在前一阵子，我在网上找到了这个相册DEMO，其不仅支持图相册图片的顺(逆)序浏览，还支持简单的图
片处理（放大缩小Zoom，旋转Rotate，透明Transparency），在图片上打水印以及使用Ink在图片上涂鸭。
在线演示:
http://silverlight.services.live.com/invoke/72193/ImageSnipperV2/iframe.html
下面就是它的一些演示截图。
首先是缩放，旋转和透明处理：
然后是文字水印处理：
然后是使用Ink的涂鸭：
相信做为一个相册（图片浏览）的基本功能已经没什么问题了。
下面来看一下这个DEMO的类图，如下：
上图中的左半部用红框标识的区域是其控件设计类，因为本DEMO中所使用的控件如：按钮，滑动条，
复选框等均未使用Silverlight中所提供的控件，而是自己绘制并定义事件。因此这是我对该DEMO感兴趣的
另一个原因。而右侧则是一些工具类或图片处理类，如处理图片移动的MovableImage和TextBlock移动的
MovableTextBlock等。
下面先简要介绍一下其中的Button按钮控件的设计思路。因为其继承自ButtonBase，所以有必要先看
一下ButtonBase的代码声明，下面是xaml中的内容：
<ControlTemplate xmlns="http://schemas.microsoft.com/client/2007"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
<Grid x:Name="Part_Root" MouseEnter="btnClearMouseEnter" MouseLeave="btnClearMouseLeave"
MouseLeftButtonDown="btnClearMouseDown" MouseLeftButtonUp="btnClearMouseUp">
<Grid.Resources>
<Storyboard x:Name="Part_MouseEnter"/>
<Storyboard x:Name="Part_MouseDown"/>
<Storyboard x:Name="Part_MouseUp"/>
<Storyboard x:Name="Part_MouseLeave"/>
</Grid.Resources>
<Rectangle x:Name="Part_BackgroundRect"/>
<TextBlock x:Name="Part_Caption"/>
<Rectangle x:Name="Part_ForegroundRect"/>
<Rectangle x:Name="Part_HighlightRect"/>
</Grid>
</ControlTemplate>
从上面代码可以看出其采用控件模版的方式进行定义。但其鼠标在按钮上移入移出等状态的Storyboard
（故事板）并未进行定义。而肯体的实现被放在了相应的子类(Button.xaml和RepeatButton.xaml)进行实现。
下面就是其中的Button.xaml内容：
<ControlTemplate xmlns="http://schemas.microsoft.com/client/2007"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
<Grid x:Name="Part_Root" MouseEnter="btnClearMouseEnter" MouseLeave="btnClearMouseLeave"
MouseLeftButtonDown="btnClearMouseDown" MouseLeftButtonUp="btnClearMouseUp">
<Grid.Resources>
<Storyboard x:Name="Part_MouseEnter">
<ColorAnimation Duration="00:00:00.25" To="#3DFFFFFF" Storyboard.TargetName="Part_HighlightRect"
Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" />
</Storyboard>
<Storyboard x:Name="Part_MouseDown">
<ColorAnimation Duration="00:00:00.2" To="#22000000" Storyboard.TargetName="Part_HighlightRect"
Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" />
</Storyboard>
<Storyboard x:Name="Part_MouseUp">
<ColorAnimation Duration="00:00:00.2" To="#3DFFFFFF" Storyboard.TargetName="Part_HighlightRect"
Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" />
</Storyboard>
<Storyboard x:Name="Part_MouseLeave">
<ColorAnimation Duration="00:00:00.25" To="#00FFFFFF" Storyboard.TargetName="Part_HighlightRect"
Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)" />
</Storyboard>
</Grid.Resources>
<Rectangle x:Name="Part_BackgroundRect" StrokeThickness="4" RadiusX="16" RadiusY="36" Stroke="#46000000">
<Rectangle.Fill>
<LinearGradientBrush EndPoint="0.5,-0.4" StartPoint="0.5,1.4">
<GradientStop Color="Gray" Offset="0.242"/>
<GradientStop Color="DarkBlue" Offset="0.333"/>
