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PaintBuffer(RasterImage,Graphics,LeadRect,LeadRect,LeadRect,LeadRect,byte[],int,int,int,RasterPaintProperties) Method

Summary

Paints image data from a buffer into a System.Drawing.Graphics object.

Syntax

C#
VB
C++
Public Overloads Shared Sub PaintBuffer( _ 
   ByVal image As Leadtools.RasterImage, _ 
   ByVal graphics As Graphics, _ 
   ByVal srcRect As Leadtools.LeadRect, _ 
   ByVal srcClipRect As Leadtools.LeadRect, _ 
   ByVal destRect As Leadtools.LeadRect, _ 
   ByVal destClipRect As Leadtools.LeadRect, _ 
   ByVal buffer() As Byte, _ 
   ByVal bufferOffset As Integer, _ 
   ByVal row As Integer, _ 
   ByVal count As Integer, _ 
   ByVal properties As Leadtools.Drawing.RasterPaintProperties _ 
)  

Parameters

image
The source image.

graphics
The destination System.Drawing.Graphics object where the image data will be displayed.

srcRect
A Leadtools.LeadRect object that specifies the part of the image to use as the display source.

The coordinates in the srcRect rectangle are relative to the image. You can pass Rectangle.Empty to use the default, which matches the image.

srcClipRect
A Leadtools.LeadRect object specifies the portion of the display source to paint. Generally, this is used for updating the display when part of the source image has changed.

The coordinates in the srcClipRect rectangle are relative to the image. You can pass Rectangle.Empty to use the default, which matches the image

destRect
A Leadtools.LeadRect object that determines how the source rectangle is scaled and how the image is positioned in the destination graphics object.

The coordinates in the destRect object are relative to the graphics object. There is no default for this parameter. You must specify the Leadtools.LeadRect object.

destClipRect
A Leadtools.LeadRect object that specifies the portion of the display rectangle to paint. Generally, this is used for updating changes in the display surface, such as when a user moves another window, uncovering a part of the image that had been covered up.

The coordinates in the destClipRect are relative to the System.Drawing.Graphics object. You can pass Rectangle.Empty to use the default, which matches the System.Drawing.Graphics object. In most cases, however, you should use the rectangle returned by the .NET PaintEventArgs.ClipRectangle or Windows WM_PAINT message.

buffer
The buffer that contains the image data to paint

bufferOffset
Offset into buffer where the data starts.

row
The first row to paint. The painted portion of any row may be limited by the rectangle parameters.

count
The number of rows to paint. The painted portion of any row may be limited by the rectangle parameters.

If the image data in buffer is compressed 1-bit data, you can specify the number of lines as a negative value (-lines), as explained in Speeding Up 1-Bit Documents.

properties
Options for the display.

Remarks

If the graphics object has fewer colors than the image, this method dithers the output to that display surface without affecting the actual image data.

If destRect is larger or smaller than the image's actual dimensions, then the image will be scaled to fit destRect.

If the image data in buffer is compressed 1-bit data, you can specify the number of lines as a negative value (- row), as explained in Speeding Up 1-Bit Documents.

The following properties are used from this Leadtools.RasterImage:

Except for the buffer specifications, this method uses source and destination rectangles the same as Paint(rasterimage,graphics,leadrect,rasterpaintproperties). For a complete explanation, refer to Paint(rasterimage,graphics,leadrect,rasterpaintproperties).

You can call PaintBuffer(rasterimage,graphics,leadrect,leadrect,leadrect,leadrect,byte[],int32,int32,int32,rasterpaintproperties) from a callback procedure to paint an image while it is being loaded.

For more information refer to RasterImage and GDI/GDI+.

For more information, refer to Changing Image Coordinates.

For more information, refer to Handling Palette Changes.

Example

C#
VB
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Drawing; 
using Leadtools.ImageProcessing; 
 
public void PaintBufferExample() 
{ 
   PaintBufferForm f = new PaintBufferForm(); 
   f.ShowDialog(); 
} 
 
class PaintBufferForm : Form 
{ 
   private RasterImage image; 
 
   public PaintBufferForm() 
   { 
      // Load the image 
      RasterCodecs codecs = new RasterCodecs(); 
 
      string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"); 
      image = codecs.Load(srcFileName); 
 
      Text = "PaintBuffer Example"; 
   } 
 
   protected override void Dispose(bool disposing) 
   { 
      // Clean up 
      if (disposing) 
      { 
         image.Dispose(); 
      } 
 
      base.Dispose(disposing); 
   } 
 
   protected override void OnPaint(PaintEventArgs e) 
   { 
      // Draw the image fit and center on this form 
      LeadRect destRect = LeadRect.FromLTRB(ClientRectangle.Left, ClientRectangle.Top, ClientRectangle.Right, ClientRectangle.Bottom); 
      destRect = RasterImage.CalculatePaintModeRectangle( 
         image.ImageWidth, 
         image.ImageHeight, 
         destRect, 
         RasterPaintSizeMode.Fit, 
         RasterPaintAlignMode.Center, 
         RasterPaintAlignMode.Center); 
 
      byte[] buffer = new byte[image.BytesPerLine]; 
 
      image.Access(); 
      for (int row = 0; row < image.Height; row++) 
      { 
         image.GetRow(row, buffer, 0, image.BytesPerLine); 
         RasterImagePainter.PaintBuffer(image, e.Graphics, LeadRect.Empty, LeadRect.Empty, destRect, LeadRect.Empty, buffer, 0, row, 1, RasterPaintProperties.Default); 
         Thread.Sleep(10); 
      } 
      image.Release(); 
 
      base.OnPaint(e); 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images"; 
} 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.Drawing 
Imports Leadtools.ImageProcessing 
 
Public Sub PaintBufferExample() 
   Dim f As New PaintBufferForm() 
   f.ShowDialog() 
End Sub 
 
Class PaintBufferForm 
   Inherits Form 
   Private image As RasterImage 
 
   Public Sub New() 
      ' Load the image 
      Dim codecs As New RasterCodecs() 
 
      Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp") 
      image = codecs.Load(srcFileName) 
 
      Text = "PaintBuffer Example" 
   End Sub 
 
   Protected Overrides Sub Dispose(ByVal disposing As Boolean) 
      ' Clean up 
      If disposing Then 
         image.Dispose() 
      End If 
 
      MyBase.Dispose(disposing) 
   End Sub 
 
   Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs) 
      ' Draw the image fit and center on this form 
      Dim destRect As LeadRect = LeadRect.FromLTRB(ClientRectangle.Left, ClientRectangle.Top, ClientRectangle.Right, ClientRectangle.Bottom) 
      destRect = RasterImage.CalculatePaintModeRectangle( 
         image.ImageWidth, 
         image.ImageHeight, 
         destRect, 
         RasterPaintSizeMode.Fit, 
         RasterPaintAlignMode.Center, 
         RasterPaintAlignMode.Center) 
 
      Dim buffer(image.BytesPerLine - 1) As Byte 
 
      image.Access() 
      For row As Integer = 0 To image.Height - 1 
         image.GetRow(row, buffer, 0, image.BytesPerLine) 
         RasterImagePainter.PaintBuffer(image, e.Graphics, LeadRect.Empty, LeadRect.Empty, destRect, LeadRect.Empty, buffer, 0, row, 1, RasterPaintProperties.Default) 
         Thread.Sleep(10) 
      Next 
      image.Release() 
 
      MyBase.OnPaint(e) 
   End Sub 
End Class 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images" 
End Class 

Requirements

Target Platforms

Help Version 19.0.2017.10.18
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Leadtools.Drawing Assembly