WPF:有没有办法覆盖ControlTemplate的一部分而不重新定义整个样式？

Question

我正在尝试设置WPF xctk:ColorPicker.我想更改下拉视图和文本的背景颜色,而不重新定义整个样式.

我知道ColorPicker包含例如名为"PART_ColorPickerPalettePopup"的部件.有没有办法,我可以直接在我的风格参考本部分,比如提供一个新的背景颜色的方法只？

我想避免重新定义"PART_ColorPickerPalettePopup"的所有其他属性.

链接到我正在描述的ColorPicker

Answer 1

您可以将样式基于另一个样式并覆盖特定的setter:

<Style x:Key="myStyle" TargetType="xctk:ColorPicker" BasedOn="{StaticResource {x:Type xctk:ColorPicker}}">
    <!-- This will override the Background setter of the base style -->
    <Setter Property="Background" Value="Red" />
</Style>

但是你不能只"覆盖"ControlTemplate的一部分.不幸的是,您必须(重新)定义整个模板.

Answer 2

通过 VisualTreeHelper 从 ColorPicker 获取弹出窗口并像这样更改边框属性（弹出窗口的子项）：

   private void colorPicker_Loaded(object sender,RoutedEventArgs e)
    {
        Popup popup = FindVisualChildByName<Popup> ((sender as DependencyObject),"PART_ColorPickerPalettePopup");
        Border border = FindVisualChildByName<Border> (popup.Child,"DropDownBorder");
        border.Background = Brushes.Yellow;
    }

    private T FindVisualChildByName<T>(DependencyObject parent,string name) where T:DependencyObject
    {
        for (int i = 0;i < VisualTreeHelper.GetChildrenCount (parent);i++)
        {
            var child = VisualTreeHelper.GetChild (parent,i);
            string controlName = child.GetValue (Control.NameProperty) as string;
            if (controlName == name)
            {
                return child as T;
            }
            else
            {
                T result = FindVisualChildByName<T> (child,name);
                if (result != null)
                    return result;
            }
        }
        return null;
    }