[英]WPF control derived from Label: are custom properties (with DP) not using the setter?
[英]Custom control derived from control with controls inside and properties
我以这个控件为例:
泛型
<Style TargetType="{x:Type local:EditLabel}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:EditLabel}" >
<StackPanel Name ="PART_SPPrincipal" VerticalAlignment="Center" Orientation="Horizontal" >
<TextBox Name="PART_TextBox" Width="100" HorizontalAlignment="Left" />
<Label Name="PART_Label" BorderBrush="Black" BorderThickness="1"
HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
</StackPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
EditLabel.cs
public class EditLabel : UserControl
{
static EditLabel()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(EditLabel), new FrameworkPropertyMetadata(typeof(EditLabel)));
}
private Label _label;
public static readonly DependencyProperty LabelWidthProperty = DependencyProperty.Register("LabelWidth", typeof(int), typeof(EditLabel),
new FrameworkPropertyMetadata(10, FrameworkPropertyMetadataOptions.AffectsRender));
[Description("Establece el ancho de la etiqueta de descripción"), Category("Lutx")]
public int LabelWidth
{
get
{
return (int)GetValue(LabelWidthProperty);
}
set
{
SetValue(LabelWidthProperty, value);
_label.Width = value;
}
}
public override void OnApplyTemplate()
{
//_txtBox = GetTemplateChild("PART_TextBox") as ButtonEdit;
_label = GetTemplateChild("PART_Label") as Label;
}
}
问题是当我更改LabelWidth时什么也没有发生,我尝试过以下方法:
1)在设计时,当我在行上设置断点时,更改LabelWidth不会发生任何事情:
_label.Width = value;
从不停止执行时间
2)我的事也许是我尝试通过代码来完成的,并且在标签行的<Label Name="PART_Label" Width="{Binding LabelWith}"...
尝试时: <Label Name="PART_Label" Width="{Binding LabelWith}"...
什么都没发生
3)当我将控件放在窗口中时
<local:EditLabel LabelWidth="30"/>
什么都没发生
目前我没有更多的主意,因此,非常感谢您的帮助
在LabelWidthProperty(DependencyProperty)的声明中,在PropertyMetadata中放置一个回调,并将_label.Width
设置为e.NewValue
。 那应该解决您的问题。 删除_label.Width = value;
从LabelWidth
谢谢您的TYY,我无法投票给您,因为我没有15个声誉。
是的,似乎是正确的方法,但是问题是PropertyChangedCallback必须声明为静态,而不是实例的一部分,因此更改后请参见代码。 总是异常,因为_label为null。 查看新代码(还对OnLabelChanged注释行进行了测试):
公共类EditLabel:UserControl {
static EditLabel()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(EditLabel), new FrameworkPropertyMetadata(typeof(EditLabel)));
}
private Label _label;
public Label Label
{
get { return _label; }
set { _label = value; }
}
public static readonly DependencyProperty LabelWidthProperty = DependencyProperty.Register("LabelWidth", typeof(int), typeof(EditLabel),
new PropertyMetadata(10, new PropertyChangedCallback(OnLabelChanged)));
[Description("Establece el ancho de la etiqueta de descripción"), Category("Lutx")]
public int LabelWidth
{
get
{
return (int)GetValue(LabelWidthProperty);
}
set
{
SetValue(LabelWidthProperty, value);
}
}
private static void OnLabelChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
EditLabel el = obj as EditLabel;
el.Label.Width = (int)e.NewValue;
//Label lbl = el.GetTemplateChild("PART_Label") as Label;
//lbl.Width(int)e.NewValue;
}
public override void OnApplyTemplate()
{
//_txtBox = GetTemplateChild("PART_TextBox") as ButtonEdit;
_label = GetTemplateChild("PART_Label") as Label;
SetBinding(LabelWidthProperty, new Binding
{
Source = _label,
Path = new PropertyPath("Width")
});
}
}
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