直接使用键盘输入时，TextBox绑定丢失

Question

我有一个用户控件正在由另一个用户控件通过提供的ValueProperty更新（请参见下面的代码Window.XAML绑定）。当我的另一个用户控件的属性正在更新时，文本框也将通过值绑定进行更新。

但是，当我直接在用户控件文本框中键入内容时，请再次使用其他用户控件。 文本框不会再更新。 看来我的TextBox UserControl的ValueProperty已被覆盖。 我假设当我直接在TextBox中键入文本时，Text = {Binding ...}丢失并被覆盖。

//Window.XAML
<veraControls:veraCommandPanel Name="commandCTRL" Value="{Binding ElementName=MyKeyPad, Path=Value}"  HorizontalAlignment="Right" Width="360.057" Margin="0,266,-92.834,0" FontSize="42" FontFamily="lcdD" Foreground="LimeGreen" Height="54.901" VerticalAlignment="Top" />

//Here is my userControl
<UserControl x:Name="PART_command" x:Class="Vera.WPFControls.veraCommandPanel"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Height="Auto" Width="300"
xmlns:local="clr-namespace:Vera.WPFControls">
<StackPanel>
    <StackPanel.Resources>
        <Style x:Name="PART_veraCommand" TargetType="{x:Type local:veraCommandPanel}">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type local:veraCommandPanel}">
                        <Border Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}">
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </StackPanel.Resources>
    <TextBox Height="55" Name="PART_txtCommand"  Text="{Binding ElementName=PART_command, Path=Value}" VerticalAlignment="Top" />
</StackPanel>

//TextBox UserControl's Code Behind
namespace Vera.WPFControls
{
/// <summary>
/// Interaction logic for veraCommandPanel.xaml
/// </summary>
public partial class veraCommandPanel : UserControl, INotifyPropertyChanged
{

    public veraCommandPanel()
    {
       InitializeComponent();
       this.DataContext = this;
    }


    public event PropertyChangedEventHandler PropertyChanged;
    protected void NotifyPropertyChanged(String info)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
    }

    public static  DependencyProperty ValueProperty =
           DependencyProperty.Register("Value", typeof(string), typeof(veraCommandPanel));

    //, new UIPropertyMetadata(false, new PropertyChangedCallback(PropChanged)));

    public string Value
    {
        get
        {
            return (string)GetValue(ValueProperty);
        }
        set
        {
            SetValue(ValueProperty, value);

    }

}

}

Answer 1

尝试TwoWay绑定，如下所示：

Text="{Binding ElementName=PART_command, Path=Value, Mode=TwoWay}"