Question

我需要在textBlock中重复打印，如果数字小于80并且颜色为红色，并且大于或等于80，则使用绿色打印成功。

我怎样才能在XAML中做到这一点？

Answer 1

可悲的是，没有不平等触发器等，所以使用转换器应该这样做。

<TextBlock>
    <TextBlock.Foreground>
        <Binding Path="TestDouble">
            <Binding.Converter>
                <vc:ThresholdConverter BelowValue="{x:Static Brushes.Red}"
                                       AboveValue="{x:Static Brushes.Green}"
                                       Threshold="80" />
            </Binding.Converter>
        </Binding>
    </TextBlock.Foreground>
    <TextBlock.Text>
        <Binding Path="TestDouble">
            <Binding.Converter>
                <vc:ThresholdConverter BelowValue="Repeat"
                                       AboveValue="Successful"
                                       Threshold="80" />
            </Binding.Converter>
        </Binding>
    </TextBlock.Text>
</TextBlock>

public class ThresholdConverter : IValueConverter
{
    public double Threshold { get; set; }

    public object AboveValue { get; set; }
    public object BelowValue { get; set; }

    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        double input;
        if (value is double)
        {
            input = (double)value;
        }
        else
        {
            var converter = new DoubleConverter();
            input = (double)converter.ConvertFrom(value);
        }
        return input < Threshold ? BelowValue : AboveValue;
    }

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

Answer 2

<local:NumberToBrushConverter x:Key="numberToBrushConverter" />
<local:NumberToTextConverter x:Key="numberToTextConverter" />

<TextBlock Background="{Binding Number, Converter={StaticResource numberToBrushConverter}}"                    
Text="{Binding Number, Converter={StaticResource numberToTextConverter}"/>

class NumberToBrushConverter: IValueConverter
{
    #region IValueConverter Members

    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        int number = (int)value;

        return number < 80 ? Brushes.Red : Brushes.Green;
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return Binding.DoNothing;
    }

    #endregion
}

另一个转换器看起来类似于画笔转换器，但返回“成功”或“重复”。

如何在XAML中使用条件打印textBlock？

2 个答案: