Public Overridable Sub RedirectPaint( _
   ByVal graphics As Graphics, _
   ByVal src As Rectangle, _
   ByVal dest As Rectangle, _
   ByVal destClip As Rectangle, _
   ByVal transform As Matrix _
) 

Visual Basic (Usage)	Copy Code
Dim instance As RasterImageViewer Dim graphics As Graphics Dim src As Rectangle Dim dest As Rectangle Dim destClip As Rectangle Dim transform As Matrix   instance.RedirectPaint(graphics, src, dest, destClip, transform)

public virtual void RedirectPaint( 
   Graphics graphics,
   Rectangle src,
   Rectangle dest,
   Rectangle destClip,
   Matrix transform
)

public:
virtual void RedirectPaint( 
   Graphics graphics,
   Rectangle src,
   Rectangle dest,
   Rectangle destClip,
   Matrix transform
) 

Parameters

graphics

The Graphics object used to paint.

src

Rectangle which determines the portion of the image to paint.

dest

Rectangle which determines where the image is placed, and how it is scaled.

destClip

Rectangle which clips the image display.

transform

The matrix is used to transform from physical to logical coordinates

This example creates a Form with a RasterImageViewer and a panel. An image is loaded into the RasterImageViewer, and stationary and moving text are drawn on top of the image. A mirror image of RasterImageViewer contents is then painted on the panel.

Visual Basic

Copy Code

Private Class MyForm2 : Inherits Form     Private Class MyPanel : Inherits Panel         Protected Overrides Sub OnPaintBackground(ByVal pe As PaintEventArgs)             ' do nothing         End Sub     End Class     Private viewer As RasterImageViewer     Private panel As MyPanel     Public Sub New(ByVal title As String)         Text = title         Size = New Size(750, 450)         ' Create the raster viewer         viewer = New RasterImageViewer()         viewer.DoubleBuffer = True         viewer.Dock = DockStyle.Fill         ' Load an image into the viewer         RasterCodecs.Startup()         Dim codecs As RasterCodecs = New RasterCodecs()         viewer.Image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "Sample1.cmp")         codecs.Dispose()         RasterCodecs.Shutdown()         ' Create the panel         panel = New MyPanel()         panel.Parent = Me         panel.Width = 400         panel.Height = 400         panel.Dock = DockStyle.Right         panel.BackColor = Color.Beige         panel.BorderStyle = BorderStyle.Fixed3D         Controls.Add(panel)         panel.BringToFront()         Controls.Add(viewer)         viewer.BringToFront()         AddHandler panel.Paint, AddressOf panel_Paint         AddHandler viewer.PostImagePaint, AddressOf viewer_PostImagePaint         AddHandler viewer.RedirectImagePaint, AddressOf viewer_RedirectImagePaint     End Sub     Private Sub viewer_RedirectImagePaint(ByVal sender As Object, ByVal e As EventArgs)         panel.Invalidate()     End Sub     Private Sub panel_Paint(ByVal sender As Object, ByVal e As PaintEventArgs)         If Not viewer.Image Is Nothing Then             Dim dx As Integer = viewer.Image.Width \ 2             Dim dy As Integer = viewer.Image.Height \ 2             Dim dest As Rectangle = viewer.SourceRectangle             ' move center of image to origin             Dim m1 As Matrix = New Matrix(1, 0, 0, 1, -dx, -dy)             ' mirror the image             Dim m2 As Matrix = New Matrix(-1, 0, 0, 1, 0, 0)             m1.Multiply(m2, MatrixOrder.Append)             ' move back to original location             Dim m3 As Matrix = New Matrix(1, 0, 0, 1, dx, dy)             m1.Multiply(m3, MatrixOrder.Append)             ' scale image to fit on panel             Dim scaleX As Single = CSng(panel.Width) / CSng(viewer.Image.Width)             Dim scaleY As Single = CSng(panel.Height) / CSng(viewer.Image.Height)             Dim m4 As Matrix = New Matrix(scaleX, 0, 0, scaleY, 0, 0)             m1.Multiply(m4, MatrixOrder.Append)             ' display contents of RaserImageViewer on panel             viewer.RedirectPaint(e.Graphics, Rectangle.Empty, Rectangle.Empty, Rectangle.Empty, m1)         End If     End Sub     Private Sub viewer_PostImagePaint(ByVal sender As Object, ByVal e As PaintEventArgs)         Dim graphics As Graphics = e.Graphics         Dim graphicsState As GraphicsState = graphics.Save()         Dim font As Font = New Font("Arial", 16)         e.Graphics.DrawString("This text stays with the window", font, Brushes.Yellow, New PointF(100, 100))         graphics.MultiplyTransform(viewer.Transform)         e.Graphics.DrawString("This text stays with the image.", font, Brushes.White, New PointF(100, 200))         graphics.Restore(graphicsState)         graphics.Flush()     End Sub End Class Public Sub RasterImageViewer_RedirectPaint(ByVal title As String)     Dim form As MyForm2 = New MyForm2(title)     form.ShowDialog() End Sub

C#

Copy Code

class MyForm2 : Form  {     class MyPanel : Panel     {        protected override void  OnPaintBackground(PaintEventArgs pe)        {           // do nothing        }     }       RasterImageViewer viewer;     MyPanel panel;       public MyForm2(string title)     {        Text = title;        Size = new Size(750, 450);          // Create the raster viewer        viewer = new RasterImageViewer();        viewer.DoubleBuffer = true;        viewer.Dock = DockStyle.Fill;          // Load an image into the viewer        RasterCodecs.Startup();        RasterCodecs codecs = new RasterCodecs();        viewer.Image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "Sample1.cmp");        codecs.Dispose();        RasterCodecs.Shutdown();          // Create the panel        panel = new MyPanel();        panel.Parent = this;        panel.Width = 400;        panel.Height = 400;        panel.Dock = DockStyle.Right;        panel.BackColor = Color.Beige;        panel.BorderStyle = BorderStyle.Fixed3D;          Controls.Add(panel);        panel.BringToFront();          Controls.Add(viewer);        viewer.BringToFront();          panel.Paint += new PaintEventHandler(panel_Paint);        viewer.PostImagePaint += new PaintEventHandler(viewer_PostImagePaint);        viewer.RedirectImagePaint += new EventHandler(viewer_RedirectImagePaint);     }       void viewer_RedirectImagePaint(object sender, EventArgs e)     {        panel.Invalidate();     }       void panel_Paint(object sender, PaintEventArgs e)     {        if(viewer.Image != null)        {           int dx = viewer.Image.Width / 2;           int dy = viewer.Image.Height / 2;           Rectangle dest = viewer.SourceRectangle;             // move center of image to origin           Matrix m1 = new Matrix(1,0,0,1,-dx,-dy);             // mirror the image           Matrix m2 = new Matrix(-1, 0, 0, 1, 0, 0);           m1.Multiply(m2, MatrixOrder.Append);             // move back to original location           Matrix m3 = new Matrix(1, 0, 0, 1, dx, dy);           m1.Multiply(m3, MatrixOrder.Append);             // scale image to fit on panel           float scaleX = (float)panel.Width / (float)viewer.Image.Width;           float scaleY = (float)panel.Height / (float)viewer.Image.Height;           Matrix m4 = new Matrix(scaleX, 0, 0, scaleY, 0, 0);           m1.Multiply(m4, MatrixOrder.Append);             // display contents of RaserImageViewer on panel           viewer.RedirectPaint(              e.Graphics,              Rectangle.Empty, //_viewer.SourceRectangle,              Rectangle.Empty,              Rectangle.Empty, //e.ClipRectangle,               m1);        }     }       private void viewer_PostImagePaint(object sender, PaintEventArgs e)     {        Graphics graphics = e.Graphics;        GraphicsState graphicsState = graphics.Save();          Font font = new Font("Arial", 16);        e.Graphics.DrawString("This text stays with the window", font, Brushes.Yellow, new PointF(100,100));          graphics.MultiplyTransform(viewer.Transform);        e.Graphics.DrawString("This text stays with the image.", font, Brushes.White, new PointF(100,200));          graphics.Restore(graphicsState);        graphics.Flush();     }  }    public void RasterImageViewer_RedirectPaint(string title)  {     MyForm2 form = new MyForm2(title);     form.ShowDialog();  }

Use this function to paint the contents of the RasterImageViewer onto any Graphics object. The contents of the RasterImageViewer includes the Image and anything painted in the PostImagePaint event handler. When using this function, pass either a valid transform or a dest rectangle, but NOT BOTH. It is an error to pass both a transform and a dest rectangle.

If you pass a transformmatrix, it is applied to the graphics object before any painting takes place. If you pass a dest rectangle, internally a transform is constructed from src and dest and it is applied to the graphics object before any painting takes place. Passing Rectangle.Empty for the src rectangle gives the default, which is equivalent to the size of the Image. Passing Rectangle.Empty for the destClip rectangle is equivalent to passing same Rectangle as dst. Passing null for the transform argument means that src and dest are used to create a transform.

Target Platforms: Microsoft .NET Framework 2.0, Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

Reference