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Windows 8 Store Apps学习（51） 输入: 涂鸦板2013-12-10 cnblogs webabcd介绍

通过 Pointer 相关事件实现一个具有基本功能的涂鸦板

通过 InkManager 实现一个功能完善的涂鸦板

示例

1、演示如何通过 Pointer 相关事件实现一个只有基本功能的涂鸦板

Input/Ink/Simple.xaml

<Pagex:Class="XamlDemo.Input.Ink.Simple"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:local="using:XamlDemo.Input.Ink"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"mc:Ignorable="d"><Grid Background="Transparent"><StackPanel Margin="120 0 0 0"><Button Name="btnClear" Content="清除" Click="btnClear_Click_1" /><Canvas Name="canvas" Background="Blue" Width="800" Height="480" HorizontalAlignment="Left" Margin="0 10 0 0" /></StackPanel></Grid></Page>

Input/Ink/Simple.xaml.cs

/* * 通过 Pointer 相关事件实现一个只有基本功能的涂鸦板 */using System;using System.Collections.Generic;using Windows.Foundation;using Windows.UI;using Windows.UI.Input;using Windows.UI.Xaml;using Windows.UI.Xaml.Controls;using Windows.UI.Xaml.Input;using Windows.UI.Xaml.Media;using Windows.UI.Xaml.Shapes;namespace XamlDemo.Input.Ink{public sealed partial class Simple : Page{// 用于保存触摸点（PointerId - Point）private Dictionary<uint, Point？> _dicPoint;public Simple（）{this.InitializeComponent（）;canvas.PointerPressed += canvas_PointerPressed;canvas.PointerMoved += canvas_PointerMoved;canvas.PointerReleased += canvas_PointerReleased;canvas.PointerExited += canvas_PointerExited;_dicPoint = new Dictionary<uint, Point？>（）;}void canvas_PointerPressed（object sender, PointerRoutedEventArgs e）{// 指针按下后，保存此触摸点PointerPoint pointerPoint = e.GetCurrentPoint（canvas）;_dicPoint[pointerPoint.PointerId] = pointerPoint.Position;}void canvas_PointerMoved（object sender, PointerRoutedEventArgs e）{PointerPoint pointerPoint = e.GetCurrentPoint（canvas）;if （_dicPoint.ContainsKey（pointerPoint.PointerId） && _dicPoint[pointerPoint.PointerId].HasValue）{Point currentPoint = pointerPoint.Position;Point previousPoint = _dicPoint[pointerPoint.PointerId].Value;// 如果指针移动过程中，两个点间的距离超过 4 则在两点间绘制一条直线，以完成涂鸦if （ComputeDistance（currentPoint, previousPoint） > 4）{Line line = new Line（）{X1 = previousPoint.X,Y1 = previousPoint.Y,X2 = currentPoint.X,Y2 = currentPoint.Y,StrokeThickness = 5,Stroke = new SolidColorBrush（Colors.Orange）,StrokeEndLineCap = PenLineCap.Round};_dicPoint[pointerPoint.PointerId] = currentPoint;canvas.Children.Add（line）;}}}void canvas_PointerReleased（object sender, PointerRoutedEventArgs e）{// 指针释放后，从字典中删除此 PointerId 的数据PointerPoint pointerPoint = e.GetCurrentPoint（canvas）;if （_dicPoint.ContainsKey（pointerPoint.PointerId））_dicPoint.Remove（pointerPoint.PointerId）;}void canvas_PointerExited（object sender, PointerRoutedEventArgs e）{// 指针离开相当于指针释放canvas_PointerReleased（sender, e）;}// 清除涂鸦private void btnClear_Click_1（object sender, RoutedEventArgs e）{canvas.Children.Clear（）;_dicPoint.Clear（）;}// 计算两个点（Point）之间的距离private double ComputeDistance（Point point1, Point point2）{return Math.Sqrt（Math.Pow（point1.X - point2.X, 2） + Math.Pow（point1.Y - point2.Y, 2））;}}}