WPF元素数据绑定IsEnabled（但为false） [英] WPF element databinding for IsEnabled (but for false)

问题描述

我有一个复选框

我在WPF中是一个初学者， code>，我想禁用当 RadioButton 未选择。
我当前的语法是：

 < CheckBox IsEnabled ={Binding ElementName = rbBoth，Path = IsChecked} >显示全部< / CheckBox> 
  

所以基本上，我想IsEnabled取与我目前提供的绑定表达式相反的值。

我该如何做？感谢。

解决方案

您需要使用所谓的值转换器（实现IValueConverter的类）。一个非常基本的例子一个类如下所示。 （观看剪辑...）

  public class NegateConverter：IValueConverter 
 {
 
公共对象转换（对象值，类型targetType，对象参数，CultureInfo文化）
 {
 if（value is bool）{
 return！（bool）value; 
} 
返回值; 
} 
 
 public object ConvertBack（对象值，类型targetType，对象参数，CultureInfo文化）
 {
 if（value is bool）{
 return ！（bool）value; 
} 
返回值; 
} 
 
} 
  

然后将其包含在XAML你可以这样做：

 < UserControl xmlns：local =clr-namespace：MyNamespace> 
< UserControl.Resources> 
< local：Negateconverter x：Key =negate/> 
< /UserControl.Resources> 
 
 ... 
< CheckBox IsEnabled ={Binding IsChecked，ElementName = rbBoth，Converter = {StaticResource negate}}
 Content =Show all/& 
 
< / UserControl> 
  

I'm a starter in WPF, and there's something I can't seem to figure out.

I have a CheckBox that I would like to disable when a RadioButton is not selected. My current syntax is:

<CheckBox IsEnabled="{Binding ElementName=rbBoth, Path=IsChecked}">Show all</CheckBox>

So basically, I want IsEnabled to take the opposite value than the binding expression I'm currently supplying.

How can I do this? Thanks.

解决方案

You need to use what's called a value converter (a class that implements IValueConverter.) A very basic example of such a class is shown below. (Watch for clipping...)

public class NegateConverter : IValueConverter
{

    public object Convert( object value, Type targetType, object parameter, CultureInfo culture )
    {
        if ( value is bool ) {
            return !(bool)value;
        }
        return value;
    }

    public object ConvertBack( object value, Type targetType, object parameter, CultureInfo culture )
    {
        if ( value is bool ) {
            return !(bool)value;
        }
        return value;
    }

}

Then to include it in your XAML you would do something like:

<UserControl xmlns:local="clr-namespace:MyNamespace">
    <UserControl.Resources>
        <local:NegateConverter x:Key="negate" />
    </UserControl.Resources>

    ...
    <CheckBox IsEnabled="{Binding IsChecked, ElementName=rbBoth, Converter={StaticResource negate}}"
              Content="Show all" />

</UserControl>

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