子元素使用的自定义UserControl属性

时间:2008-12-11 04:25:45

标签: wpf xaml user-controls properties

我正在试图让一些WPF概念失效,所以我把一个简单的例子放在我想要做的事情上。我想设置一个用户控件的自定义属性,并让它由控件中的元素使用。

我一直在研究和试验,但我并没有完全理解这里的一切。任何帮助将不胜感激。

此示例的用户控件是一个简单的正方形,其中有一个圆圈:

<UserControl x:Class="CircleInSquare"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Width="100" Height="100" >
    <Grid Background="#000000">
        <Ellipse Name="Circle"
                 Margin="10"
                 Fill="?????????"
                 >
        </Ellipse>
    </Grid>
</UserControl>

它背后的VB代码:

Partial Public Class CircleInSquare

    Private _CircleColor As Color

    Public Property CircleColor() As Color
        Get
            Return _CircleColor
        End Get
        Set(ByVal value As Color)
            _CircleColor = value
        End Set
    End Property

End Class

当我使用此用户控件时,如何将CircleColor应用于控件,并将其显示为Ellipse的填充颜色?更好......我可以给它一个在VS2008 Designer中显示的默认颜色吗?

所以...如果我把这些中的一个放到我的窗口XAML中这样:

<app:CircleInSquare CircleColor="Blue" />

我希望圆圈显示为蓝色(或我为该实例选择的任何其他颜色)

4 个答案:

答案 0 :(得分:2)

很抱歉重新发布,但重新阅读后发帖,我认为你可能会更善于模板化。我在VB中附加了一些样本

Window.xaml

<Window x:Class="Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:app="clr-namespace:WpfApplicationVB1"
    Title="Window1" Height="300" Width="300">
    <Grid>
        <app:CircleInSquare Height="50" Width="50" CircleColor="Blue" SquareColor="Red"  />
    </Grid>
</Window>

CircleInSquare.xaml.vb

Partial Public Class CircleInSquare
    Public Property CircleColor() As Brush
        Get
            Return GetValue(CircleColorProperty)
        End Get

        Set(ByVal value As Brush)
            SetValue(CircleColorProperty, value)
        End Set
    End Property

    Public Shared ReadOnly CircleColorProperty As DependencyProperty = _
                           DependencyProperty.Register("CircleColor", _
                           GetType(Brush), GetType(CircleInSquare), _
                           New FrameworkPropertyMetadata(Brushes.Black))


    Public Property SquareColor() As Brush
        Get
            Return GetValue(SquareColorProperty)
        End Get

        Set(ByVal value As Brush)
            SetValue(SquareColorProperty, value)
        End Set
    End Property

    Public Shared ReadOnly SquareColorProperty As DependencyProperty = _
                           DependencyProperty.Register("SquareColor", _
                           GetType(Brush), GetType(CircleInSquare), _
                           New FrameworkPropertyMetadata(Brushes.Gray))

End Class

CircleInSquare.xaml

<UserControl x:Class="CircleInSquare"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:app="clr-namespace:WpfApplicationVB1"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <UserControl.Template>
        <ControlTemplate>
        <Border x:Name="PART_Square" Height="{TemplateBinding Height}"  Width="{TemplateBinding Width}" Background="{TemplateBinding app:CircleInSquare.SquareColor}">
        <Ellipse x:Name="PART_Ellipse" Height="{TemplateBinding Height}"
                 Width="{TemplateBinding Width}" Fill="{TemplateBinding app:CircleInSquare.CircleColor}" />
            </Border>
        </ControlTemplate>
    </UserControl.Template>
</UserControl>

答案 1 :(得分:0)

您需要在CircleInSquare类中创建DependencyProperty。做一些谷歌搜索。像下面这样使用属性的概念称为AttachedProperties,你可能需要处理CircleColorChanged事件来做你需要的事情。

<Ellipse app:CircleInSquare.CircleColor="Blue" />

答案 2 :(得分:0)

将椭圆的DataContext设置为CircleInSquare类的实例。并确保在此类上使用实现INotifyProperychanged以使其启用属性更改。如果您需要有关Propertychange

的更多信息,请查看此链接
  <Ellipse Name="Circle"
             Margin="10"
             Fill="{Binding Path= CircleColor}"
             >
    </Ellipse>

答案 3 :(得分:0)

您可以像这样设置依赖项属性:

Public Shared ReadOnly MouseOverBrushProperty As DependencyProperty = DependencyProperty.Register("MouseOverBrush", GetType(Brush), GetType(BrushableComboBox), New UIPropertyMetadata())
Public Property MouseOverBrush() As Brush
    Get
        Return CType(GetValue(MouseOverBrushProperty), Brush)
    End Get
    Set(ByVal value As Brush)
        SetValue(MouseOverBrushProperty, value)
    End Set
End Property

然后在你的xaml中你会做这样的事情

Background="{TemplateBinding MouseOverBrush}"

您可以在控件模板之外设置默认样式,如下所示:

<Style TargetType="{x:Type local:BrushableComboBox}">
    <Setter Property="MouseOverBrush" Value="Blue" />
    ...

您也可以使用普通属性来执行此操作,但依赖项属性支持绑定,这使得以后的样式更容易。

HTH

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