SilverLight中的Resources

在同一个XAML中如何让多个对象使用同一个Resource，同样，不在同一个XAML中的对象也可以使用同一个Resource。Resources可以写在Grid下，也可以写在StackPanel中，还可以写在UserControl中，下面就来一一介绍。

 

一.在Grid中

<UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="EightBall.MainPage" Width="400" Height="300"> <Grid x:Name="grid1"> <Grid.Resources> <LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a> x:Key="ButtonFace"> <GradientStop Offset="0.00" Color="Yellow" /> <GradientStop Offset="0.50" Color="White" /> <GradientStop Offset="1.00" Color="Purple" /> </LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a>> </Grid.Resources> <Button Content="Click Me Frist" Width="200" Height="50" Background="{StaticResource ButtonFace}"></Button> </Grid> </UserControl>

 

 

二、在UserControl中

 

<UserControl x:Class="Resources.EightBallResource" xmlns="http://schemas.microsoft.com/client/2007" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Width="400" Height="300"> <UserControl.Resources> <LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a> x:Key="BackgroundB<a href="/tag/rush/" target="_blank" class="keywords">rush</a>"> <LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a>.GradientStops> <GradientStop Offset="0.00" Color="Yellow" /> <GradientStop Offset="0.50" Color="White" /> <GradientStop Offset="1.00" Color="Purple" /> </LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a>.GradientStops> </LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a>> </UserControl.Resources> <Grid Name="grid1" Background="{StaticResource BackgroundB<a href="/tag/rush/" target="_blank" class="keywords">rush</a>}"> </Grid> </UserControl>

 

 

三、在StackPanel中

 

<UserControl x:Class="Resources.ResourceHierarchy" xmlns="http://schemas.microsoft.com/client/2007" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Width="400" Height="300"> <StackPanel x:Name="LayoutRoot" Background="White"> <StackPanel> <StackPanel.Resources> <LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a> x:Key="ButtonFace"> <GradientStop Offset="0.00" Color="Yellow" /> <GradientStop Offset="0.50" Color="White" /> <GradientStop Offset="1.00" Color="Purple" /> </LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a>> </StackPanel.Resources> <Button Content="Panel B<a href="/tag/rush/" target="_blank" class="keywords">rush</a>" Margin="5" Background="{StaticResource ButtonFace}"></Button> <Button Content="Panel B<a href="/tag/rush/" target="_blank" class="keywords">rush</a>" Margin="5" Background="{StaticResource ButtonFace}"></Button> </StackPanel> </StackPanel> </UserControl>

 

 

不仅仅在XAML中可以设置Resources，也可以在代码中做设置，下面我们来看一个例子，

 

<UserControl x:Class="Resources.ResourcesInCode" xmlns="http://schemas.microsoft.com/client/2007" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Width="400" Height="300"> <UserControl.Resources> <LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a> x:Key="ButtonFace"> <GradientStop Offset="0.00" Color="Purple" /> <GradientStop Offset="0.50" Color="White" /> <GradientStop Offset="1.00" Color="Yellow" /> </LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a>> </UserControl.Resources> <Grid x:Name="LayoutRoot" Background="White"> <StackPanel> <Button Content="Change the Resource" Margin="5" Click="cmdChange_Click" Background="{StaticResource ButtonFace}"></Button> <Button Content="Replace the Resource (not allowed)" Margin="5" Click="cmdReplace_Click" Background="{StaticResource ButtonFace}"></Button> </StackPanel> </Grid> </UserControl>

 

完成后的界面如下：

 

 

 

现在我们来做Change the Resource的效果，使达到这样的效果：

不难发现，我们是要使这个按钮的背景色从“红-黄”变成“黄-红”

这个用代码怎么写呢？

  Private Sub cmdChange_Click(ByVal sender As Object,ByVal e As RoutedEventArgs) Dim b<a href="/tag/rush/" target="_blank" class="keywords">rush</a> as LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a> =CType(me.Resources ("ButtonFace"),LinearGradientB<a href="/tag/rush/" target="_blank" class="keywords">rush</a>) Dim color As Color = b<a href="/tag/rush/" target="_blank" class="keywords">rush</a>.GradientStops(0).Color b<a href="/tag/rush/" target="_blank" class="keywords">rush</a>.GradientStops(0).Color = b<a href="/tag/rush/" target="_blank" class="keywords">rush</a>.GradientStops(2).Color b<a href="/tag/rush/" target="_blank" class="keywords">rush</a>.GradientStops(2).Color = color End Sub

 

先定义一个LinearGradientBrush对象获取名为“ButtonFace”的LinearGradientBrush，然后定义一个Color型的变量获得LinearGradientBrush中第一个GradientStop的颜色，然后把第一个GradientStop的颜色变为第三个GradientStop的颜色，再把第三个GradientStop的颜色设为color的颜色。

 

color作为一个中转设备，成功地将第一个GradientStop和第三个GradientStop的进行了转换。