WPF MVVM Page页面导航

这里一共添加三个界面进行演示，MainWindow.xaml，,

1，启动显示LoginView界面，点击按钮跳转到HomeView界面

2，点击HomeView界面按钮返回LoginView界面

需要安装的两个包：

1，

2，CommunityToolkit.Mvvm

<Window x:Class=""
        xmlns="/winfx/2006/xaml/presentation"
        xmlns:x="/winfx/2006/xaml"
        xmlns:d="/expression/blend/2008"
        xmlns:mc="/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp5"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Frame x:Name="MainFrame" Content="{Binding CurrentPage,Converter={local:ApplicationPageValueConverter}}" NavigationUIVisibility="Hidden"/>
    </Grid>
</Window>
 

 

 public partial class MainWindow : Window
    {
        public MainViewModel MainViewModel;
        public MainWindow()
        {
            InitializeComponent();
            MainViewModel = new MainViewModel();
            = MainViewModel;
            += MainWindow_Loaded;
        }

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

public partial class MainViewModel:BaseViewModel
    {
        public ApplicationPage CurrentPage { get; set; } = ;
    }

 

<Page x:Class=""
      xmlns="/winfx/2006/xaml/presentation"
      xmlns:x="/winfx/2006/xaml"
      xmlns:mc="/markup-compatibility/2006" 
      xmlns:d="/expression/blend/2008" 
      xmlns:local="clr-namespace:"
      mc:Ignorable="d" 
      d:DesignHeight="450" d:DesignWidth="800"
      Title="LoginView">

    <Grid>
        <Button Content="登录" Height="100" Width="100" Command="{Binding LoginCommand}"/>
    </Grid>
</Page>
 

 

 public partial class LoginView : Page
    {
        public LoginViewModel LoginViewModel;
        public LoginView()
        {
            InitializeComponent();
            LoginViewModel = new LoginViewModel();
            = LoginViewModel;
        }
    } 

 

using ;
using System.Windows.Input;

namespace WpfApp5
{
   public class LoginViewModel : BaseViewModel
    {
        public ICommand LoginCommand { get; set; }

        public LoginViewModel() 
        {
            LoginCommand = new RelayCommand(LoginCommandEvent);
        }

        private void LoginCommandEvent()
        {
            ();
        }
    }
}
 

<Page x:Class=""
      xmlns="/winfx/2006/xaml/presentation"
      xmlns:x="/winfx/2006/xaml"
      xmlns:mc="/markup-compatibility/2006" 
      xmlns:d="/expression/blend/2008" 
      xmlns:local="clr-namespace:"
      mc:Ignorable="d" 
      d:DesignHeight="450" d:DesignWidth="800"
      Title="HomeView">

    <Grid>
       <Button Content="返回登录界面" Height="100" Width="100" Command="{Binding HomeCommand}"/>
    </Grid>
</Page>
 

 

  public partial class HomeView : Page
    {
        public HomeViewModel homeViewModel;
        public HomeView()
        {
            InitializeComponent();
            homeViewModel = new HomeViewModel();
            = homeViewModel;
        }
    }

 public class HomeViewModel : BaseViewModel
    {
        public ICommand HomeCommand { get; set; }

        public HomeViewModel()
        {
            HomeCommand = new RelayCommand(HomeCommandEvent);
        }

        private void HomeCommandEvent()
        {
            ();
        }
    }

父类：

 public class BaseViewModel : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged = (sender, e) => { };

        protected virtual void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

    }

其他功能类 

 public class ApplicationPageValueConverter : BaseValueConverter<ApplicationPageValueConverter>
    {
        public override object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            switch ((ApplicationPage)value)
            {
                case :
                    return new TextBlock { Text = "404 Not Found" };
                case :
                    return new LoginView();
                case :
                    return new HomeView();
                default:
                    throw new ArgumentException("Invalid value passed to ApplicationPageViewConverter");
            }
        }

        public override object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

  public abstract class BaseValueConverter<T> : MarkupExtension, IValueConverter where T : class, new()
    {
        #region Private Members
        /// <summary>
        /// A single static instance of this value converter
        /// </summary>
        private static T mConvert = null;
        #endregion

        public override object ProvideValue(IServiceProvider serviceProvider)
        {
            return mConvert ?? (mConvert = new T());
        }

        #region Value Converter Methods
        /// <summary>
        /// The method to convert one type another
        /// </summary>
        /// <param name="value"></param>
        /// <param name="targetType"></param>
        /// <param name="parameter"></param>
        /// <param name="culture"></param>
        /// <returns></returns>
        public abstract object Convert(object value, Type targetType, object parameter, CultureInfo culture);

        /// <summary>
        /// The method to convert a value back to it's source type
        /// </summary>
        /// <param name="value"></param>
        /// <param name="targetType"></param>
        /// <param name="parameter"></param>
        /// <param name="culture"></param>
        /// <returns></returns>
        public abstract object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture);
        #endregion
    }

 public enum ApplicationPage
    {
        /// <summary>
        /// 空值
        /// </summary>
        Empty,
        /// <summary>
        /// 主页
        /// </summary>
        HomeView,
        /// <summary>
        /// 登录
        /// </summary>
        LoginView,

    }

  class NavigationPateService
    {
        public static NavigationPateService Instance { get; } = new NavigationPateService();

        private MainViewModel mainVM;

        public void Navigate(ApplicationPage page)
        {
            if (mainVM == null)
            {
                mainVM = (MainViewModel);
            }

            = page;
        }
    }