Visual studio 2010 在WPF设计器中拖放控件时，VS2010从何处获取默认属性值

在WPF设计器中拖放控件时，Visual Studio 2010将创建默认属性值

<UserControl x:Class="TestPanel.UserControl1"
    <Grid>
        <Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="12,12,0,0" Name="button1" VerticalAlignment="Top" Width="75" />
    </Grid>
</UserControl>

---

高度

和宽度都是

依赖属性

，当您为控件注册依赖属性时，您可以设置Visual Studio或

XAML设计器

可以使用的依赖属性的默认值

默认值在

FrameworkPropertyMatadata

类构造函数中设置，如下代码所示：

//Default value is set to Top
Control.VerticalContentAlignmentProperty = DependencyProperty.Register("VerticalContentAlignment", typeof(VerticalAlignment), typeof(Control), new FrameworkPropertyMetadata(VerticalAlignment.Top), new ValidateValueCallback(FrameworkElement.ValidateVerticalAlignmentValue));

//Default value is set to Left
Control.HorizontalContentAlignmentProperty = DependencyProperty.Register("HorizontalContentAlignment", typeof(HorizontalAlignment), typeof(Control), new FrameworkPropertyMetadata(HorizontalAlignment.Left), new ValidateValueCallback(FrameworkElement.ValidateHorizontalAlignmentValue));

---

Height

和

Width

都是

依赖属性

，当您为控件注册依赖属性时，可以设置

Visual Studio

或

XAML设计器

可以使用的依赖属性的默认值

默认值在

FrameworkPropertyMatadata

类构造函数中设置，如下代码所示：

//Default value is set to Top
Control.VerticalContentAlignmentProperty = DependencyProperty.Register("VerticalContentAlignment", typeof(VerticalAlignment), typeof(Control), new FrameworkPropertyMetadata(VerticalAlignment.Top), new ValidateValueCallback(FrameworkElement.ValidateVerticalAlignmentValue));

//Default value is set to Left
Control.HorizontalContentAlignmentProperty = DependencyProperty.Register("HorizontalContentAlignment", typeof(HorizontalAlignment), typeof(Control), new FrameworkPropertyMetadata(HorizontalAlignment.Left), new ValidateValueCallback(FrameworkElement.ValidateHorizontalAlignmentValue));