c# - WPF MVVM 绑定从 ViewModel 工作到 XAML，但不是相反。我究竟做错了什么？

问题描述

所以这是我的 XAML：

    <TextBox Name="FirstNameTextBox"
             Text="{Binding Mode=TwoWay, Path=FirstName}" 
             Style="{StaticResource StandardTextBoxTheme}"
             Width="180"
             HorizontalAlignment="Left"
             Margin="0 0 0 10" />
    <Button Name="CreatePersoenlicheUntersuchungButton"
            Content="Unterlagen erstellen"
            Style="{StaticResource StandardButtonTheme}"
            Command="{Binding CreateMedicalExaminationCommand}" 
            HorizontalAlignment="Left" />

这是我的 ViewModel：

public class MedicalExaminationViewModel : INotifyPropertyChanged
{
    private IGlobalConfig _globalConfig;
    private ILogger _logger;
    private IDataAccess _dataAccess;

    private string _firstName;
    public string FirstName
    {
        get { return _firstName; }
        set
        {
            _firstName = value;
            OnPropertyChanged(this, () => FirstName);
        }
    }

    private string _lastName;
    public string LastName
    {
        get { return _lastName; }
        set
        {
            _lastName = value;
            OnPropertyChanged(this, () => LastName);
        }
    }


    public event PropertyChangedEventHandler PropertyChanged;

    public ICommand CreateMedicalExaminationCommand { get; set; }

    public MedicalExaminationViewModel(ILogger logger, IDataAccess dataAccess, IGlobalConfig globalConfig)
    {
        _globalConfig = globalConfig;
        _logger = logger;
        _dataAccess = dataAccess;

        CreateMedicalExaminationCommand =
           new RelayCommand(new Action<object>(CreateMedicalExaminationAsync));
    }
    // This method gets called when pressing the Button and the Text in the Textboxes gets updated after setting the Properties here.
    public async void CreateMedicalExaminationAsync(object obj)
    {            
        FirstName = "Test_FirstName";
        LastName = "Test_LastName";

        System.Windows.Forms.MessageBox.Show(FirstName);
        System.Windows.Forms.MessageBox.Show(LastName);
    }

    public virtual void OnPropertyChanged<T>(object source, Expression<Func<T>> propertyExpression)
    {
        string propertyName = GetPropertyName(source, propertyExpression);
        if (PropertyChanged != null)
        {
            PropertyChanged(source, new PropertyChangedEventArgs(propertyName));
        }
    }
  
    public string GetPropertyName<T>(object source, Expression<Func<T>> propertyExpression)
    {
        var memberExpression = propertyExpression.Body as MemberExpression;
        var propertyName = memberExpression.Member.Name;

        return propertyName;
    }
}

当我填写 TextBox 并按下按钮时，CreateMedicalExaminationAsync() 会被调用。但是 FirstName 属性为空。当我在 ViewModel 中设置 FirstName 属性时，它会在视图中按应有的方式更新。如何将 TextBox.Text 放入 ViewModel 中的属性中？提前致谢！

编辑：删除 Yarik 提到的样式使其立即生效。非常感谢。

标签： c#wpfxamldata-bindingviewmodel

c# - WPF MVVM 绑定从 ViewModel 工作到 XAML，但不是相反。我究竟做错了什么？

问题描述

解决方案

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