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C＃WPF IsEnabled使用多个绑定？

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39

我有一个描述GUI部分的WPF xaml文件，我希望特定控件的启用/禁用依赖于其他两个控件 . 代码看起来像这样：

<ComboBox Name="MyComboBox"
          IsEnabled="{Binding ElementName=SomeCheckBox, Path=IsChecked}"/>

但我希望它依赖于另一个复选框，所以类似于：

<ComboBox Name="MyComboBox"
          IsEnabled="{Binding ElementName=SomeCheckBox&AnotherCheckbox, Path=IsChecked}"/>

最好的方法是什么？我情不自禁地觉得我错过了一些明显的东西或者错误的方式？

c# wpf binding combobox isenabled

4 回答

  • 12

    我相信您可能必须使用MultiBinding与MultiValueConverter . 看这里：http://www.developingfor.net/wpf/multibinding-in-wpf.html

    这是一个直接相关的例子：http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/5b9cd042-cacb-4aaa-9e17-2d615c44ee22

    回复于
  • 62

    您可以将MultiBinding与实现IMultiValueConverter的转换器一起使用 .

    只需给出答案，您就可以（几乎）复制并粘贴：

    需要的静态资源：

    <converterNamespace:BooleanAndConverter x:Key="booleanAndConverter" />

    ComboBox：

    <ComboBox Name="MyComboBox">
  <ComboBox.IsEnabled>
    <MultiBinding Converter="{StaticResource booleanAndConverter}">
      <Binding ElementName="SomeCheckBox" Path="IsChecked" />
      <Binding ElementName="AnotherCheckbox" Path="IsChecked"  />
    </MultiBinding>
  </ComboBox.IsEnabled>
</ComboBox>

    转换器的代码：

    namespace ConverterNamespace
{
    public class BooleanAndConverter : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            foreach (object value in values)
            {
                if ((value is bool) && (bool)value == false)
                {
                    return false;
                }
            }
            return true;
        }
        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotSupportedException("BooleanAndConverter is a OneWay converter.");
        }
    }
}
    回复于
  • 12

    您也可以尝试相同的较短版本：

    public class BooleanAndConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return values.OfType<IConvertible>().All(System.Convert.ToBoolean);
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotSupportedException();
    }
}

public class BooleanOrConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return values.OfType<IConvertible>().Any(System.Convert.ToBoolean);
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotSupportedException();
    }
}

    当然，您也可能需要转换器以实现可见性：

    public class BooleanOrToVisibilityConverter : IMultiValueConverter
{
    public Visibility HiddenVisibility { get; set; }

    public bool IsInverted { get; set; }

    public BooleanOrToVisibilityConverter()
    {
        HiddenVisibility = Visibility.Collapsed;
        IsInverted = false;
    }

    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        bool flag = values.OfType<IConvertible>().Any(System.Convert.ToBoolean);
        if (IsInverted) flag = !flag;
        return flag ? Visibility.Visible : HiddenVisibility;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

public class BooleanAndToVisibilityConverter : IMultiValueConverter
{
    public Visibility HiddenVisibility { get; set; }

    public bool IsInverted { get; set; }

    public BooleanAndToVisibilityConverter()
    {
        HiddenVisibility = Visibility.Collapsed;
        IsInverted = false;
    }

    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        bool flag = values.OfType<IConvertible>().All(System.Convert.ToBoolean);
        if (IsInverted) flag = !flag;
        return flag ? Visibility.Visible : HiddenVisibility;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}
    回复于
  • 0

    作为qqbenq答案的扩展：

    添加了处理Collection的 Count 的函数，例如，如果要检查是否选择了 ListView 的某个项目 .

    Converter:

    public class IsEnabledConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        foreach (var value in values)
        {
            switch (value)
            {
                case bool b when !b:
                case int i when i == 0:
                    return false;
            }
        }

        return true;
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        return null;
    }
}

    Namespace <theNamespace:IsEnabledConverter x:Key="IsEnabledConverter"/>

    Button

    <Button x:Name="MyButton">
    <Button.IsEnabled>
        <MultiBinding Converter="{StaticResource IsEnabledConverter}">
            <Binding ElementName="MyListView" Path="SelectedItems.Count"/>
            <Binding ElementName="MyCheckBox" Path="IsChecked"/>
        </MultiBinding>
    </Button.IsEnabled>
</Button>
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