背水一战 Windows 10 (60) - 控件（媒体类）: Pointer 涂鸦板, InkCanvas 涂鸦板

原文:背水一战 Windows 10 (60) - 控件（媒体类）: Pointer 涂鸦板, InkCanvas 涂鸦板[源码下载]

[align=center]背水一战 Windows 10 (60) - 控件（媒体类）: Pointer 涂鸦板, InkCanvas 涂鸦板[/align]

作者：webabcd

介绍
背水一战 Windows 10 之 控件（媒体类）

通过处理 Pointer 相关事件实现一个简单的涂鸦板

InkCanvas 基础知识

示例
1、演示如何通过 Pointer 相关事件的处理，来实现一个简单的涂鸦板
Controls/MediaControl/InkSimple.xaml

<Page
x:Class="Windows10.Controls.MediaControl.InkSimple"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Windows10.Controls.MediaControl"
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="10 0 10 10">

<Button Name="btnClear" Content="清除" Click="btnClear_Click" Margin="5" />

<Canvas Name="canvas" Background="Blue" Width="800" Height="480" HorizontalAlignment="Left" Margin="5" />

</StackPanel>
</Grid>
</Page>

Controls/MediaControl/InkSimple.xaml.cs

/*
* 本例用于演示如何通过 Pointer 相关事件的处理，来实现一个简单的涂鸦板
*/

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 Windows10.Controls.MediaControl
{
public sealed partial class InkSimple : Page
{
// 用于保存触摸点（PointerId - Point）
private Dictionary<uint, Point?> _dicPoint;

public InkSimple()
{
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(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));
}
}
}

2、演示 InkCanvas 基础知识
Controls/MediaControl/InkCanvasDemo1.xaml

<Page
x:Class="Windows10.Controls.MediaControl.InkCanvasDemo1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Windows10.Controls.MediaControl"
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="10 0 10 10">

<Border Background="White" Width="480" Height="320" Margin="5" HorizontalAlignment="Left">
<!--
InkCanvas - 涂鸦板控件
-->
<InkCanvas Name="inkCanvas" />
</Border>

<ComboBox Name="drawingColor" Header="Color" SelectedIndex="0" SelectionChanged="UpdateDefaultDrawingAttributes_Handler" Margin="5">
<x:String>Red</x:String>
<x:String>Green</x:String>
<x:String>Blue</x:String>
</ComboBox>
<Slider Name="drawingSize" Foreground="Orange" Background="Red" Style="{StaticResource MySliderStyle}" Header="Size" Minimum="1" Maximum="20" Value="5" ValueChanged="UpdateDefaultDrawingAttributes_Handler" Margin="5" />
<CheckBox Name="drawingDrawAsHighlighter" Content="DrawAsHighlighter" IsChecked="False" Checked="UpdateDefaultDrawingAttributes_Handler" Unchecked="UpdateDefaultDrawingAttributes_Handler" Margin="5" />
<CheckBox Name="drawingFitToCurve" Content="FitToCurve" IsChecked="True" Checked="UpdateDefaultDrawingAttributes_Handler" Unchecked="UpdateDefaultDrawingAttributes_Handler" Margin="5" />
<ToggleSwitch Name="drawingPenTip" Style="{StaticResource MyToggleSwitchStyle}" OnContent="PenTipShape.Circle" OffContent="PenTipShape.Rectangle" IsOn="True" Toggled="UpdateDefaultDrawingAttributes_Handler" Margin="5" />
<CheckBox Name="drawingPenTipTransform" Content="通过 PenTipTransform 转换 PenTip 来实现笔尖形状的自定义" IsChecked="False" Checked="UpdateDefaultDrawingAttributes_Handler" Unchecked="UpdateDefaultDrawingAttributes_Handler" Margin="5" />
<CheckBox Name="chkErasing" Content="将输入指定为擦除模式" IsChecked="False" Checked="UpdateDefaultDrawingAttributes_Handler" Unchecked="UpdateDefaultDrawingAttributes_Handler" Margin="5" />
<CheckBox Name="chkIsInputEnabled" Content="IsInputEnabled" IsChecked="True" Checked="UpdateDefaultDrawingAttributes_Handler" Unchecked="UpdateDefaultDrawingAttributes_Handler" Margin="5" />
<Button Name="buttonClear" Content="全部清除"  Click="buttonClear_Click" />

