2.0交互之InkPresenter(涂鸦板)

介绍
Silverlight 2.0 人机交互：InkPresenter(涂鸦板)
    InkPresenter - 涂鸦板，也就是在面板上呈现墨迹。InkPresenter 可以包含子控件
    Cursor - 鼠标移动到 InkPresenter 上面时，鼠标指针的样式
    Background - 涂鸦板背景
    Opacity - 面板上墨迹的不透明度
    Clip - InkPresenter 的剪辑区域
    Stroke.DrawingAttributes - Stroke（笔划）的外观属性
    UIElement.CaptureMouse() - 为 UIElement 对象启用鼠标捕捉
    UIElement.CaptureMouse() - 为 UIElement 对象释放鼠标捕捉


在线DEMO
http://www.cnblogs.com/webabcd/archive/2008/10/09/1307486.html


示例
InkPresenter.xaml

<UserControl x:Class="Silverlight20.Interactive.InkPresenter"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d">
    <Canvas>

        <!--InkPresenter 的外围的带边框的背景图-->
        <Rectangle Width="420" Height="350" Stroke="Black" StrokeThickness="1">
            <Rectangle.Fill>
                <ImageBrush ImageSource="/Silverlight20;component/Images/Background.jpg" Stretch="Fill" />
            </Rectangle.Fill>
        </Rectangle>
        
        <!--用于描绘 InkPresenter 的工作区-->
        <Rectangle Canvas.Top="10" Canvas.Left="10" Width="400" Height="300" RadiusX="25" RadiusY="25" Fill="Black" Opacity="0.2" />

        <!--
        InkPresenter - 涂鸦板，也就是在面板上呈现墨迹
            Cursor - 鼠标移动到 InkPresenter 上面时，鼠标指针的样式
                Arrow - 箭头
                Hand - 手形 
                Wait - 沙漏
                IBeam - “I”字形 
                Stylus - 点
                Eraser - 橡皮
                None - 无
            Background - 涂鸦板背景。建议设置其为“Transparent”，需要的话可以使用其他控件来描绘背景
            Opacity - 面板上墨迹的不透明度
            Clip - InkPresenter 的剪辑区域。本例给 InkPresenter 做了一个圆角效果，其Clip值由 Blend 生成
        -->
        <InkPresenter x:Name="inkPresenter" Cursor="Stylus" Canvas.Top="10" Canvas.Left="10" Width="400" Height="300" Background="Transparent"
         
            MouseLeftButtonDown="inkPresenter_MouseLeftButtonDown" 
            MouseLeftButtonUp="inkPresenter_MouseLeftButtonUp" 
            MouseMove="inkPresenter_MouseMove" 
            Clip="M0.5,25.5 C0.5,11.692882 11.692882,0.5 25.5,0.5 L374.5,0.5 C388.30713,0.5 399.5,11.692882 399.5,25.5 L399.5,274.5 C399.5,288.30713 388.30713,299.5 374.5,299.5 L25.5,299.5 C11.692882,299.5 0.5,288.30713 0.5,274.5 z">

            <!--
            InkPresenter 可以包含子控件。本例为在 InkPresenter 的底部循环播放视频
            -->
            <MediaElement x:Name="mediaElement" Source="/Silverlight20;component/Video/Demo.wmv" Width="400" Height="100" Canvas.Top="200" Stretch="UniformToFill" MediaEnded="mediaElement_MediaEnded" />

        </InkPresenter>
    
        <!--红色取色点，点此后可画红色的线-->
        <Ellipse x:Name="ellipseRed" Canvas.Top="320" Canvas.Left="20" Cursor="Hand" Fill="Red" Width="20" Height="20" MouseLeftButtonDown="ellipseRed_MouseLeftButtonDown" />

        <!--黑色取色点，点此后可画黑色的线-->
        <Ellipse x:Name="ellipseBlack" Canvas.Top="320" Canvas.Left="50" Cursor="Hand" Fill="Black" Width="20" Height="20" MouseLeftButtonDown="ellipseBlack_MouseLeftButtonDown" />

        <!--橡皮擦，点此后可擦除之前画的线-->
        <Button x:Name="btnEraser" Canvas.Top="320" Canvas.Left="80" Content="橡皮擦" Click="btnEraser_Click" />

        <!--用于清除 InkPresenter 上的墨迹的按钮-->
        <Button x:Name="btnClear" Canvas.Top="320" Canvas.Left="130" Content="清除" Click="btnClear_Click" />

        <!--用于显示当前 Stroke（笔划） 所在的 矩形范围 的位置信息-->
        <TextBox x:Name="txtMsg" Canvas.Top="320" Canvas.Left="180" Width="220" />
           
    </Canvas>
</UserControl>

InkPresenter.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 System.Windows.Ink;
using System.Xml.Linq;
using System.ServiceModel;
using System.ServiceModel.Channels;

namespace Silverlight20.Interactive