WPF实现截图（仿微信截图）

using Microsoft.Win32; using System; using System.Collections.Generic; using System.Drawing.Drawing2D; using System.Drawing.Text; using System.Linq; using System.Text; using System.Windows; using System.Windows.Controls; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Shapes;  namespace WPFDevelopers.Controls {     [TemplatePart(Name = CanvasTemplateName, Type = typeof(Canvas))]     [TemplatePart(Name = RectangleLeftTemplateName, Type = typeof(Rectangle))]     [TemplatePart(Name = RectangleTopTemplateName, Type = typeof(Rectangle))]     [TemplatePart(Name = RectangleRightTemplateName, Type = typeof(Rectangle))]     [TemplatePart(Name = RectangleBottomTemplateName, Type = typeof(Rectangle))]     [TemplatePart(Name = BorderTemplateName, Type = typeof(Border))]     [TemplatePart(Name = WrapPanelTemplateName, Type = typeof(WrapPanel))]     [TemplatePart(Name = ButtonSaveTemplateName, Type = typeof(Button))]     [TemplatePart(Name = ButtonCancelTemplateName, Type = typeof(Button))]     [TemplatePart(Name = ButtonCompleteTemplateName, Type = typeof(Button))]      public class ScreenCut : Window     {         private const string CanvasTemplateName = "PART_Canvas";         private const string RectangleLeftTemplateName = "PART_RectangleLeft";         private const string RectangleTopTemplateName = "PART_RectangleTop";         private const string RectangleRightTemplateName = "PART_RectangleRight";         private const string RectangleBottomTemplateName = "PART_RectangleBottom";         private const string BorderTemplateName = "PART_Border";         private const string WrapPanelTemplateName = "PART_WrapPanel";         private const string ButtonSaveTemplateName = "PART_ButtonSave";         private const string ButtonCancelTemplateName = "PART_ButtonCancel";         private const string ButtonCompleteTemplateName = "PART_ButtonComplete";          private Canvas _canvas;         private Rectangle _rectangleLeft, _rectangleTop, _rectangleRight, _rectangleBottom;         private Border _border;         private WrapPanel _wrapPanel;         private Button _buttonSave,_buttonCancel, _buttonComplete;         private Rect rect;         private Point pointStart, pointEnd;         private bool isMouseUp = false;          static ScreenCut()         {             DefaultStyleKeyProperty.OverrideMetadata(typeof(ScreenCut), new FrameworkPropertyMetadata(typeof(ScreenCut)));         }         public override void OnApplyTemplate()         {             base.OnApplyTemplate();             _canvas = GetTemplateChild(CanvasTemplateName) as Canvas;             _rectangleLeft = GetTemplateChild(RectangleLeftTemplateName) as Rectangle;             _rectangleTop = GetTemplateChild(RectangleTopTemplateName) as Rectangle;             _rectangleRight = GetTemplateChild(RectangleRightTemplateName) as Rectangle;             _rectangleBottom = GetTemplateChild(RectangleBottomTemplateName) as Rectangle;             _border = GetTemplateChild(BorderTemplateName) as Border;             _wrapPanel = GetTemplateChild(WrapPanelTemplateName) as WrapPanel;             _buttonSave = GetTemplateChild(ButtonSaveTemplateName) as Button;             if (_buttonSave != null)                 _buttonSave.Click += _buttonSave_Click;             _buttonCancel = GetTemplateChild(ButtonCancelTemplateName) as Button;             if (_buttonCancel != null)                 _buttonCancel.Click += _buttonCancel_Click;             _buttonComplete = GetTemplateChild(ButtonCompleteTemplateName) as Button;             if (_buttonComplete != null)                 _buttonComplete.Click += _buttonComplete_Click;             this._canvas.Background = new ImageBrush(ChangeBitmapToImageSource(CaptureScreen()));             _rectangleLeft.Width = _canvas.Width;             _rectangleLeft.Height = _canvas.Height;         }          private void _buttonSave_Click(object sender, RoutedEventArgs e)         {             SaveFileDialog dlg = new SaveFileDialog();             dlg.FileName = $"WPFDevelopers{DateTime.Now.ToString("yyyyMMddHHmmss")}.jpg";             dlg.DefaultExt = ".jpg";             dlg.Filter = "image file|*.jpg";              if (dlg.ShowDialog() == true)             {                 BitmapEncoder pngEncoder = new PngBitmapEncoder();                 pngEncoder.Frames.Add(BitmapFrame.Create(CutBitmap()));                 using (var fs = System.IO.File.OpenWrite(dlg.FileName))                 {                     pngEncoder.Save(fs);                     fs.Dispose();                     fs.Close();                 }             }             Close();         }          private void _buttonComplete_Click(object sender, RoutedEventArgs e)         {                         Clipboard.SetImage(CutBitmap());             Close();         }         CroppedBitmap CutBitmap()         {             var renderTargetBitmap = new RenderTargetBitmap((int)_canvas.Width,   (int)_canvas.Height, 96d, 96d, System.Windows.Media.PixelFormats.Default);             renderTargetBitmap.Render(_canvas);             return  new CroppedBitmap(renderTargetBitmap, new Int32Rect((int)rect.X, (int)rect.Y, (int)rect.Width, (int)rect.Height));         }         private void _buttonCancel_Click(object sender, RoutedEventArgs e)         {             Close();         }          protected override void OnPreviewKeyDown(KeyEventArgs e)         {             if (e.Key == Key.Escape)                 Close();         }          protected override void OnPreviewMouseLeftButtonDown(MouseButtonEventArgs e)         {             if (!isMouseUp)             {                 _wrapPanel.Visibility = Visibility.Hidden;                 pointStart = e.GetPosition(_canvas);                 pointEnd = pointStart;                 rect = new Rect(pointStart, pointEnd);             }          }         protected override void OnPreviewMouseMove(MouseEventArgs e)         {             if (e.LeftButton == MouseButtonState.Pressed && !isMouseUp)             {                 var current = e.GetPosition(_canvas);                 MoveAllRectangle(current);             }         }         protected override void OnPreviewMouseLeftButtonUp(MouseButtonEventArgs e)         {             if (!isMouseUp)             {                 _wrapPanel.Visibility = Visibility.Visible;                 Canvas.SetLeft(this._wrapPanel, rect.X + rect.Width - this._wrapPanel.ActualWidth);                 Canvas.SetTop(this._wrapPanel, rect.Y + rect.Height + 4);                 isMouseUp = true;             }         }          void MoveAllRectangle(Point current)         {             pointEnd = current;             rect = new Rect(pointStart, pointEnd);             this._rectangleLeft.Width = rect.X;             this._rectangleLeft.Height = _canvas.Height;              Canvas.SetLeft(this._rectangleTop, this._rectangleLeft.Width);             this._rectangleTop.Width = rect.Width;             double h = 0.0;             if (current.Y < pointStart.Y)                 h = current.Y;             else                 h = current.Y - rect.Height;             this._rectangleTop.Height = h;              Canvas.SetLeft(this._rectangleRight, this._rectangleLeft.Width + rect.Width);             this._rectangleRight.Width = _canvas.Width - (rect.Width + this._rectangleLeft.Width);             this._rectangleRight.Height = _canvas.Height;              Canvas.SetLeft(this._rectangleBottom, this._rectangleLeft.Width);             Canvas.SetTop(this._rectangleBottom, rect.Height + this._rectangleTop.Height);             this._rectangleBottom.Width = rect.Width;             this._rectangleBottom.Height = _canvas.Height - (rect.Height + this._rectangleTop.Height);              this._border.Height = rect.Height;             this._border.Width = rect.Width;             Canvas.SetLeft(this._border, rect.X);             Canvas.SetTop(this._border, rect.Y);         }                 System.Drawing.Bitmap CaptureScreen()         {             var bmpCaptured = new System.Drawing.Bitmap((int)SystemParameters.PrimaryScreenWidth, (int)SystemParameters.PrimaryScreenHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);             using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bmpCaptured))             {                 g.SmoothingMode = SmoothingMode.AntiAlias;                 g.CompositingQuality = CompositingQuality.HighQuality;                 g.InterpolationMode = InterpolationMode.HighQualityBicubic;                 g.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;                 g.PixelOffsetMode = PixelOffsetMode.HighQuality;                  g.CopyFromScreen(0, 0, 0, 0, bmpCaptured.Size, System.Drawing.CopyPixelOperation.SourceCopy);             }             return bmpCaptured;         }          [System.Runtime.InteropServices.DllImport("gdi32.dll")]         public static extern bool DeleteObject(IntPtr hObject);         ImageSource ChangeBitmapToImageSource(System.Drawing.Bitmap bitmap)         {             IntPtr hBitmap = bitmap.GetHbitmap();             ImageSource wpfBitmap = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(                 hBitmap,                 IntPtr.Zero,                 Int32Rect.Empty,                 BitmapSizeOptions.FromEmptyOptions());              if (!DeleteObject(hBitmap))             {                 throw new System.ComponentModel.Win32Exception();             }             return wpfBitmap;         }     } }

