Leadtools.WinForms Namespace > RasterImageViewer Class : RedirectPaint Method |
public virtual void RedirectPaint( Graphics graphics, Rectangle src, Rectangle dest, Rectangle destClip, Matrix transform )
'Declaration Public Overridable Sub RedirectPaint( _ ByVal graphics As Graphics, _ ByVal src As Rectangle, _ ByVal dest As Rectangle, _ ByVal destClip As Rectangle, _ ByVal transform As Matrix _ )
'Usage 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 )
Use this function to paint the contents of the RasterImageViewer onto any System.Drawing.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 System.Drawing.Rectangle as dst. Passing null for the transform argument means that src and dest are used to create a transform.
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 Dim codecs As RasterCodecs = New RasterCodecs() viewer.Image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Sample1.cmp")) codecs.Dispose() ' 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 Public NotInheritable Class LEAD_VARS Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images" End Class
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 codecs = new RasterCodecs(); viewer.Image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Sample1.cmp")); codecs.Dispose(); // 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(); } static class LEAD_VARS { public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images"; }
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2