</StackPanel>
</Grid>
</Page>

Controls/MediaControl/InkCanvasDemo1.xaml.cs

/*
* InkCanvas - 涂鸦板控件（继承自 FrameworkElement, 请参见 /Controls/BaseControl/FrameworkElementDemo/）
*     InkPresenter - 获取 InkPresenter 对象
*
* InkPresenter - 涂鸦板
*     IsInputEnabled - 是否启用涂鸦板
*     InputDeviceTypes - 输入设备的类型（None, Touch, Pen, Mouse）
*     InputProcessingConfiguration.Mode - 输入模式（None, Inking, Erasing）
*     CopyDefaultDrawingAttributes() - 获取 InkDrawingAttributes 对象
*     UpdateDefaultDrawingAttributes(InkDrawingAttributes value) - 设置 InkDrawingAttributes 对象
*
* InkDrawingAttributes - 涂鸦笔尖属性
*     IgnorePressure - 是否忽略触摸压力
*     Color - 笔尖的颜色
*     Size - 笔尖的尺寸（宽和高）
*     DrawAsHighlighter - 覆盖之前的涂鸦时（false - 直接覆盖；true - 高亮显示覆盖区域）
*     FitToCurve - 涂鸦时（true - 使用贝塞尔曲线生成涂鸦；false - 使用直线生成涂鸦）
*     PenTip - 笔尖的形状（Circle, Rectangle）
*     PenTipTransform - 用于转换 PenTip 的 Matrix3x2 仿射转换矩阵（Matrix3x2 提供了一些简便的方法：CreateRotation, CreateScale, CreateSkew, CreateTranslation 等）。通过它可以自定义笔尖的形状
*/

using System.Numerics;
using Windows.Foundation;
using Windows.UI;
using Windows.UI.Core;
using Windows.UI.Input.Inking;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

namespace Windows10.Controls.MediaControl
{
public sealed partial class InkCanvasDemo1 : Page
{
private InkPresenter _inkPresenter;

public InkCanvasDemo1()
{
this.InitializeComponent();

_inkPresenter = inkCanvas.InkPresenter;
_inkPresenter.InputDeviceTypes = CoreInputDeviceTypes.Mouse | CoreInputDeviceTypes.Pen | CoreInputDeviceTypes.Touch;

UpdateDefaultDrawingAttributes();
}

private void UpdateDefaultDrawingAttributes_Handler(object sender, RoutedEventArgs e)
{
UpdateDefaultDrawingAttributes();
}

private void buttonClear_Click(object sender, RoutedEventArgs e)
{
_inkPresenter.StrokeContainer.Clear();
}

private void UpdateDefaultDrawingAttributes()
{
if (_inkPresenter != null)
{
InkDrawingAttributes drawingAttributes = _inkPresenter.CopyDefaultDrawingAttributes();
drawingAttributes.IgnorePressure = true;

switch (drawingColor.SelectedValue.ToString())
{
case "Red":
drawingAttributes.Color = Colors.Red;
break;
case "Green":
drawingAttributes.Color = Colors.Green;
break;
case "Blue":
drawingAttributes.Color = Colors.Blue;
break;
}

drawingAttributes.Size = new Size(drawingSize.Value, drawingSize.Value);
drawingAttributes.DrawAsHighlighter = drawingDrawAsHighlighter.IsChecked.Value;
drawingAttributes.FitToCurve = drawingFitToCurve.IsChecked.Value;
drawingAttributes.PenTip = drawingPenTip.IsOn ? PenTipShape.Circle : PenTipShape.Rectangle;

if (drawingPenTipTransform.IsChecked == true)
drawingAttributes.PenTipTransform = Matrix3x2.CreateSkew(4, 4);
else
drawingAttributes.PenTipTransform = Matrix3x2.Identity;

_inkPresenter.UpdateDefaultDrawingAttributes(drawingAttributes);

if (chkErasing.IsChecked == true)
_inkPresenter.InputProcessingConfiguration.Mode = InkInputProcessingMode.Erasing;
else
_inkPresenter.InputProcessingConfiguration.Mode = InkInputProcessingMode.Inking;

_inkPresenter.IsInputEnabled = chkIsInputEnabled.IsChecked.Value;
}
}
}
}

OK
[源码下载]