• WPF使用并发词典ConcurrentDictionary实现MVVM(一) 绑定成员


        public static class Singleton<T>
            where T : new()
        {
            // Use ConcurrentDictionary for thread safety.
            private static ConcurrentDictionary<Type, T> _instances = new ConcurrentDictionary<Type, T>();
            /// <summary>
            /// Gets the instance of the Singleton class.
            /// </summary>
            public static T Instance
            {
                get
                {
                    // Safely creates the first instance or retrieves the existing instance across threads.
                    return _instances.GetOrAdd(typeof(T), (t) => new T());
                }
            }
        }

    改框架的界面绑定静态并发词典,不同页面之间可以通过该静态词典互相访问成员以及方法。该框架页面只绑定了成员属性到ViewModels,事件处理放在了后台文件,也可以增加RelayCommand到ViewModels中去,感兴趣的朋友可以自己尝试一下。

    程序框架整体如下

    using System;
    using System.Collections.Concurrent;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace WpfApp1.Utilities
    {
        public static class Singleton<T>
            where T : new()
        {
            // Use ConcurrentDictionary for thread safety.
            private static ConcurrentDictionary<Type, T> _instances = new ConcurrentDictionary<Type, T>();
            /// <summary>
            /// Gets the instance of the Singleton class.
            /// </summary>
            public static T Instance
            {
                get
                {
                    // Safely creates the first instance or retrieves the existing instance across threads.
                    return _instances.GetOrAdd(typeof(T), (t) => new T());
                }
            }
        }
    }
    Singleton.cs
    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace WpfApp1.ViewModels
    {
        public class BaseViewModel : INotifyPropertyChanged
        {
            public event PropertyChangedEventHandler PropertyChanged;
            protected void OnPropertyChanged(string info)
            {
                var handler = PropertyChanged;
                handler?.Invoke(this, new PropertyChangedEventArgs(info));
            }
        }
    }
    BaseViewModel.cs
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Windows.Controls;
    
    namespace WpfApp1.ViewModels
    {
        public class MainViewModel : ViewModels.BaseViewModel
        {
            private string _text = "我是主页面";
            public string Text
            {
                get { return _text; }
                set
                {
                    _text = value;
                    OnPropertyChanged("Text");
                }
            }
    
            //主页面的内容呈现器
            private UserControl _content = new UserControl();
            public UserControl Content
            {
                get { return _content; }
                set { _content = value; OnPropertyChanged("Content"); }
            }
        }
    }
    MainViewModel.cs
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace WpfApp1.ViewModels
    {
        public class User1ViewModel : ViewModels.BaseViewModel
        {
            private string _text = "我是User1页面";
            public string Text
            {
                get { return _text; }
                set
                {
                    _text = value;
                    OnPropertyChanged("Text");
                }
            }
        }
    }
    User1ViewModel.cs
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace WpfApp1.ViewModels
    {
        public class User2ViewModel : ViewModels.BaseViewModel
        {
            private string _text = "我是User2页面";
            public string Text
            {
                get { return _text; }
                set
                {
                    _text = value;
                    OnPropertyChanged("Text");
                }
            }
        }
    }
    User2ViewModel.cs
    <Window x:Class="WpfApp1.Views.Main"
            xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
            xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
            xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
            xmlns:local="clr-namespace:WpfApp1.Views"
            mc:Ignorable="d"
            Title="Main" Height="450" Width="800">
        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="100"/>
                <ColumnDefinition Width="*"/>
            </Grid.ColumnDefinitions>
            <Button Content="User1" Margin="0,0,0,383" Click="Button_Click_User1" />
            <Button Content="User2" Margin="0,57,0,326" Click="Button_Click_User2" />
            <!--使用内容呈现器实现页面切换-->
            <ContentPresenter  Content="{Binding Content}" Grid.Column="1"/>
            <TextBlock HorizontalAlignment="Center" Margin="0,140,0,0" TextWrapping="Wrap" Text="{Binding Text}" VerticalAlignment="Top" Height="100" Width="100" RenderTransformOrigin="0.436,0.131"/>
        </Grid>
    </Window>
    Main.xaml
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Data;
    using System.Windows.Documents;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Imaging;
    using System.Windows.Shapes;
    using WpfApp1.Utilities;
    using WpfApp1.ViewModels;
    