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"                     xmlns:controls="clr-namespace:WPFDevelopers.Controls">          <ResourceDictionary.MergedDictionaries>         <ResourceDictionary Source="Basic/ControlBasic.xaml"/>         <ResourceDictionary Source="../Styles/Styles.Buttons.xaml"/>     </ResourceDictionary.MergedDictionaries>      <Style x:Key="RectangleStyle" TargetType="{x:Type Rectangle}">         <Setter Property="Fill" Value="{StaticResource BlackSolidColorBrush}"/>         <Setter Property="Opacity" Value=".5"/> </Style>          <Style TargetType="{x:Type controls:ScreenCut}" BasedOn="{StaticResource ControlBasicStyle}">         <Setter Property="WindowState" Value="Maximized"/>         <Setter Property="WindowStyle" Value="None"/>         <Setter Property="Template">             <Setter.Value>                 <ControlTemplate TargetType="{x:Type controls:ScreenCut}">                     <Canvas x:Name="PART_Canvas"             Width="{Binding Source={x:Static SystemParameters.PrimaryScreenWidth}}"             Height="{Binding Source={x:Static SystemParameters.PrimaryScreenHeight}}">                         <Rectangle x:Name="PART_RectangleLeft" Style="{StaticResource RectangleStyle}"/>                         <Rectangle x:Name="PART_RectangleTop" Style="{StaticResource RectangleStyle}"/>                         <Rectangle x:Name="PART_RectangleRight" Style="{StaticResource RectangleStyle}"/>                         <Rectangle x:Name="PART_RectangleBottom" Style="{StaticResource RectangleStyle}"/>                         <Border x:Name="PART_Border" BorderBrush="{StaticResource SuccessPressedSolidColorBrush}"                                  BorderThickness="1"/>                         <WrapPanel x:Name="PART_WrapPanel"                                     Visibility="Hidden" Panel.ZIndex="99"                                    Height="38" Background="{StaticResource WhiteSolidColorBrush}"                                    VerticalAlignment="Center">                             <Button x:Name="PART_ButtonSave" Style="{StaticResource PathButton}"                                     ToolTip="保存" Margin="10,0,0,0">                                 <Button.Content>                                     <Path Fill="{StaticResource InfoPressedSolidColorBrush}"                                            Width="18" Height="18" Stretch="Fill"                                            Data="{StaticResource PathSave}"/>                                 </Button.Content>                             </Button>                             <Button x:Name="PART_ButtonCancel" Style="{StaticResource PathButton}"                                     ToolTip="取消">                                 <Button.Content>                                     <Path Fill="{StaticResource DangerPressedSolidColorBrush}"                                            Width="14" Height="14" Stretch="Fill"                                            Data="{StaticResource PathCancel}"/>                                 </Button.Content>                             </Button>                             <Button x:Name="PART_ButtonComplete"  Style="{StaticResource PathButton}"                                     ToolTip="完成" Margin="0,0,10,0">                                 <Button.Content>                                     <Path Fill="{StaticResource SuccessPressedSolidColorBrush}"                                             Width="20" Height="15" Stretch="Fill"                                            Data="{StaticResource PathComplete}"/>                                 </Button.Content>                             </Button>                         </WrapPanel>                      </Canvas>                 </ControlTemplate>             </Setter.Value>         </Setter> </Style> </ResourceDictionary>

 var screenCut = new ScreenCut();    screenCut.ShowDialog();