViewItem Selected
{
get { return _selected; }
set { Set(ref _selected, value); }
}
public ShellPage()
{
InitializeComponent();
DataContext = this;
Initialize();
}
private void Initialize()
{
NavigationService.Frame = shellFrame;
NavigationService.NavigationFailed += Frame_NavigationFailed;
NavigationService.Navigated += Frame_Navigated;
navigationView.BackRequested += OnBackRequested;
}
private async void OnLoaded(object sender, RoutedEventArgs e)
{
// Keyboard accelerators are added here to avoid showing 'Alt + left' tooltip on the page.
// More info on tracking issue https://github.com/Microsoft/microsoft-ui-xaml/issues/8
KeyboardAccelerators.Add(_altLeftKeyboardAccelerator);
KeyboardAccelerators.Add(_backKeyboardAccelerator);
await Task.CompletedTask;
}
private void Frame_NavigationFailed(object sender, NavigationFailedEventArgs e)
{
throw e.Exception;
}
private void Frame_Navigated(object sender, NavigationEventArgs e)
{
IsBackEnabled = NavigationService.CanGoBack;
if (e.SourcePageType == typeof(SettingsPage))
{
Selected = navigationView.SettingsItem as WinUI.NavigationViewItem;
return;
}
Selected = navigationView.MenuItems
.OfType<WinUI.NavigationViewItem>()
.FirstOrDefault(menuItem => IsMenuItemForPageType(menuItem, e.SourcePageType));
}
private bool IsMenuItemForPageType(WinUI.NavigationViewItem menuItem, Type sourcePageType)
{
var pageType = menuItem.GetValue(NavHelper.NavigateToProperty) as Type;
return pageType == sourcePageType;
}
private void OnItemInvoked(WinUI.NavigationView sender, WinUI.NavigationViewItemInvokedEventArgs args)
{
if (args.IsSettingsInvoked)
{
NavigationService.Navigate(typeof(SettingsPage));
return;
}
var item = navigationView.MenuItems
.OfType<WinUI.NavigationViewItem>()
.First(menuItem => (string)menuItem.Content == (string)args.InvokedItem);
var pageType = item.GetValue(NavHelper.NavigateToProperty) as Type;
NavigationService.Navigate(pageType);
}
private void OnBackRequested(WinUI.NavigationView sender, WinUI.NavigationViewBackRequestedEventArgs args)
{
NavigationService.GoBack();
}
private static KeyboardAccelerator BuildKeyboardAccelerator(VirtualKey key, VirtualKeyModifiers? modifiers = null)
{
var keyboardAccelerator = new KeyboardAccelerator() { Key = key };
if (modifiers.HasValue)
{
keyboardAccelerator.Modifiers = modifiers.Value;
}
keyboardAccelerator.Invoked += OnKeyboardAcceleratorInvoked;
return keyboardAccelerator;
}
private static void OnKeyboardAcceleratorInvoked(KeyboardAccelerator sender, KeyboardAcceleratorInvokedEventArgs args)
{
var result = NavigationService.GoBack();
args.Handled = result;
}
public event PropertyChangedEventHandler PropertyChanged;
private void Set<T>(ref T storage, T value, [CallerMemberName]string propertyName = null)
{
if (Equals(storage, value))
{
return;
}
storage = value;
OnPropertyChanged(propertyName);
}
private void OnPropertyChanged(string propertyName) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
NavHelper
using System;
using Microsoft.UI.Xaml.Controls;
using Windows.UI.Xaml;
namespace ShutdownTimer.Helpers
{
public class NavHelper
{
// This helper class allows to specify the page that will be shown when you click on a NavigationViewItem
//
// Usage in xaml:
// <winui:NavigationViewItem x:Uid="Shell_Main" Icon="Document" helpers:NavHelper.NavigateTo="views:MainPage" />
//
// Usage in code:
// NavHelper.SetNavigateTo(navigationViewItem, typeof(MainPage));
public static Type GetNavigateTo(NavigationViewItem item)
{
return (Type)item.GetValue(NavigateToProperty);
}
public static void SetNavigateTo(NavigationViewItem item, Type value)
{
item.SetValue(NavigateToProperty, value);
}
public static readonly DependencyProperty NavigateToProperty =
DependencyProperty.RegisterAttached("NavigateTo", typeof(Type), typeof(NavHelper), new PropertyMetadata(null));
}
}