我知道多个继承已经出来了,但有没有办法为System.
Windows.Point创建一个包装器,它可以继承它但仍然实现可绑定的依赖属性？
我正在尝试编码,以便对于我的XAML,我可以创建如下的staments而不会出现问题：
< custom：Point X =“{Binding Width,ElementName = ParentControlName}”Y =“{Binding Height,ElementName = ParentControlName}”/>
它可以使像Polygons,Paths,LineSegments和其他控件这样的编码变得更加容易.
以下代码是作为一厢情愿的想法提供的,我理解它不会起作用,但这是我希望能够做到的事情：
public class BindablePoint: DependencyObject,Point
{
public static readonly DependencyProperty XProperty =
DependencyProperty.Register("X",typeof(double),typeof(BindablePoint),new FrameworkPropertyMetadata(default(double),(sender,e) =>
{
BindablePoint point = sender as BindablePoint;
point.X = (double) e.NewValue;
}));
public static readonly DependencyProperty YProperty =
DependencyProperty.Register("Y",e) =>
{
BindablePoint point = sender as BindablePoint;
point.Y = (double)e.NewValue;
}));
public new double X
{
get { return (double)GetValue(XProperty); }
set
{
SetValue(XProperty,value);
base.X = value;
}
}
public new double Y
{
get { return (double)GetValue(YProperty); }
set
{
SetValue(YProperty,value);
base.Y = value;
}
}
}
解决方法
不幸的是,Point是一个结构体,结构体不支持继承.从
MSDN起
Note Structs do not support
inheritance,but they can implement
interfaces. For more information,see
07001.
也许这不会直接回答你的问题,但你可以在转换器的帮助下轻松绑定一个Point.在你的情况下,它会是这样的
<SomeControl.SomePointProperty>
<MultiBinding Converter="{StaticResource PointConverter}">
<Binding ElementName="ParentControlName"
Path="Width"/>
<Binding ElementName="ParentControlName"
Path="Height"/>
</MultiBinding>
</SomeControl.SomePointProperty>
PointConverter
public class PointConverter : IMultiValueConverter
{
public object Convert(object[] values,Type targetType,object parameter,System.Globalization.CultureInfo culture)
{
double xValue = (double)values[0];
double yValue = (double)values[1];
return new Point(xValue,yValue);
}
public object[] ConvertBack(object value,Type[] targetTypes,System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}
如果你只想绑定X值并具有静态Y值,你可以这样做
<SomeControl SomePointProperty="{Binding Path=Width,ElementName=ParentControlName,Converter={StaticResource PointXConverter},ConverterParameter=20}"/>
PointXConverter
public class PointXConverter : IValueConverter
{
public object Convert(object value,System.Globalization.CultureInfo culture)
{
double progressBarValue = (double)value;
double yValue = System.Convert.ToDouble(parameter);
return new Point(progressBarValue,yValue);
}
public object ConvertBack(object value,System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}
