Image::GetPropertyIdList method (gdiplusheaders.h)

The Image::GetPropertyIdList method gets a list of the property identifiers used in the metadata of this Image object.

Syntax

Status GetPropertyIdList(
  [in]  UINT   numOfProperty,
  [out] PROPID *list
);

Parameters

[in] numOfProperty

Type: UINT

Integer that specifies the number of elements in the list array. Call the Image::GetPropertyCount method to determine this number.

[out] list

Type: PROPID*

Pointer to an array that receives the property identifiers.

Return value

Type: Status

If the method succeeds, it returns Ok, which is an element of the Status enumeration.

If the method fails, it returns one of the other elements of the Status enumeration.

Remarks

The Image::GetPropertyIdList method returns an array of PROPIDs. Before you call Image::GetPropertyIdList, you must allocate a buffer large enough to receive that array. You can call the Image::GetPropertyCount method of an Image object to determine the size of the required buffer. The size of the buffer should be the return value of Image::GetPropertyCount multiplied by sizeof( PROPID).

Examples

The following example creates an Image object based on a JPEG file. The code calls the Image::GetPropertyIdList method of that Image object to find out what types of metadata are stored in the image.

#include <windows.h>
#include <gdiplus.h>
#include <stdio.h>
using namespace Gdiplus;

INT main()
{
   GdiplusStartupInput gdiplusStartupInput;
   ULONG_PTR gdiplusToken;
   GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);

   UINT count = 0; 
   Image* image = new Image(L"FakePhoto.jpg");

   // How many types of metadata are in the image?
   count = image->GetPropertyCount();
   if(count == 0)
      return 0;

   // Allocate a buffer to receive an array of PROPIDs.
   PROPID* propIDs = new PROPID[count];

   image->GetPropertyIdList(count, propIDs);

   // List the retrieved IDs.
   for(UINT j = 0; j < count; ++j)
      printf("%x\n", propIDs[j]);

   delete [] propIDs;
   delete image;   
  
   GdiplusShutdown(gdiplusToken);
   return 0;
}

The preceding code, along with a particular file, FakePhoto.jpg, produced the following output:

320
10f
110
9003
829a
5090
5091

The preceding output shows the hexadecimal value of each property identifier. You can look up those numbers in Gdiplusimaging.h and find out that they represent the following property tags.

Requirements

See also

Image

Image::GetAllPropertyItems

Image::GetPropertyCount

Image::GetPropertyItem

Image::GetPropertyItemSize

Image::GetPropertySize

Image::RemovePropertyItem

Image::SetPropertyItem

PropertyItem

Reading and Writing Metadata