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
) 

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("C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\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#

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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(@"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\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