在我的窗口。xaml我有以下代码:
xmlns:converters="clr-namespace:HMIPlc.Helpers"
<Window.Resources>
<ResourceDictionary>
<converters:ColorConverter x:Key="ColorOnChange"/>
</ResourceDictionary>
</Window.Resources>
<Rectangle Fill="{Binding Path=varUnit.InSimulation, Converter={StaticResource ColorOnChange}}"/>
我还想给函数一个字符串“黄色”或“橙色”中的值,这样我就可以对不同颜色的不同矩形使用相同的函数。
我的ColorConverter.cs帮助器目录中的类:
public class ColorConverter : IValueConverter
{
public ColorConverter()
{
}
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
bool tempBool = (bool)value;
if(tempBool == true)
{
return new SolidColorBrush(Colors.Orange);
} else
{
return new SolidColorBrush(Colors.White);
}
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
这样我就可以在xaml中确定颜色是橙色还是黄色。有什么好方法可以做到这一点吗?
如果要向转换器提供附加值,可以:
a)在转换器上添加其他属性,然后可以在XAML中分配这些属性:
public class ColorConverter : IValueConverter
{
public Color BackupColor { get; set; }
public ColorConverter()
{
}
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
bool tempBool = (bool)value;
if(tempBool == true)
{
return new SolidColorBrush(Colors.Orange);
} else
{
return new SolidColorBrush(Colors.White);
}
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}```
```xaml
...
<converters:ColorConverter x:Key="ColorOnChange" BackupColor="Yellow"/>
...
b) 利用CommandParameter,它通常是字符串文字:
<Rectangle Fill="{Binding Path=varUnit.InSimulation, Converter={StaticResource ColorOnChange}, CommandParameter='Yellow'}"/>
如果要绑定多个值,请使用多值转换器
。
public class ColorConverter : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
if (values.Length != 3 ||
!(values[0] is bool value) ||
!(values[1] is Brush brushTrue) ||
!(values[2] is Brush brushFalse))
return Binding.DoNothing;
return value ? brushTrue : brushFalse;
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
然后使用多重绑定
并指定要绑定的属性以及笔刷。
<Rectangle>
<Rectangle.Fill>
<MultiBinding Converter="{StaticResource ColorOnChange}">
<Binding Path="varUnit.InSimulation"/>
<Binding Source="{x:Static Brushes.Orange}"/>
<Binding Source="{x:Static Brushes.White}"/>
</MultiBinding>
</Rectangle.Fill>
</Rectangle>
您可以将CommandParameter
属性设置为Brush
或Color
并在转换器中强制转换“parameter”参数:
public class ColorConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
Color color = (Color)parameter;
bool tempBool = (bool)value;
if (tempBool == true)
{
return new SolidColorBrush(color);
}
else
{
return new SolidColorBrush(color);
}
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
XAML:
<Rectangle Fill="{Binding Path=varUnit.InSimulation, Converter={StaticResource ColorOnChange},
ConverterParameter={x:Static Colors.Orange}}"/>