PA_GetPictureField

version 2003

PA_GetPictureField (tNum; fNum; picture; info) → long

Parameter	Type		Description
tNum	short	→	Table number of the field to access
fNum	short	→	Field number of the field to access
picture	void*	←	Pointer to picture data
info	PA_PictureInfo*	←	Pointer to picture info
Function result	long	←	Picture size in bytes

Description

The routine PA_GetPictureField puts the content of the picture field number fNum of the current record of the table number tNum , in the data pointed to by picture , and returns its size in bytes. In addition, it returns the picture info in info (used when the picture is displayed as a background picture).

If the field is not a picture field, the routine leaves picture and info unchanged, returns 0 and an error code in PA_GetLastError .

If the picture size is unknown, call the function a first time with picture equal to zero. The returned value will be the size of the needed buffer. Allocate the buffer and call the function again with the correct buffer.

4th Dimension uses Macintosh pictures internally. You can get a handle to the picture by calling PA_GetPictureHandleField .

Examples

Get a picture field.

   char            *thePict;
   PA_PictureInfo   theInfo;
   long            pictSize;
 
   // First call the routine with a nil pointer to get the BLOB size
   pictSize = PA_GetPictureField(tNum, fNum, 0, 0 );
   // Then allocate the buffer
   thePict = malloc( pictSize );
   // If it is ok, get a copy of picture data
   if ( thePict )
   {
      pictSize = PA_GetPictureField( tNum, fNum, thePict, &theInfo );
   // Work with it
      /* . . . */
   // Cleanup
      free( thePict );
   }

Error Handling

Use PA_GetLastError to see if an error occurred ( eER_InvalidFileNumber , eER_InvalidFieldNumber ).