如何在 WPF 中绑定反向布尔属性? [英] How to bind inverse boolean properties in WPF?

问题描述

我拥有的是一个具有 IsReadOnly 属性的对象.如果此属性为 true，我想将按钮上的 IsEnabled 属性(例如)设置为 false.

What I have is an object that has an IsReadOnly property. If this property is true, I would like to set the IsEnabled property on a Button, ( for example ), to false.

我想相信我可以像 IsEnabled="{Binding Path=!IsReadOnly}" 一样轻松地做到这一点，但这在 WPF 中并不适用.

I would like to believe that I can do it as easily as IsEnabled="{Binding Path=!IsReadOnly}" but that doesn't fly with WPF.

我是否必须完成所有样式设置?对于将一个布尔值设置为另一个布尔值的倒数这样简单的事情来说，这似乎太冗长了.

Am I relegated to having to go through all of the style settings? Just seems too wordy for something as simple as setting one bool to the inverse of another bool.

<Button.Style>
    <Style TargetType="{x:Type Button}">
        <Style.Triggers>
            <DataTrigger Binding="{Binding Path=IsReadOnly}" Value="True">
                <Setter Property="IsEnabled" Value="False" />
            </DataTrigger>
            <DataTrigger Binding="{Binding Path=IsReadOnly}" Value="False">
                <Setter Property="IsEnabled" Value="True" />
            </DataTrigger>
        </Style.Triggers>
    </Style>
</Button.Style>

推荐答案

您可以使用 ValueConverter 为您反转 bool 属性.

You can use a ValueConverter that inverts a bool property for you.

XAML:

IsEnabled="{Binding Path=IsReadOnly, Converter={StaticResource InverseBooleanConverter}}"

转换器:

[ValueConversion(typeof(bool), typeof(bool))]
    public class InverseBooleanConverter: IValueConverter
    {
        #region IValueConverter Members

        public object Convert(object value, Type targetType, object parameter,
            System.Globalization.CultureInfo culture)
        {
            if (targetType != typeof(bool))
                throw new InvalidOperationException("The target must be a boolean");

            return !(bool)value;
        }

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

        #endregion
    }

这篇关于如何在 WPF 中绑定反向布尔属性?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！