Question

我正在使用BooleanToVisibilityConvertor来操纵ListBox DataTemplate中TextBlock的可见性。

这是我的XAML代码：

    <phone:PhoneApplicationPage.Resources>
    <Converters:BooleanToVisibilityConvertor x:Key="booleanToVisibilityConvertor"/>
    </phone:PhoneApplicationPage.Resources>

    <TextBlock Grid.Row="2" HorizontalAlignment="Right" Padding="0,0,7,0" Visibility="{Binding AverageConsumption, Converter={StaticResource booleanToVisibilityConvertor}}"> 
     <Run Text="{Binding AverageConsumption}"/>
     <Run Text="l./100 km."/>
    </TextBlock>

背后的代码：

public class BooleanToVisibilityConvertor : IValueConverter
{

    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        {
            if (value != null)
            {
                if (!string.IsNullOrEmpty(value.ToString()))
                {
                    return Visibility.Visible;
                }

            }
            return Visibility.Collapsed;
        }
    }

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

这是正确的，但是我需要一个（反向）转换器用于放置在同一位置的另一个TextBlock（Grid.Row =“2”HorizontalAlignment =“Right”）使用静态Text =“Partial Refueling”因此当{Binding AverageConsumption}不为null或为空时，第一个TextBlock将是可变的，第二个将被折叠，反之亦然。像这样：

    class BooleanToVisibilityConvertorReversed : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        {
            if (value != null)
            {
                if (!string.IsNullOrEmpty(value.ToString()))
                {
                    return Visibility.Collapsed;
                }
            }
            return Visibility.Visible;
        }
    }

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

我试图在XAML中声明另一个转换器：

    <phone:PhoneApplicationPage.Resources>
    <Converters:BooleanToVisibilityConvertor x:Key="booleanToVisibilityConvertor"/>
    <Converters:BooleanToVisibilityConvertorReversed x:Key="booleanToVisibilityConvertorReversed"/>
    </phone:PhoneApplicationPage.Resources>

但在InitializeComponent（）上有一个例外： '在System.Windows.ni.dll中发生'System.Windows.Markup.XamlParseException'类型的第一次机会异常' 我该如何解决这个问题？

Answer 1

好像我发现了你的问题。您的BooleanToVisibilityConvertorReversed课程不公开。公开，你的问题应该消失。

我可以声明多个转换器吗？ WP8

1 个答案: