WPF 之 数据与命令绑定 （MVVM方式）

<Grid>
   <StackPanel>
       <!-- 数据绑定 -->
       <TextBox Width="300" x:Name="TextBox1" Height="30" Margin="15" Text="{Binding SearchText}"/>
       <!-- 命令绑定 -->
       <Button Content="展示" Width="50" Height="30" Margin="15" Command="{Binding SignInCommand}" />
   </StackPanel>
</Grid>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.ComponentModel;
namespace dataEventBinding.baseCommon
{
    public class NotifyPropertyChanged : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged = (sender, e) => { };
        // 通知属性更改 <param name="propertyName" />
        protected void RaisePropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
namespace dataEventBinding.baseCommon
{
    class RelayCommand : ICommand
    {
        public event EventHandler CanExecuteChanged = (sender, e) => { };
        private Action mAction;
        public RelayCommand(Action action) {
            this.mAction = action;
        }
        public bool CanExecute(object parameter)
        {
            return true;
        }
        public void Execute(object parameter)
        {
            mAction.Invoke();
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;
namespace dataEventBinding.ViewModels
{
    public class MainViewModel : baseCommon.NotifyPropertyChanged
    {
        public MainViewModel()
        {
            SignInCommand = new baseCommon.RelayCommand(() => {
                MessageBox.Show(searchText);
            });
        }
        private string searchText;
        // 发布方法 供外面使用
        public ICommand SignInCommand { get; private set; }
        public string SearchText
        {
            get { return searchText; }
            set { searchText = value; RaisePropertyChanged(nameof(searchText)); }
        }
    }
}

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;
namespace dataEventBinding.Views
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        // 创建对象并赋值给 window.DataContext
        public ViewModels.MainViewModel m = new ViewModels.MainViewModel(); 
        public MainWindow()
        {           
            InitializeComponent();
            m.SearchText = "water";
            this.DataContext = m;
        }
    }
}