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

问题描述

我有自己的用户控件，一个 LabeledTextBox，它是 Label 和一个..well，TextBox 的组合.此控件有两个属性:Caption 将绑定到 Label 的标题，以及 Value 将绑定到 TextBox 的文本.

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.

代码:

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>

用法:

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

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

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

这详细说明了 TemplateBinding 和 RelativeSource TemplatedParent 之间的区别.我已经相应地更改了我的代码，但仍然感觉我错过了一步.OneWay 绑定确实有效，我的文本框绑定到 Value 属性，但更改不会注册.

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.

如何让它工作?

推荐答案

在此处更改模式.

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

它在我的最后工作

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