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PaintRegion(Graphics,Rectangle,Rectangle,Rectangle,Rectangle,RasterPaintProperties) Method
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Leadtools Namespace > RasterImage Class > PaintRegion Method : PaintRegion(Graphics,Rectangle,Rectangle,Rectangle,Rectangle,RasterPaintProperties) Method



graphics
The destination Graphics object where the image region will be displayed.
srcRect

A Rectangle 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 Rectangle 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 Rectangle 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 Rectangle object.

destClipRect

A Rectangle 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 Graphics object. You can pass Rectangle.Empty to use the default, which matches the Graphics object. In most cases, however, you should use the rectangle returned by the .NET PaintEventArgs.ClipRectangle or Windows WM_PAINT message.

properties
Options for the display.
Paints the image region to a Graphics object.

Syntax

Visual Basic (Declaration) 
Public Overloads Sub PaintRegion( _
   ByVal graphics As Graphics, _
   ByVal srcRect As Rectangle, _
   ByVal srcClipRect As Rectangle, _
   ByVal destRect As Rectangle, _
   ByVal destClipRect As Rectangle, _
   ByVal properties As RasterPaintProperties _
)
Visual Basic (Usage)Copy Code
Dim instance As RasterImage
Dim graphics As Graphics
Dim srcRect As Rectangle
Dim srcClipRect As Rectangle
Dim destRect As Rectangle
Dim destClipRect As Rectangle
Dim properties As RasterPaintProperties
 
instance.PaintRegion(graphics, srcRect, srcClipRect, destRect, destClipRect, properties)
C# 
public void PaintRegion( 
   Graphics graphics,
   Rectangle srcRect,
   Rectangle srcClipRect,
   Rectangle destRect,
   Rectangle destClipRect,
   RasterPaintProperties properties
)
C++/CLI 
public:
void PaintRegion( 
   Graphics graphics,
   Rectangle srcRect,
   Rectangle srcClipRect,
   Rectangle destRect,
   Rectangle destClipRect,
   RasterPaintProperties properties
)

Parameters

graphics
The destination Graphics object where the image region will be displayed.
srcRect

A Rectangle 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 Rectangle 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 Rectangle 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 Rectangle object.

destClipRect

A Rectangle 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 Graphics object. You can pass Rectangle.Empty to use the default, which matches the Graphics object. In most cases, however, you should use the rectangle returned by the .NET PaintEventArgs.ClipRectangle or Windows WM_PAINT message.

properties
Options for the display.

Example

Visual BasicCopy Code
Public Sub PaintRegionExample()
   Dim f As PaintRegionForm = New PaintRegionForm()
   f.ShowDialog()
End Sub

Private Class PaintRegionForm : Inherits Form
   Private image As RasterImage

   Public Sub New()
      ' Load the image
      RasterCodecs.Startup()
      Dim codecs As RasterCodecs = New RasterCodecs()

      Dim srcFileName As String = LeadtoolsExamples.Common.ImagesPath.Path + "Image1.cmp"
      image = codecs.Load(srcFileName)

      ' add a region to the image
      image.AddEllipseToRegion(RasterRegionXForm.Default, New Rectangle(image.Width \ 4, image.Height \ 4, image.Width \ 2, image.Height \ 2), RasterRegionCombineMode.Set)

      Text = "PaintRegion Example"
   End Sub

   Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
      ' Clean up
      If disposing Then
         image.Dispose()
         RasterCodecs.Shutdown()
      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 Rectangle = RasterImage.CalculatePaintModeRectangle(image.ImageWidth, image.ImageHeight, ClientRectangle, RasterPaintSizeMode.Fit, RasterPaintAlignMode.Center, RasterPaintAlignMode.Center)

      image.PaintRegion(e.Graphics, Rectangle.Empty, Rectangle.Empty, destRect, Rectangle.Empty, RasterPaintProperties.Default)

      MyBase.OnPaint(e)
   End Sub
End Class
C#Copy Code
public void PaintRegionExample() 
{ 
   PaintRegionForm f = new PaintRegionForm(); 
   f.ShowDialog(); 
} 
 
class PaintRegionForm : Form 
{ 
   RasterImage image; 
 
   public PaintRegionForm() 
   { 
      // Load the image 
      RasterCodecs.Startup(); 
      RasterCodecs codecs = new RasterCodecs(); 
 
      string srcFileName = LeadtoolsExamples.Common.ImagesPath.Path + "Image1.cmp"; 
      image = codecs.Load(srcFileName); 
 
      // add a region to the image 
      image.AddEllipseToRegion(RasterRegionXForm.Default, new Rectangle(image.Width / 4, image.Height / 4, image.Width / 2, image.Height / 2), RasterRegionCombineMode.Set); 
 
      Text = "PaintRegion Example"; 
   } 
 
   protected override void Dispose(bool disposing) 
   { 
      // Clean up 
      if(disposing) 
      { 
         image.Dispose(); 
         RasterCodecs.Shutdown(); 
      } 
 
      base.Dispose(disposing); 
   } 
 
   protected override void OnPaint(PaintEventArgs e) 
   { 
      // Draw the image fit and center on this form 
      Rectangle destRect = RasterImage.CalculatePaintModeRectangle( 
         image.ImageWidth, 
         image.ImageHeight, 
         ClientRectangle, 
         RasterPaintSizeMode.Fit, 
         RasterPaintAlignMode.Center, 
         RasterPaintAlignMode.Center); 
 
      image.PaintRegion(e.Graphics, Rectangle.Empty, Rectangle.Empty, destRect, Rectangle.Empty, RasterPaintProperties.Default); 
 
      base.OnPaint(e); 
   } 
}

Remarks

This method works the same as Paint, except that only the image region is painted.

Requirements

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

See Also