布尔值到可见性转换器-反转？ [英] Boolean to Visibility Converter - inverted?

问题描述

我该怎么做

<BooleanToVisibilityConverter x:Key="BoolToVis"/>

<WrapPanel>
     <TextBlock Text="{Binding ElementName=ConnectionInformation_ServerName,Path=Text}"/>
     <Image Source="Images/Icons/Select.ico" Margin="2" Height="15" Visibility="{Binding SQLConnected,Converter={StaticResource BoolToVis},ConverterParameter=true}"/>
     <Image Source="Images/Icons/alarm private.ico" Margin="2" Height="15" Visibility="{Binding SQLConnected,Converter={StaticResource BoolToVis},ConverterParameter=false}"/>
</WrapPanel>

是否可以使用布尔值到vis转换器，但无需在C中编写整个方法就可以反转会吗
还是我应该让这些图像重叠并在需要时隐藏它们？

is there a way to use the Boolean to vis converter but inverted without writing a whole method in C to do it? or should i just have these images overlap and hide one when i need to ?

推荐答案

据我所知，您必须为此编写自己的实现。这是我使用的东西：

As far as I know, you have to write your own implementation for this. Here's what I use:

public class BooleanToVisibilityConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        bool boolValue = (bool)value;
        boolValue = (parameter != null) ? !boolValue : boolValue;
        return boolValue ? Visibility.Visible : Visibility.Collapsed;
    }

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

我通常设置 ConverterParameter ='negate'，因此在代码中很清楚参数在做什么。不指定ConverterParameter会使转换器的行为类似于内置的BooleanToVisibilityConverter。如果您希望您的用法能正常工作，则可以使用 bool.TryParse（）解析ConverterParameter并对其做出反应。

And I generally set ConverterParameter='negate' so it's clear in code what the parameter is doing. Not specifying a ConverterParameter makes the converter behave like the built-in BooleanToVisibilityConverter. If you want your usage to work, you can, of course, parse the ConverterParameter using bool.TryParse() and react to it.

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