</LinearGradientBrush>
</Rectangle.Fill>
</Rectangle>
<TextBlock x:Name="Part_Caption" VerticalAlignment="Center" HorizontalAlignment="Center"
Foreground="Gold" Text="Button">
<TextBlock.RenderTransform>
<TranslateTransform X="0" Y="-2"/>
</TextBlock.RenderTransform>
</TextBlock>
<Rectangle x:Name="Part_ForegroundRect" VerticalAlignment="Top" StrokeThickness="4" RadiusX="16"
RadiusY="36" Width="124" Height="32">
<Rectangle.Fill>
<LinearGradientBrush EndPoint="0.5,-0.409" StartPoint="0.5,1.409">
<GradientStop Color="#00FFFFFF" Offset="0.13"/>
<GradientStop Color="#FFFFFFFF" Offset="1"/>
</LinearGradientBrush>
</Rectangle.Fill>
</Rectangle>
<Rectangle VerticalAlignment="Top" RadiusX="16" RadiusY="36" Fill="#00FFFFFF" x:Name="Part_HighlightRect"/>
</Grid>
</ControlTemplate>
注：这样设计方式本人感觉很有意思，很有“面向对象”的味道，呵呵。
下面简要浏览一下ButtonBase.xaml.cs的代码：
[TemplatePart(Name = "Part_Root", Type = typeof(Panel))]
[TemplatePart(Name = "Part_Caption", Type = typeof(TextBlock))]
[TemplatePart(Name = "Part_ForegroundRect", Type = typeof(Rectangle))]
[TemplatePart(Name = "Part_BackgroundRect", Type = typeof(Rectangle))]
[TemplatePart(Name = "Part_HighlightRect", Type = typeof(Rectangle))]
[TemplatePart(Name = "Part_MouseEnter", Type = typeof(Storyboard))]
[TemplatePart(Name = "Part_MouseLeave", Type = typeof(Storyboard))]
[TemplatePart(Name = "Part_MouseDown", Type = typeof(Storyboard))]
[TemplatePart(Name = "Part_MouseUp", Type = typeof(Storyboard))]
public abstract partial class ButtonBase : Control
{
/// <summary>
/// 定义单击事件
/// </summary>
public event EventHandler Click;
/// <summary>
/// 执行单击事件的绑定方法
/// </summary>
protected void OnClick()
{
if (Click != null)
{
Click(this, new EventArgs());
}
}
/// <summary>
/// 标题属性
/// </summary>
public string Caption
{
get { return this.Part_Caption.Text; }
set { this.Part_Caption.Text = value; }
}
/// <summary>
/// 鼠标移入控件区域时启动Part_MouseEnter故事板，下面类似
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected virtual void Part_Root_MouseEnter(object sender, MouseEventArgs e)
{
Part_MouseEnter.Begin();
}
protected virtual void Part_Root_MouseLeave(object sender, MouseEventArgs e)
{
Part_MouseLeave.Begin();
}
protected virtual void Part_Root_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
Part_MouseDown.Begin();
}
protected virtual void Part_Root_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
Part_MouseUp.Begin();
//执行单击事件的绑定方法
OnClick();
}
protected Storyboard Part_MouseEnter, Part_MouseDown, Part_MouseLeave, Part_MouseUp;
protected Rectangle Part_ForegroundRect, Part_BackgroundRect, Part_HighlightRect;
protected Panel Part_Root;
protected TextBlock Part_Caption;
}
其实上面的代码与我们平时写.net控件类似，也是属性事件的定义。当然不同的地方就是对故事板的使用，
而故事板会让我们的按钮在鼠标触发事件时在UI上看起来更酷。当然下面还要看一下相应的Button中的内容，因
为这才是实际运行时使用的控件，其代码如下：
