Question

为什么view.aBOX仅在TextBoxA内更新MainWindow？以及如何解决这个问题？

当我将view传递给w时，它运行得非常好。甚至调试器也会使用view.aBOX中的消息更新w。但是，它永远不会从TextBoxA内更新w。

示例代码：

//MAIN
public partial class MainWindow : Window
{
    ViewModel view; //DEBUGGER SHOWS aBOX = "Worker STARTED", But no update
    Worker w; 

    public MainWindow()
    {
        this.view = new ViewModel();
        this.DataContext = this.view;

        //TEST
        this.view.aBOX = "BINDING WORKS!!"; //UPDATES FINE HERE

        this.w = new Worker(this.view); 
    }
}

//VIEW
public class ViewModel
{
    public string aBOX { get; set; }
}

//WORKER
public class Worker
{
    ViewModel view;
    public Worker(ViewModel vm)
    {
        this.view = vm; 
        this.view.aBOX = "Worker STARTED"; //NEVER SEE THIS IN TextBoxA
    }
}

//XAML/WPF
<TextBox Name="TextBoxA" Text="{Binding Path=aBOX, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" />

Answer 1

您需要实现INotifyPropertyChanged才能将更改传播到绑定引擎。

如果您能够使用基类，则可以使用：

public class Notify : INotifyPropertyChanged
{
    #region INotifyPropertyChanged Members

    public event PropertyChangedEventHandler PropertyChanged;

    protected void RaisePropertyChanged(Expression<Func<object>> exp)
    {
        string propertyName = ((exp.Body as UnaryExpression).Operand as MemberExpression).Member.Name;

        var handler = PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(propertyName));
    }

    #endregion
}

使用它：

public int Property
{
  //getter
  set
  {
    property = value;
    RaisePropertyChanged(() => Property);
  }  
}

使用此代码，您可以轻松地重构属性，而不必处理魔术字符串。此外，你得到intellisense。

WPF，为什么我的Binding仅从MainWindow更新？

1 个答案: