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FromEmf Method
See Also  Example
Leadtools Namespace > RasterImage Class : FromEmf Method



hemf
Handle to the EMF to be converted.
width
Amount by which to scale the enhanced metafiles original width.
height
Amount by which to scale the enhanced metafiles original height.
Converts an enhanced Windows metafile (EMF) into a LEAD RasterImage object.

Syntax

Visual Basic (Declaration)  
Public Shared Function FromEmf( _
   ByVal hemf As IntPtr, _
   ByVal width As Integer, _
   ByVal height As Integer _
) As RasterImage
Visual Basic (Usage) Copy Code
Dim hemf As IntPtr
Dim width As Integer
Dim height As Integer
Dim value As RasterImage
 
value = RasterImage.FromEmf(hemf, width, height)
C#  
public static RasterImage FromEmf( 
   IntPtr hemf,
   int width,
   int height
)
C++/CLI  
public:
static RasterImage^ FromEmf( 
   IntPtr hemf,
   int width,
   int height
) 

Parameters

hemf
Handle to the EMF to be converted.
width
Amount by which to scale the enhanced metafiles original width.
height
Amount by which to scale the enhanced metafiles original height.

Return Value

The newly created RasterImage object.

Example

This example loads a RasterImage, converts it to a EMF, then converts the EMF back to a RasterImage.

Visual Basic Copy Code
<DllImport("Gdi32", CharSet:=CharSet.Auto)> _
Shared Function DeleteEnhMetaFile(ByVal hemf As IntPtr) As Integer
End Function

Public Sub FromEmfExample()
   RasterCodecs.Startup()
   Dim codecs As New RasterCodecs()

   ' Load an image
   Dim image As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "Image1.cmp", 24, CodecsLoadByteOrder.BgrOrGray, 1, 1)

   ' Convert it to EMF
   Dim hemf As IntPtr = image.ToEmf()

   ' Note, since we converted to an EMF we have two copies of the image in memory and "image" is still usable
   image.Dispose()

   ' Convert the EMF back to a RasterImage preserving the size
   image = RasterImage.FromEmf(hemf, 0, 0)

   ' Not since we converted from the EMF, we need to delete it ourselves
   DeleteEnhMetaFile(hemf)

   ' Save it to disk
   codecs.Save(image, LeadtoolsExamples.Common.ImagesPath.Path + "Image1_FromEmf.bmp", RasterImageFormat.Bmp, 24)

   image.Dispose()

   ' Clean up
   codecs.Dispose()
   RasterCodecs.Shutdown()
End Sub
C# Copy Code
      [DllImport("Gdi32", CharSet = CharSet.Auto)] 
static extern int DeleteEnhMetaFile(IntPtr hemf); 
 
public void FromEmfExample() 

   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // Load an image 
   RasterImage image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "Image1.cmp", 24, CodecsLoadByteOrder.BgrOrGray, 1, 1); 
 
   // Convert it to EMF 
   IntPtr hemf = image.ToEmf(); 
 
   // Note, since we converted to an EMF we have two copies of the image in memory and "image" is still usable 
   image.Dispose(); 
 
   // Convert the EMF back to a RasterImage preserving the size 
   image = RasterImage.FromEmf(hemf, 0, 0); 
 
   // Not since we converted from the EMF, we need to delete it ourselves 
   DeleteEnhMetaFile(hemf); 
 
   // Save it to disk 
   codecs.Save(image, LeadtoolsExamples.Common.ImagesPath.Path + "Image1_FromEmf.bmp", RasterImageFormat.Bmp, 24); 
 
   image.Dispose(); 
 
   // Clean up 
   codecs.Dispose(); 
   RasterCodecs.Shutdown(); 
}

Remarks

When this method is completed, there are two copies of the drawing in memory: the new RasterImage object and the original EMF. Freeing one will not affect the other.

The enhanced metafile can be loaded at the original dimension or scaled by using the width and height parameters.

If width == 0 and height == 0 - the enhanced metafile is loaded at the size present in the file.

If width == 0 and height > 0 - the enhanced metafile is stretched so that it has the height height (preserving the aspect ratio).

If width > 0 and height == 0 - the enhanced metafile is stretched so that it has the width width (preserving the aspect ratio).

If width > 0 and height > 0 - the enhanced metafile is stretched so that it has the width width and height height (the aspect ratio is ignored).

This function does not support signed images.

Requirements

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

See Also