Windows Phone 7 Brush笔刷的使用

对于采用 Brush 对象的 XAML 语法,需要指定以下项之一:

  • 一个 Color 对象,指定为一个直接以 XAML 属性 (Attribute) 形式填充 Brush 类型属性 (Property) 的字符串。该字符串暗指用于填充值的 SolidColorBrush,您指定的 Color 将变为 Color (SolidColorBrush) 属性值。

  • 作为对象元素的非抽象派生类型的 Brush,具有以属性元素形式指定的 Brush 类型属性。

Brush 使用其输出绘制一个区域。下面的列表描述了不同类型的画笔:

1、SolidColorBrush - 使用纯色绘制区域。         

SolidColorBrush 对象可能是最基本的画笔,用于将外观应用到对象。可以通过类型转换语法在 XAML 中将 SolidColorBrush 指定为属性值,该语法使用关于字符串含义的几个约定。其他画笔(如 LinearGradientBrush)需要属性元素语法。可以将 Brush 属性的属性元素语法与对象元素语法 <SolidColorBrush.../> 结合在一起使用;如果要为对象元素提供 Name 值并在今后以其属性作为目标,这可能会很有用。

可以使用 ColorAnimationColorAnimationUsingKeyFrames 对象,对 SolidColorBrush 进行动画处理。若要对 SolidColorBrush 进行动画处理,通常会使用 Fill 等属性(采用 Brush)的间接定向,而不是对 SolidColorBrush 的 Color 属性进行动画处理。

通过名称选择一个预定义的 SolidColorBrush。例如,可以将 Rectangle 对象的 Fill 值设置为 RedMediumBlue。下面的示例使用预定义 SolidColorBrush 的名称来设置 RectangleFill

<Canvas
  xmlns="http://schemas.microsoft.com/client/2007"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

  <!-- This rectangle's fill is painted with a red SolidColorBrush,
       described by using a named color. -->
  <Rectangle Width="100" Height="100" Fill="Red" />
</Canvas>

2、LinearGradientBrush - 使用线性渐变绘制区域。

     LinearGradientBrush 对象使用线性渐变绘制区域。线性渐变沿直线定义渐变。该直线的终点由线性渐变的 StartPointEndPoint 属性定义。       LinearGradientBrush 画笔沿此直线绘制其 GradientStops。

默认的线性渐变是沿对角方向进行的。默认情况下,线性渐变的 StartPoint 是被绘制区域的左上角 (0,0),其 EndPoint 是被绘制区域的右下角 (1,1)。所得渐变的颜色是沿着对角方向路径插入的。

下面的示例创建了一个具有四种颜色的线性渐变,然后使用该渐变绘制 Rectangle 对象。

<Canvas
  xmlns="http://schemas.microsoft.com/client/2007"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

  <!-- This rectangle is painted with a diagonal linear gradient. -->
  <Rectangle Width="200" Height="100">
    <Rectangle.Fill>
      <LinearGradientBrush StartPoint="0,0" EndPoint="1,1">
        <GradientStop Color="Yellow" Offset="0.0" />
        <GradientStop Color="Red" Offset="0.25" />
        <GradientStop Color="Blue" Offset="0.75" />
        <GradientStop Color="LimeGreen" Offset="1.0" />
      </LinearGradientBrush>
    </Rectangle.Fill>
  </Rectangle>
</Canvas>

3、RadialGradientBrush - 使用径向渐变绘制区域。

RadialGradientBrush 对象与 LinearGradientBrush 对象类似。但是,线性渐变有一个起点和一个终点用于定义渐变矢量,而径向渐变有一个椭圆以及一个焦点 (GradientOrigin) 用于定义渐变行为。该椭圆定义渐变的终点。换言之,1.0 处的渐变停止点定义椭圆圆周处的颜色。焦点定义渐变的中心。0 处的渐变停止点定义焦点处的颜色。

<Canvas
  xmlns="http://schemas.microsoft.com/client/2007"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

  <!-- This rectangle is painted with a radial gradient. -->
  <Rectangle Width="200" Height="100">
    <Rectangle.Fill>
      <RadialGradientBrush GradientOrigin="0.5,0.5" Center="0.5,0.5"
        RadiusX="0.5" RadiusY="0.5">
        <GradientStop Color="Yellow" Offset="0" />
        <GradientStop Color="Red" Offset="0.25" />
        <GradientStop Color="Blue" Offset="0.75" />
        <GradientStop Color="LimeGreen" Offset="1" />
      </RadialGradientBrush>
    </Rectangle.Fill>
  </Rectangle> 
  
</Canvas>

4、ImageBrush - 使用图像绘制区域。    

     可以使用 ImageBrush 对象为应用程序中的文本创建装饰性效果。例如,TextBlock 对象的 Foreground 属性可以指定 ImageBrush。 如果 ImageSource 属性设置为无效格式,或其指定了无法解析的 URI,将引发 ImageFailed 事件。

下面的 XAML 示例演示如何将 Foreground 属性设置为 ImageBrush 对象,其图像用作 TextBlock 对象呈现文本的填充。

<!-- TextBlock with an image brush applied to the text. -->
<TextBlock
  Canvas.Top="120"
  FontFamily="Verdana"
  FontSize="72"
  FontStyle="Italic"
  FontWeight="Bold">
  SHRUBBERY
  <TextBlock.Foreground>
    <ImageBrush ImageSource="forest.jpg"/>
  </TextBlock.Foreground>
</TextBlock>

5、VideoBrush - 使用正在运行的视频绘制区域。

VideoBrush 是一种类似于 LinearGradientBrushImageBrush 对象的 Brush 对象。但是,VideoBrush 是使用 MediaElement 对象提供的视频内容绘制区域,而不是使用纯色、渐变或图像绘制区域。就像其他画笔类型一样,您也可以使用 VideoBrush 来绘制 Rectangle 等形状的填充或 Path 的几何内容、Canvas 的背景或者 TextBlockRun 的前景。

若要使用 VideoBrush,可以创建一个 MediaElement,将 VideoBrush 应用于要绘制的对象,然后将 VideoBrush 对象的 SourceName 属性设置为所创建的 MediaElement 的 Name 值。

下面的示例使用 VideoBrush 对象绘制 TextBlockForeground

<Canvas
  xmlns="http://schemas.microsoft.com/client/2007"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  
    <MediaElement 
      x:Name="butterflyMediaElement" 
      Source="sampleMedia/Butterfly.wmv" IsMuted="True"
      Opacity="0.0" IsHitTestVisible="False" />
      
    <TextBlock Canvas.Left="5" Canvas.Top="30"  
      FontFamily="Verdana" FontSize="120" 
      FontWeight="Bold" TextWrapping="Wrap"
      Text="Video">
      
        <!-- Paint the text with video. -->
        <TextBlock.Foreground>
          <VideoBrush SourceName="butterflyMediaElement" Stretch="UniformToFill" />
        </TextBlock.Foreground>
    </TextBlock>
    
</Canvas>


笔刷使用的例子

MainPage.xaml

<phone:PhoneApplicationPage
x:Class="BrushDemo.MainPage"
xmlns
="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x
="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:phone
="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
xmlns:shell
="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
xmlns:d
="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc
="http://schemas.openxmlformats.org/markup-compatibility/2006"
FontFamily
="{StaticResource PhoneFontFamilyNormal}"
FontSize
="{StaticResource PhoneFontSizeNormal}"
Foreground
="{StaticResource PhoneForegroundBrush}"
SupportedOrientations
="Portrait" Orientation="Portrait"
mc:Ignorable
="d" d:DesignWidth="480" d:DesignHeight="768"
shell:SystemTray.IsVisible
="True">

<!--LayoutRoot contains the root grid where all other page content is placed-->
<Grid x:Name="LayoutRoot" Background="Transparent">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>

<!--TitlePanel contains the name of the application and page title-->
<StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="24,24,0,12">
<TextBlock x:Name="ApplicationTitle" Text="DEMO" Style="{StaticResource PhoneTextNormalStyle}"/>
<TextBlock x:Name="PageTitle" Text="brushs" Margin="-3,-8,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
</StackPanel>

<!--ContentPanel - place additional content here-->
<Grid x:Name="ContentGrid" Grid.Row="1">
<Grid.RowDefinitions>
<RowDefinition Height="270*" />
<RowDefinition Height="347*" />
</Grid.RowDefinitions>
<Ellipse Height="160" HorizontalAlignment="Left" Margin="24,18,0,0" Name="ellipse1" StrokeThickness="1" VerticalAlignment="Top" Width="166" Stroke="White"></Ellipse>
<Button Content="SoildColorBrush" Grid.Row="1" Height="78" HorizontalAlignment="Left" Margin="12,0,0,0" Name="btnSoildColor" VerticalAlignment="Top" Width="462" Click="btnSoildColor_Click" />
<Button Content="LinearGradientBrush" Height="78" HorizontalAlignment="Left" Margin="12,72,0,0" Name="btnLinearGradient" VerticalAlignment="Top" Width="462" Grid.Row="1" Click="btnLinearGradient_Click" />
<Button Content="ImageBrush" Height="78" HorizontalAlignment="Left" Margin="12,214,0,0" Name="btnImage" VerticalAlignment="Top" Width="462" Grid.Row="1" Click="btnImage_Click" />
<TextBlock Height="96" Margin="24,168,0,0" Name="textBlock1" Text="TextBlock" VerticalAlignment="Top" FontSize="80" HorizontalAlignment="Left" Width="444" />
<Button Content="RadialGradientBrush" Height="78" HorizontalAlignment="Left" Margin="12,143,0,0" Name="btnRadialGradient" VerticalAlignment="Top" Width="462" Grid.Row="1" Click="btnRadialGradient_Click" />
</Grid>
</Grid>
</phone:PhoneApplicationPage>

