InkCanvas基本操作（电子白板、画图）

    WPF的InkCanvas就是一个画板，可以在上面随意涂鸦，每写上一笔，InkCanvas的Strokes集合里就新增一个涂鸦对象，下面的代码演示了基本的操作。
效果图

 xaml代码
<Window x:Class=”WPF_InkCanvas.MainWindow”
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″
xmlns:local=”clr-namespace:WPF_InkCanvas”
mc:Ignorable=”d”
Title=”MainWindow” Height=”450″ Width=”800″>
<Grid>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition Height=”auto”/>
<RowDefinition Height=”auto”/>
</Grid.RowDefinitions>
<Image Name=”imgMeasure” HorizontalAlignment=”Center” Stretch=”Uniform”/>
<InkCanvas Name=”inkCanvasMeasure” EditingMode=”None” Background=”Transparent” HorizontalAlignment=”Center”
Width=”{Binding ElementName=imgMeasure, Path=ActualWidth}” Height=”{Binding ElementName=imgMeasure, Path=ActualHeight}”
>
<!–MouseDown=”InkCanvasMeasure_MouseDown” MouseMove=”InkCanvasMeasure_MouseMove”–>
<Label Content=”{Binding MeaInfo}” Background=”Transparent” HorizontalAlignment=”Left” VerticalAlignment=”Top” Margin=”10″
FontSize=”18″ Foreground=”Red” IsHitTestVisible=”False”/>
</InkCanvas>
<Grid Grid.Row=”1″>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<RadioButton Grid.Column=”0″ Content=”绘制墨迹” Click=”RadioButton_Click”/>
<RadioButton Grid.Column=”1″ Content=”按点擦除” Click=”RadioButton_Click”/>
<RadioButton Grid.Column=”2″ Content=”按线擦除” Click=”RadioButton_Click”/>
<RadioButton Grid.Column=”3″ Content=”选中墨迹” Click=”RadioButton_Click”/>
<RadioButton Grid.Column=”4″ Content=”停止操作” Click=”RadioButton_Click”/>
</Grid>
<StackPanel Grid.Row=”2″ Orientation=”Horizontal”>
<Button Content=”OpenFile” Margin=”5″ HorizontalAlignment=”Left” FontSize=”20″ Click=”OpenFile_Click”/>
<Button Content=”SaveInkCanvas” Margin=”5″ HorizontalAlignment=”Left” FontSize=”20″ Click=”SaveInkCanvas_Click”/>
<Button Content=”LoadInkCanvas” Margin=”5″ HorizontalAlignment=”Left” FontSize=”20″ Click=”LoadInkCanvas_Click”/>
<Button Content=”CopyInkCanvas” Margin=”5″ HorizontalAlignment=”Left” FontSize=”20″ Click=”CopyInkCanvas_Click”/>
<Button Content=”PasteInkCanvas” Margin=”5″ HorizontalAlignment=”Left” FontSize=”20″ Click=”PasteInkCanvas_Click”/>
</StackPanel>
</Grid>
</Window>
后台代码
using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WPF_InkCanvas
{
/// <summary>
/// MainWindow.xaml 的交互逻辑
/// </summary>
public partial class MainWindow : Window
{
ViewModel viewModel;
public MainWindow()
{
InitializeComponent();

DrawingAttributes drawingAttributes = new DrawingAttributes
{
Color = Colors.Red,
Width = 2,
Height = 2,
StylusTip = StylusTip.Rectangle,
FitToCurve = true,
IsHighlighter = false,
IgnorePressure = true,

};
inkCanvasMeasure.DefaultDrawingAttributes = drawingAttributes;

viewModel = new ViewModel
{
MeaInfo = “测试······”,
};

DataContext = viewModel;
}

private void InkCanvasMeasure_MouseDown(object sender, MouseButtonEventArgs e)
{

}

private void InkCanvasMeasure_MouseMove(object sender, MouseEventArgs e)
{

}

private void OpenFile_Click(object sender, RoutedEventArgs e)
{
OpenFileDialog openDialog = new OpenFileDialog
{
Filter = “Image Files (*.jpg)|*.jpg|Image Files (*.png)|*.png|Image Files (*.bmp)|*.bmp”,
Title = “Open Image File”
};
if (openDialog.ShowDialog() == true)
{
BitmapImage image = new BitmapImage();
image.BeginInit();
image.UriSource = new Uri(openDialog.FileName, UriKind.RelativeOrAbsolute);
image.EndInit();
imgMeasure.Source = image;
}
}

private void RadioButton_Click(object sender, RoutedEventArgs e)
{
if ((sender as RadioButton).Content.ToString() == “绘制墨迹”)
{
inkCanvasMeasure.EditingMode = InkCanvasEditingMode.Ink;
}

else if ((sender as RadioButton).Content.ToString() == “按点擦除”)
{
inkCanvasMeasure.EditingMode = InkCanvasEditingMode.EraseByPoint;
}

else if ((sender as RadioButton).Content.ToString() == “按线擦除”)
{
inkCanvasMeasure.EditingMode = InkCanvasEditingMode.EraseByStroke;
}

else if ((sender as RadioButton).Content.ToString() == “选中墨迹”)
{
inkCanvasMeasure.EditingMode = InkCanvasEditingMode.Select;
}

else if ((sender as RadioButton).Content.ToString() == “停止操作”)
{
inkCanvasMeasure.EditingMode = InkCanvasEditingMode.None;
}
}

private void SaveInkCanvas_Click(object sender, RoutedEventArgs e)
{
FileStream fileStream = new FileStream(“inkCanvas.isf”, FileMode.Create, FileAccess.ReadWrite);
inkCanvasMeasure.Strokes.Save(fileStream);
fileStream.Close();
}

private void LoadInkCanvas_Click(object sender, RoutedEventArgs e)
{
FileStream fileStream = new FileStream(“inkCanvas.isf”, FileMode.Open, FileAccess.Read);
inkCanvasMeasure.Strokes = new StrokeCollection(fileStream);
fileStream.Close();
}

private void CopyInkCanvas_Click(object sender, RoutedEventArgs e)
{
inkCanvasMeasure.CopySelection();
}
private void PasteInkCanvas_Click(object sender, RoutedEventArgs e)
{
inkCanvasMeasure.Paste();
}
}
}
ViewModel.cs代码
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WPF_InkCanvas
{
class ViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;

protected virtual void OnPropertyChanged(string propertyName = null)
{
if (PropertyChanged != null)
PropertyChanged.Invoke(this, new PropertyChangedEventArgs(propertyName));
}

private string meaInfo;
public string MeaInfo
{
get => meaInfo;
set
{
meaInfo = value;
OnPropertyChanged(“MeaInfo”);
}
}
}
}
    补充说明：将Image和InkCanvas放到一个Grid里，并且将InkCanvas的长宽绑定到Image，这样Image和InkCanvas的位置就是对应的，方便我后续在InkCanvas上提取Image的感兴趣区域；InkCanvas里加了一个Label可以实现类似图片上添加文字说明的功能，要设置Label的IsHitTestVisible=”False”，不然点击事件就没办法触发了。

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版权声明：本文为CSDN博主「Taosy1211」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/u012366767/article/details/81265922