public partial class Button : ButtonBase
{
public Button()
{
//加载Button.xaml中的内容，为下面获取元素进行相应操作
string xaml = ResourceHelper.GetTemplate(this.GetType());
ControlTemplate template = (ControlTemplate)XamlReader.Load(xaml);
this.Template = template;
this.ApplyTemplate();
}
/// <summary>
/// 对当前模板(xaml)中的元素进行（主要是鼠标）事件绑定
/// </summary>
public override void OnApplyTemplate()
{
Part_Root = (Panel)GetTemplateChild("Part_Root");
Part_Caption = (TextBlock)GetTemplateChild("Part_Caption");
Part_ForegroundRect = (Rectangle)GetTemplateChild("Part_ForegroundRect");
Part_BackgroundRect = (Rectangle)GetTemplateChild("Part_BackgroundRect");
Part_HighlightRect = (Rectangle)GetTemplateChild("Part_HighlightRect");
Part_MouseEnter = (Storyboard)GetTemplateChild("Part_MouseEnter");
Part_MouseLeave = (Storyboard)GetTemplateChild("Part_MouseLeave");
Part_MouseDown = (Storyboard)GetTemplateChild("Part_MouseDown");
Part_MouseUp = (Storyboard)GetTemplateChild("Part_MouseUp");
Part_Root.SizeChanged += new SizeChangedEventHandler(Part_Root_SizeChanged);
Part_Root.MouseEnter += new MouseEventHandler(Part_Root_MouseEnter);
Part_Root.MouseLeave += new MouseEventHandler(Part_Root_MouseLeave);
Part_Root.MouseLeftButtonDown += new MouseButtonEventHandler(Part_Root_MouseLeftButtonDown);
Part_Root.MouseLeftButtonUp += new MouseButtonEventHandler(Part_Root_MouseLeftButtonUp);
}
/// <summary>
/// 按钮的实际高度或宽度发生变化时的处理事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void Part_Root_SizeChanged(object sender, SizeChangedEventArgs e)
{
Part_ForegroundRect.Width = Part_Root.ActualWidth - 16d;
Part_ForegroundRect.Height = Part_Root.ActualHeight - 12d;
Part_HighlightRect.Width = Part_Root.ActualWidth - 10d;
Part_HighlightRect.Height = Part_Root.ActualHeight - 8d;
if (Part_Root.ActualWidth > Part_Root.ActualHeight)
{
Part_BackgroundRect.RadiusX = Part_ForegroundRect.RadiusX = Part_HighlightRect.RadiusX =
Part_Root.ActualHeight / 2d;
Part_BackgroundRect.RadiusY = Part_ForegroundRect.RadiusY = Part_HighlightRect.RadiusY =
Part_Root.ActualWidth / 4d;
}
else
{
Part_BackgroundRect.RadiusX = Part_ForegroundRect.RadiusX = Part_HighlightRect.RadiusX =
Part_Root.ActualHeight / 4d;
Part_BackgroundRect.RadiusY = Part_ForegroundRect.RadiusY = Part_HighlightRect.RadiusY =
Part_Root.ActualWidth / 2d;
}
}
}
到这里还有另一个按钮控件RepeatButton没有介绍，其实它的内容也上面的Button代码相似，所以就不多介绍了。
当然RepeatButton最终的用处是被放在了ImageSelector控件中做为子控制被加载，这其中与我们开发“复合型”控件
相似。
下面就是Button控制的运行效果，如下所示：
当然这个DEMO在控件开发上还有一些有特色的地方，比如CheckBox控件等，我会在接下来的文章中加以说明，
呵呵。
好了，今天的内容就先到这里了。
tag:silverlight,button,imagesnipper
作者:代震军,daizhj
原文链接:http://www.cnblogs.com/daizhj/archive/2008/09/01/1281204.html
源码下载，请点击这里:)
2010年4月整理的最新相册（vs2008）：/Files/daizhj/ImageSnipper_new.rar
posted on 2008-09-05 09:49
代震军 阅读(4310)
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