MainPage.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;

namespace BrushDemo
{
public partial class MainPage : PhoneApplicationPage
{
// Constructor
public MainPage()
{
InitializeComponent();
}

private void btnSoildColor_Click(object sender, RoutedEventArgs e)
{
ellipse1.Fill
= new SolidColorBrush(Colors.Green);
textBlock1.Foreground
= new SolidColorBrush(Colors.Green);
}

private void btnLinearGradient_Click(object sender, RoutedEventArgs e)
{
LinearGradientBrush l
= new LinearGradientBrush();
l.StartPoint
= new Point(0.5, 0);
l.EndPoint
= new Point(0.5, 1);
GradientStop s1
= new GradientStop();
s1.Color
= Colors.Yellow;
s1.Offset
= 0.25;
l.GradientStops.Add(s1);
GradientStop s2
= new GradientStop();
s2.Color
= Colors.Orange;
s2.Offset
= 1.0;
l.GradientStops.Add(s2);
ellipse1.Fill
= l;
textBlock1.Foreground
= l;
}

private void btnImage_Click(object sender, RoutedEventArgs e)
{
ImageBrush i
= new ImageBrush();
i.Stretch
= Stretch.UniformToFill;
i.ImageSource
= new System.Windows.Media.Imaging.BitmapImage(
new Uri("/Images/IMAG0076.jpg", UriKind.Relative));
ellipse1.Fill
= i;
textBlock1.Foreground
= i;
}

private void btnRadialGradient_Click(object sender, RoutedEventArgs e)
{
RadialGradientBrush rb
= new RadialGradientBrush();
rb.Center
= new Point(0.5, 0.5);
GradientStop s1
= new GradientStop();
rb.RadiusX
= 0.5;
rb.RadiusY
= 0.5;
s1.Color
= Colors.Yellow;
s1.Offset
= 0.25;
rb.GradientStops.Add(s1);
GradientStop s2
= new GradientStop();
s2.Color
= Colors.Orange;
s2.Offset
= 1.0;
rb.GradientStops.Add(s2);
ellipse1.Fill
= rb;
textBlock1.Foreground
= rb;
}
}
}

BrushByXaml.xaml

<phone:PhoneApplicationPage
x:Class="BrushDemo.BrushByXaml"
xmlns
="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x
="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:phone
="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
xmlns:shell
="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
xmlns:d
="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc
="http://schemas.openxmlformats.org/markup-compatibility/2006"
FontFamily
="{StaticResource PhoneFontFamilyNormal}"
FontSize
="{StaticResource PhoneFontSizeNormal}"
Foreground
="{StaticResource PhoneForegroundBrush}"
SupportedOrientations
="Portrait" Orientation="Portrait"
mc:Ignorable
="d" d:DesignHeight="768" d:DesignWidth="480"
shell:SystemTray.IsVisible
="True">

<!--LayoutRoot is the root grid where all page content is placed-->
<Grid x:Name="LayoutRoot" Background="Transparent">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>

<!--TitlePanel contains the name of the application and page title-->
<StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
<TextBlock x:Name="ApplicationTitle" Text="MY APPLICATION" Style="{StaticResource PhoneTextNormalStyle}"/>
<TextBlock x:Name="PageTitle" Text="page name" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
</StackPanel>

<!--ContentPanel - place additional content here-->
<Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
<Ellipse x:Name="ellipse1" Stroke="White" StrokeThickness="2" Margin="106,28,122,350">
<Ellipse.Fill>
<RadialGradientBrush GradientOrigin="0,0.5" Center="0.5,0.5"
RadiusX
="1" RadiusY="1">
<GradientStop Color="Yellow" Offset="0" />
<GradientStop Color="Green" Offset="0.5" />
</RadialGradientBrush>
</Ellipse.Fill>
</Ellipse>
<Ellipse Margin="106,279,122,99" Name="ellipse2" Stroke="White" StrokeThickness="2">
<Ellipse.Fill>
<LinearGradientBrush StartPoint="0,0.5" EndPoint="1,0.5">
<GradientStop Color="Yellow" Offset="0.25" />
<GradientStop Color="Orange" Offset="0.75" />
</LinearGradientBrush>
</Ellipse.Fill>
</Ellipse>
</Grid>
</Grid>
</phone:PhoneApplicationPage>

BrushByXaml.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;

namespace BrushDemo
{
public partial class BrushByXaml : PhoneApplicationPage
{
public BrushByXaml()
{
InitializeComponent();
}
}
}

posted on 2011-02-11 22:56  linzheng  阅读(1601)  评论(0编辑  收藏  举报

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