<InkCanvas Grid.Column="1" Grid.Row="1" Background="White" Height="240" Name="ink"><InkCanvas.DefaultDrawingAttributes><DrawingAttributes Color="#FF000000" StylusTip="Ellipse" Height="6" Width="6" IgnorePressure="False" FitToCurve="False"><!--调整画笔形状--><DrawingAttributes.StylusTipTransform><!--https://msdn.microsoft.com/library/system.windows.media.matrix(v=vs.110).aspx--><Matrix M11="1" M12="0" M21="0" M22="1" OffsetX="0" OffsetY="0"/></DrawingAttributes.StylusTipTransform></DrawingAttributes></InkCanvas.DefaultDrawingAttributes>
</InkCanvas>

<Button x:Name="btnClearSign" HorizontalAlignment="Left" VerticalAlignment="Top" Width="100" Padding="0" Margin="12,6,0,0" Click="btnClearSign_Click"><Button.Template><ControlTemplate><Grid><Label Cursor="Hand" Foreground="Red" FontFamily="Microsoft YaHei UI" FontSize="20"><Underline><Run Text="清除签名"></Run></Underline></Label></Grid></ControlTemplate></Button.Template>
</Button>

ink.Strokes.Clear();

// 判断签名板内是否有内容
if (ink.Strokes.Any())
{// 让用户自己选择文件夹保存// 需要在工程中添加对System.Windows.Forms的引用// References => Add Reference => 勾选 System.Windows.Forms 项 => OKvar folderPicker = new FolderBrowserDialog();var res = folderPicker.ShowDialog();// 判断用户有没有选中文件夹if (res == System.Windows.Forms.DialogResult.Cancel) return;// 文件保存路径var folderPath = folderPicker.SelectedPath;var fileName = DateTime.Now.ToString("yyyyMMddHHmmss");var fileUri = folderPath + "\\" + fileName + ".png";// windows系统下默认dpi貌似为96，但目前本机测试认为dpi设置为72较为合适// dpi的大小会直接影响签名保存结果是否完整，关于dpi的知识网上还是比较多的，请各位自行了解// 下一行代码的第三个参数用于确定位图的横向dpi，第四个参数为纵向dpivar renderBitmap = new RenderTargetBitmap((int)ink.ActualWidth, (int)ink.ActualHeight, 72d, 72d, PixelFormats.Pbgra32);renderBitmap.Render(ink);using (var stream = new FileStream(fileUri, FileMode.Create)){var encoder = new PngBitmapEncoder();encoder.Frames.Add(BitmapFrame.Create(renderBitmap));encoder.Save(stream);}undoList.Clear();// 打开签名文件所在位置
    FileUtil.LocateFile(fileUri);
}
else
{System.Windows.MessageBox.Show("尚未进行签名，不能执行保存操作！");
}

Stack<Stroke> undoList = new Stack<Stroke>();

private void MainWindow_Loaded(object sender, RoutedEventArgs e)
{this.KeyDown += (s, args) =>{// Undo => 检测 Ctrl + Zif((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control && args.Key == Key.Z){if (ink.Strokes.Any()){undoList.Push(ink.Strokes[ink.Strokes.Count - 1]);ink.Strokes.RemoveAt(ink.Strokes.Count - 1);}}// Redo => 检测 Ctrl + Yif ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control && args.Key == Key.Y){if (undoList.Any()){ink.Strokes.Add(undoList.Pop());}}};
}

public static class FileUtil
{/// <summary>/// 依据给定文件路径，打开文件位置并选中/// </summary>/// <param name="path">文件完全路径</param>public static void LocateFile(string path){/* // 此方法会导致每次新开一个文件资源管理器窗口，不喜欢* string domain = "";* var psi = new ProcessStartInfo("Explorer.exe");* psi.Arguments = "/c,/select," + path;* domain = psi.Domain;* var p = Process.Start(psi);*/IntPtr ppidl = IntPtr.Zero;uint psfgaoOut;FileManager.SHParseDisplayName(path, IntPtr.Zero, out ppidl, 0, out psfgaoOut);var res = FileManager.OpenFolderAndSelectItems(ppidl, 0, IntPtr.Zero, 0);}class FileManager{[DllImport("shell32.dll", EntryPoint = "SHOpenFolderAndSelectItems")]public static extern long OpenFolderAndSelectItems(IntPtr pidlFolder, UInt32 cidl, IntPtr apidl, UInt32 dwFlags);[DllImport("shell32.dll", EntryPoint = "SHParseDisplayName")]public static extern void SHParseDisplayName([MarshalAs(UnmanagedType.LPWStr)] string name, IntPtr bindingContext, [Out()] out IntPtr pidl, uint sfgaoIn, [Out()] out uint psfgaoOut);}
}