如何在UserControl中使用TwoWay绑定？ [英] How to use TwoWay binding from within a UserControl?

问题描述

我有自己的UserControl，一个 LabeledTextBox ，它是一个标签和a..well的组合， TextBox 。该控件有两个属性： Caption ，它们将被绑定到标签和 c $ c c c



代码：

  public class LabeledTextBox：Control 
 {
 static LabeledTextBox（）
 {
 DefaultStyleKeyProperty.OverrideMetadata（typeof（LabeledTextBox），新的FrameworkPropertyMetadata（typeof（LabeledTextBox）））; 
} 
 
 public string Caption 
 {
 get {return（string）GetValue（CaptionProperty）; } 
 set {SetValue（CaptionProperty，value）; } 
} 
 
 //使用DependencyProperty作为Caption的后备存储。这使得动画，样式，绑定等... 
 public static readonly DependencyProperty CaptionProperty = 
 DependencyProperty.Register（Caption，typeof（string），typeof（LabeledTextBox），new UIPropertyMetadata（） ）; 
 
 
 public string Value 
 {
 get {return（string）GetValue（ValueProperty）; } 
 set {SetValue（ValueProperty，value）; } 
} 
 
 //使用DependencyProperty作为Value的后备存储。这可以使动画，样式，绑定等... 
 public static readonly DependencyProperty ValueProperty = 
 DependencyProperty.Register（Value，typeof（string），typeof（LabeledTextBox），new UIPropertyMetadata（） ）; 
 
 
} 
  

XAML：

 < Style TargetType ={x：Type local：LabeledTextBox}> 
< Setter Property =Template> 
< Setter.Value> 
< ControlTemplate TargetType ={x：Type local：LabeledTextBox}> 
< Grid> 
< Grid> 
 
< Grid.RowDefinitions> 
< RowDefinition /> 
< RowDefinition /> 
< /Grid.RowDefinitions> 
 
< Label Grid.Row =0Content ={TemplateBinding Caption}/> 
< TextBox Name =BoxMargin =3,0,3,3Grid.Row =1Text ={Binding Value，RelativeSource = {RelativeSource TemplatedParent}，Mode = TwoWay}/ > 
 
< / Grid> 
< / Grid> 
< / ControlTemplate> 
< /Setter.Value> 
< / Setter> 
< / Style> 
  

用法：

 code>< uc：LabeledTextBox Caption =Code：Value ={Binding ExpenseCode}/> 
  

最初我以为我在这里找到了我的答案： WPF TemplateBinding vs RelativeSource TemplatedParent

详细说明了 TemplateBinding 和 RelativeSource TemplatedParent 。我已经相应地改变了我的代码，但仍然觉得我失去了一个步骤。 OneWay绑定工作，我的文本框绑定到Value属性，但更改不会注册。

如何让它工作？

解决方案

在此处更改模式。

  uc：LabeledTextBox Caption =Code：Value ={Binding ExpenseCode，Mode = TwoWay}/> 
  

它在我的结束工作

I have my own UserControl, a LabeledTextBox which is the combination of a Label and a..well, TextBox. This Control has two properties: Caption which will be bound to the caption of the Label, and Value which will be bound to the Text of the TextBox.

Code:

public class LabeledTextBox : Control
{
    static LabeledTextBox()
    {
        DefaultStyleKeyProperty.OverrideMetadata(typeof(LabeledTextBox), new FrameworkPropertyMetadata(typeof(LabeledTextBox)));
    }

    public string Caption
    {
        get { return (string)GetValue(CaptionProperty); }
        set { SetValue(CaptionProperty, value); }
    }

    // Using a DependencyProperty as the backing store for Caption.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty CaptionProperty =
        DependencyProperty.Register("Caption", typeof(string), typeof(LabeledTextBox), new UIPropertyMetadata(""));


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

    // Using a DependencyProperty as the backing store for Value.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty ValueProperty =
        DependencyProperty.Register("Value", typeof(string), typeof(LabeledTextBox), new UIPropertyMetadata(""));


}

XAML:

<Style TargetType="{x:Type local:LabeledTextBox}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type local:LabeledTextBox}">
                <Grid>
                    <Grid>

                    <Grid.RowDefinitions>
                        <RowDefinition />
                        <RowDefinition />
                    </Grid.RowDefinitions>

                    <Label Grid.Row="0" Content="{TemplateBinding Caption}" />
                    <TextBox  Name="Box" Margin="3,0,3,3" Grid.Row="1" Text="{Binding Value, RelativeSource={RelativeSource TemplatedParent}, Mode=TwoWay}" />

                    </Grid>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Usage:

<uc:LabeledTextBox Caption="Code:" Value="{Binding ExpenseCode}"  />

Initially I thought I had found my answer here: WPF TemplateBinding vs RelativeSource TemplatedParent

That details the difference between TemplateBinding and RelativeSource TemplatedParent. I've changed my code accordingly, but it still feels like I'm missing a step. The OneWay binding does work, my textbox is bound to the Value property, but changes do not register.

How do I get this to work?

解决方案

Change the mode here.

<uc:LabeledTextBox Caption="Code:" Value="{Binding ExpenseCode,Mode=TwoWay}"  /> 

it worked at my end

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