#WPF#的数据绑定失败，如何解决？

Question

WPF数据绑定失败：
model层的绑定的数据全部失败，ViewModel层可以绑定
先上图：

ErrorMessage是登录按钮下面空白区域要提示的内容

View层

<TextBox  Style="{DynamicResource TextUserBoxStyle}"  Text="{Binding loginModel.UserName}" FontSize="16" Width="300" Height="35"  />
                <PasswordBox  Style="{DynamicResource TextPasswordBoxStyle}"   command:PasswordHelper.Attach="True" command:PasswordHelper.Password="{Binding loginModel.Password}" FontSize="16" Grid.Row="1" Width="300" Height="35"/>
                <TextBox  Style="{DynamicResource TextVerificationBoxStyle}"  Text="{Binding loginModel.ValidationCode}" FontSize="16" Grid.Row="2" Width="300" Height="35"/>
                <TextBlock  Text="{Binding loginModel.ErrorMessage}" Foreground="Red" Grid.Row="4" TextWrapping="Wrap" HorizontalAlignment="Center" VerticalAlignment="Center"/>
                <Button Content="登   录" Command="{Binding LoginClick}" Grid.Row="3" Width="300" Height="35" Template="{StaticResource LoginButton}" Foreground="White"/>

View.cs

        public LoginView()
        {
            InitializeComponent();
            DataContext = new LoginViewModel();
        }

ViewModel层

 public partial class LoginViewModel : ObservableObject
    {
        public ICommand closeWindow { get; }
        public ICommand LoginClick { get; }
        public LoginViewModel()
        {
            closeWindow = new RelayCommand(DoClose);
            LoginClick = new RelayCommand(DoLogin);
        }
        void DoClose()
        {
            //关闭窗口（知道如何把View的窗体控件传参到此处吗？我好使用e.close()关闭它 ）
        }
        void DoLogin()
        {
            LoginModel loginModel = new LoginModel();
            if (string.IsNullOrEmpty(loginModel.UserName))
            {
                loginModel.ErrorMessage = "请输入账号！";
                return;
            }
            if (string.IsNullOrEmpty(loginModel.Password))
            {
                loginModel.ErrorMessage = "请输入密码！";
                return;
            }
            if (string.IsNullOrEmpty(loginModel.ValidationCode))
            {
                loginModel.ErrorMessage = "请输入验证码！";
                return;
            }
        }
    }

Model层

 public class LoginModel:ObservableObject
    {
        public string userName;
        public string UserName
        {
            get => userName;
            set
            {
                userName = value;
                OnPropertyChanged(nameof(UserName));
            }
        }//用户名输入框绑定源

        public string password;
        public string Password
        {
            get => password;
            set
            {
                password = value;
                OnPropertyChanged(nameof(Password));
            }
        }//密码输入框绑定源


        public string validationCode;
        public string ValidationCode
        {
            get => validationCode;
            set
            {
                validationCode = value;
                OnPropertyChanged(nameof(ValidationCode));
            }
        }//验证码输入框绑定源

        public string ErrorMessage { get; set; }
    }

知道的人请指导一下，谢谢

Answer 1

没看出来用的什么框架，说明框架可以帮助解决问题。而且你界面有个问题，绑定model没有设置mode和updatesourcetrigger属性