Metafile::EmfToWmfBits method (gdiplusheaders.h)

Article
10/13/2021

Converts an enhanced-format metafile to a Windows Metafile Format (WMF) metafile and stores the converted records in a specified buffer.

Syntax

UINT EmfToWmfBits(
  [in]           HENHMETAFILE hemf,
  [in]           UINT         cbData16,
  [out]          LPBYTE       pData16,
  [in, optional] INT          iMapMode,
  [in, optional] INT          eFlags
);

Parameters

[in] hemf

Type: HENHMETAFILE

Handle to the enhanced-format metafile that is to be converted.

[in] cbData16

Type: UINT

Unsigned integer that specifies the number of bytes in the buffer pointed to by the pData16 parameter.

[out] pData16

Type: LPBYTE

Pointer to a buffer that receives the converted records. If pData16 is NULL, Metafile::EmfToWmfBits returns the number of bytes required to store the converted metafile records.

[in, optional] iMapMode

Type: INT

Optional. Specifies the mapping mode to use in the converted metafile. For a list of possible mapping modes, see SetMapMode. The default value is MM_ANISOTROPIC.

[in, optional] eFlags

Type: EmfToWmfBitsFlags

Optional. Element of the EmfToWmfBitsFlags enumeration that specifies options for the conversion. The default value is EmfToWmfBitsFlagsDefault.

Return value

Type: UINT

If the method succeeds and the buffer pointer is NULL, the return value is the number of bytes required to store the converted records. If the method succeeds and the buffer pointer is a valid pointer, the return value is the size of the metafile data in bytes. If the method fails, the return value is zero.

Remarks

When you call Metafile::EmfToWmfBits to determine the size of the required buffer, you must pass the same value for eFlags that you pass later when you call Metafile::EmfToWmfBits to perform the conversion. Otherwise, the size returned by the first call to Metafile::EmfToWmfBits will be incorrect.

This method cannot convert metafiles of type EmfTypeEmfPlusOnly. If you use this method to convert a metafile of type EmfTypeEmfPlusDual, the Enhanced Metafile (EMF) records in that metafile are converted, but the EMF+ records are not converted.

This method converts an enhanced metafile into a WMF metafile so that its picture can be displayed in an application that recognizes the older format.

The Metafile::EmfToWmfBits method does not invalidate the enhanced metafile handle. Call the DeleteEnhMetaFile function to release the handle when it is no longer needed.

To create a scalable WMF metafile, specify MM_ANISOTROPIC as the iMapMode parameter.

Examples

The following example converts an enhanced-format metafile to a WMF metafile. The last parameter passed to Metafile::EmfToWmfBits specifies that the enhanced-format metafile is embedded as a comment in the converted metafile.

// Construct a Metafile object from an existing EMF disk file.
Metafile myMetafile(L"SourceMetafile.emf");

// Get a handle to the EMF metafile.
HENHMETAFILE hEmf = myMetafile.GetHENHMETAFILE();

// Determine the size of the buffer that will receive the converted records.
UINT size = Metafile::EmfToWmfBits(
   hEmf, 
   0, 
   NULL,
   MM_ANISOTROPIC,
   EmfToWmfBitsFlagsEmbedEmf);

// Allocate a buffer to receive the converted records.
BYTE* buffer = new BYTE[size];

// Convert the EMF records to WMF records.
INT convertedSize = Metafile::EmfToWmfBits(
   hEmf, 
   size,
   buffer, 
   MM_ANISOTROPIC,
   EmfToWmfBitsFlagsEmbedEmf);

// Get a handle to the converted metafile.
HMETAFILE hmf = SetMetaFileBitsEx(size, buffer);

// Write the WMF metafile to a disk file.
CopyMetaFile(hmf, TEXT("ConvertedMetafile.wmf"));

DeleteMetaFile(hmf);
DeleteEnhMetaFile(hEmf);
delete[] buffer;

Requirements

Requirement	Value
Minimum supported client	Windows XP, Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	gdiplusheaders.h (include Gdiplus.h)
Library	Gdiplus.lib
DLL	Gdiplus.dll