在文本框中插入相同的值 2 次，并检查这些值是否相同 WPF

你可以研究这个样本来帮助你。我正在使用 Caliburn.Micro 来实现 MVVM

如果您对 caliburn 不满意，我解释一下：

1. 创建一个名为 Test 的 wpf .Net 项目，禁止显示创建的文件。MainWindow

2. 创建一个名为 和 视图模型（类）的窗口（它存在于 Caliburn 中具有名称的逻辑）MainViewMainViewModel

3. 添加一个名为Bootstrapper.cs

将 App.xaml 替换为：

<Application x:Class="Test.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:Test">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary>
                    <local:Bootstrapper x:Key="Bootstrapper" />
                </ResourceDictionary>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

修改文件 Bootstrapper.cs：

using Caliburn.Micro;
using System.Windows;

namespace Test
{
    public class Bootstrapper : BootstrapperBase
    {
        public Bootstrapper()
        {
            Initialize();
        }

        protected override async void OnStartup(object sender, StartupEventArgs e)
        {
            await DisplayRootViewForAsync<MainViewModel>();
        }
    }
}

修改 MainView.xaml：

<Window x:Class="Test.MainView"
        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:cal="http://www.caliburnproject.org"
        mc:Ignorable="d" 
        Title="MainView" Height="450" Width="800">
    <Grid>
        <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
            <TextBox x:Name="Login" Width="200" Height="60" Margin="10,10,30,10" Background="AliceBlue" Focusable="True"
                     cal:Message.Attach="[Event LostFocus] = [Action Login_LostFocus($source, $eventargs)];
                                         [Event GotFocus] = [Action Login_GotFocus($source, $eventargs)]"
                     FontSize="12" VerticalContentAlignment="Center" FontWeight="Medium"/>
            <Label Name="Validation" Height="60" Width="400" VerticalContentAlignment="Center"/>
            <Button x:Name="Quit" Content="Quit" Height="60" Width="70" Focusable="True"/>
        </StackPanel>

    </Grid>
</Window>

修改 MainViewModel：

using Caliburn.Micro;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

namespace Test
{
    public class MainViewModel : Screen
    {
        public string FirstLogin { get; set; }
        private string login;
        public string Login
        {
            get { return login; }
            set
            {
                if (login != value)
                {
                    login = value;
                    NotifyOfPropertyChange(() => Login);
                }
            }
        }

        private string message;
        public string Message
        {
            get { return message; }
            set
            {
                if (message != value)
                {
                    message = value;
                    NotifyOfPropertyChange(() => Message); 
                }
            }
        }

        private string validation;
        public string Validation
        {
            get { return validation; }
            set
            {
                if (validation != value)
                {
                    validation = value;
                    NotifyOfPropertyChange(() => Validation);
                }
            }
        }

        public async void Login_LostFocus(TextBox sender, RoutedEventArgs e)
        {
            if (string.IsNullOrEmpty(FirstLogin))
            {
                FirstLogin = Login;
                Login = "";
                //needed before to set focus on TextBox again
                await Task.Delay(100);
                sender.Focus();
            }
            else
            {
                if (FirstLogin.Equals(Login))
                    Validation = "Its Ok!!";
                else
                    Validation = "Its not Ok!!";
            }
        }
        public void Login_GotFocus(TextBox sender, RoutedEventArgs e)
        {
            if (!string.IsNullOrEmpty(FirstLogin) && !string.IsNullOrEmpty(Login))
            {
                FirstLogin = "";
                Login = "";
            }
            if (string.IsNullOrEmpty(FirstLogin))
                Validation = "First Try";
            else
                Validation = "Second Try";
        }

        public MainViewModel()
        {
            FirstLogin = "";
            Login = "";
            Validation = "";
        }
    }
}

我没有设置按钮退出的操作，它的存在只是为了在TextBox上按Tab键时获得焦点

仅供参考，Caliburn 使用视图文件中的 Control 名称来链接 viewModel 中具有相同名称的属性。