    namespace WpfApp1.Views
    {
        /// <summary>
        /// Main.xaml 的交互逻辑
        /// </summary>
        public partial class Main : Window
        {
            User1 User1 = new User1();
            User2 User2 = new User2();
            public Main()
            {
                InitializeComponent();
                this.DataContext = Singleton<MainViewModel>.Instance;
            }
            private void Button_Click_User1(object sender, RoutedEventArgs e)
            {
                Singleton<MainViewModel>.Instance.Content = User1;
            }
            private void Button_Click_User2(object sender, RoutedEventArgs e)
            {
                Singleton<MainViewModel>.Instance.Content = User2;
            }
        }
    }
    Main.xaml.cs
    <UserControl x:Class="WpfApp1.Views.User1"
                 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                 xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                 xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
                 xmlns:local="clr-namespace:WpfApp1.Views"
                 mc:Ignorable="d" 
                 d:DesignHeight="450" d:DesignWidth="800" Background="AliceBlue">
        <StackPanel VerticalAlignment="Center">
            <TextBlock HorizontalAlignment="Center"  TextWrapping="Wrap" Text="{Binding Text}" VerticalAlignment="Center"/>
            <Button Content="用户1界面访问主页面"  Click="Button_Click_User1" HorizontalAlignment="Center"  VerticalAlignment="Center"/>
        </StackPanel>
    </UserControl>
    User1.xaml
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Data;
    using System.Windows.Documents;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Imaging;
    using System.Windows.Navigation;
    using System.Windows.Shapes;
    using WpfApp1.Utilities;
    using WpfApp1.ViewModels;
    
    namespace WpfApp1.Views
    {
        /// <summary>
        /// User1.xaml 的交互逻辑
        /// </summary>
        public partial class User1 : UserControl
        {
            public User1()
            {
                InitializeComponent();
                this.DataContext = Singleton<User1ViewModel>.Instance;
            }
            private void Button_Click_User1(object sender, RoutedEventArgs e)
            {
                Singleton<MainViewModel>.Instance.Text = "用户1界面访问主页面";
            }
        }
    }
    User.xaml.cs
    <UserControl x:Class="WpfApp1.Views.User2"
                 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                 xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                 xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
                 xmlns:local="clr-namespace:WpfApp1.Views"
                 mc:Ignorable="d" 
                 d:DesignHeight="450" d:DesignWidth="800" Background="Coral">
        <StackPanel>
            <TextBlock HorizontalAlignment="Center"  TextWrapping="Wrap" Text="{Binding Text}" VerticalAlignment="Top"/>
            <Button Content="用户2界面访问用户1界面"  Click="Button_Click_User2" HorizontalAlignment="Center"  VerticalAlignment="Top"/>
        </StackPanel>
    </UserControl>
    User2.xaml
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Windows;
    using System.Windows.Controls;
    using System.Windows.Data;
    using System.Windows.Documents;
    using System.Windows.Input;
    using System.Windows.Media;
    using System.Windows.Media.Imaging;
    using System.Windows.Navigation;
    using System.Windows.Shapes;
    using WpfApp1.Utilities;
    using WpfApp1.ViewModels;
    
    namespace WpfApp1.Views
    {
        /// <summary>
        /// User2.xaml 的交互逻辑
        /// </summary>
        public partial class User2 : UserControl
        {
            public User2()
            {
                InitializeComponent();
                this.DataContext = Singleton<User2ViewModel>.Instance;
            }
    
            private void Button_Click_User2(object sender, RoutedEventArgs e)
            {
                Singleton<User1ViewModel>.Instance.Text = "用户2界面访问用户1界面";
            }
        }
    }
    User2.xaml.cs
    <Application x:Class="WpfApp1.App"
                 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                 xmlns:local="clr-namespace:WpfApp1"
                 StartupUri="/Views/Main.xaml">
        <Application.Resources>
             
        </Application.Resources>
    </Application>
    App.xaml
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  • 原文地址:https://www.cnblogs.com/lizhiqiang0204/p/16566755.html
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