LEADTOOLS GDI/GDI+ (Leadtools.Drawing assembly)
LEAD Technologies, Inc

FromWmf(IntPtr,Int32,Int32) Method

Example 





Handle to the WMF to be converted.
Amount by which to scale the metafile's original width.
Amount by which to scale the metafile's original height.
Converts a Windows Metafile (WMF) into a LEADTOOLS Leadtools.RasterImage object.
Syntax
public static RasterImage FromWmf( 
   IntPtr hwmf,
   int width,
   int height
)
'Declaration
 
Public Overloads Shared Function FromWmf( _
   ByVal hwmf As IntPtr, _
   ByVal width As Integer, _
   ByVal height As Integer _
) As RasterImage
'Usage
 
Dim hwmf As IntPtr
Dim width As Integer
Dim height As Integer
Dim value As RasterImage
 
value = RasterImageConverter.FromWmf(hwmf, width, height)
public static RasterImage FromWmf( 
   IntPtr hwmf,
   int width,
   int height
)
 function Leadtools.Drawing.RasterImageConverter.FromWmf(IntPtr,Int32,Int32)( 
   hwmf ,
   width ,
   height 
)
public:
static RasterImage^ FromWmf( 
   IntPtr hwmf,
   int width,
   int height
) 

Parameters

hwmf
Handle to the WMF to be converted.
width
Amount by which to scale the metafile's original width.
height
Amount by which to scale the metafile's original height.

Return Value

The newly created Leadtools.RasterImage object.
Remarks

Some metafiles do not have a background color, and hence, when the metafile is used to create a Leadtools.RasterImage object, the area not covered by the metafile objects will contain the default image background color (black). To create a raster image from a metafile like this with a specific background color, use FromWmf(hemf, width, height, backColor).

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

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

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

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

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

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

This method does not support signed images.

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

Example
 
<DllImport("Gdi32", CharSet:=CharSet.Auto)> _
   Private Shared Function DeleteMetaFile(ByVal hwmf As IntPtr) As Integer
   End Function

   Public Sub FromWmfExample()
      Dim codecs As New RasterCodecs()

      Dim hwmf As IntPtr

      ' Load an image
      Using image As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"), 24, CodecsLoadByteOrder.BgrOrGray, 1, 1)
         ' Convert it to WMF
         hwmf = RasterImageConverter.ToWmf(image)

         ' Note, since we converted to an WMF we have two copies of the image in memory and "image" is still usable
      End Using

      ' Convert the WMF back to a RasterImage preserving the size
      Using image As RasterImage = RasterImageConverter.FromWmf(hwmf, 0, 0)
         ' Not since we converted from the WMF, we need to delete it ourselves
         DeleteMetaFile(hwmf)

         ' Save it to disk
         codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "Image1_FromWmf.bmp"), RasterImageFormat.Bmp, 24)
      End Using

      ' Clean up
      codecs.Dispose()
   End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class
[DllImport("Gdi32", CharSet = CharSet.Auto)]
   private static extern int DeleteMetaFile(IntPtr hwmf);

   public void FromWmfExample()
   {
      RasterCodecs codecs = new RasterCodecs();

      IntPtr hwmf;

      // Load an image
      using(RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"), 24, CodecsLoadByteOrder.BgrOrGray, 1, 1))
      {
         // Convert it to WMF
         hwmf = RasterImageConverter.ToWmf(image);

         // Note, since we converted to an WMF we have two copies of the image in memory and "image" is still usable
      }

      // Convert the WMF back to a RasterImage preserving the size
      using(RasterImage image = RasterImageConverter.FromWmf(hwmf, 0, 0))
      {
         // Not since we converted from the WMF, we need to delete it ourselves
         DeleteMetaFile(hwmf);

         // Save it to disk
         codecs.Save(image, Path.Combine(LEAD_VARS.ImagesDir, "Image1_FromWmf.bmp"), RasterImageFormat.Bmp, 24);

      }

      // Clean up
      codecs.Dispose();
   }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}
Requirements

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

See Also

Reference

RasterImageConverter Class
RasterImageConverter Members
Overload List
FromWmf(hemf, width, height, backColor)
ChangeFromEmf(IntPtr,Int32,Int32) Method
ChangeFromWmf(IntPtr,Int32,Int32) Method
FromEmf
ChangeToEmf Method
ChangeToWmf Method
ToEmf
ToWmf

 

 


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