GDI+ Image::SetPropertyItem not working as expected - c++

Question

I am trying to use SetPropertyItem to set a Date Taken property to a file (click here for MSDN docs description).
I have tried assigning a newly initialized FILETIME to an input image with no success (or error messages). To ensure that it was not an issue with Date Taken, I also tried following this MSDN example to no avail.
Currently, I am attempting to extract a Date Taken property item from one input file (works fine) and attempting to set it to a different file. This approach does not work either, and the Status code returned is always 0 (Ok).
The code I am using is below. I can only assume I am making a simple mistake or perhaps misunderstanding what SetPropertyItem is supposed to do. I thought that SetPropertyItem changed the metadata value such that it can be viewed through the Windows properties menu, like in this screenshot.
#include <windows.h>
#include <gdiplus.h>
#include <stdio.h>
#include <iostream>
using namespace Gdiplus;
#pragma comment(lib, "gdiplus.lib")
int main()
{
GdiplusStartupInput gdiplusStartupInput;
ULONG_PTR gdiplusToken;
GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
Image* image = new Image(L"FakePhoto.jpg"); // input image
UINT totalBufferSize;
UINT numProperties; // setup the buffer
image->GetPropertySize(&totalBufferSize, &numProperties);
// extract all metadata property items
PropertyItem* pAllItems = (PropertyItem*)malloc(totalBufferSize);
image->GetAllPropertyItems(totalBufferSize, numProperties, pAllItems);
for (UINT j = 0; j < numProperties; ++j)
{ // loop through each property
if (pAllItems[j].id == PropertyTagExifDTOrig)
{ // if it's the Date Taken property
PropertyItem* propItem = new PropertyItem;
Image* newImage = new Image(L"Test2.jpg");
Status status; // second image
propItem->id = PropertyTagExifDTOrig;
propItem->length = pAllItems[j].length;
propItem->type = PropertyTagTypeASCII;
propItem->value = pAllItems[j].value;
// create a new property item with the input photo Date Taken metadata
status = newImage->SetPropertyItem(propItem);
if (status == Ok)
std::cout << "No errors.";
}
}
free(pAllItems);
delete image;
GdiplusShutdown(gdiplusToken);
}
Any help is greatly appreciated. Also, I apologise about any obvious/potential errors. I am still learning the ropes as this is my first time using C++.

Answer 1

You code works fine, but you must save the image back, for example like this
...
newImage->SetPropertyItem(propItem);
CLSID clsid;
GetEncoderClsid(L"image/jpeg", &clsid);
newImage->Save(L"Test2.jpg", &clsid);
...
BOOL GetEncoderClsid(const WCHAR* format, CLSID* pClsid)
{
UINT num = 0;
UINT size = 0;
ImageCodecInfo* info = NULL;
ZeroMemory(pClsid, sizeof(CLSID));
GetImageEncodersSize(&num, &size);
if (size == 0)
return FALSE;
info = (ImageCodecInfo*)(malloc(size));
if (info == NULL)
return FALSE;
GetImageEncoders(num, size, info);
for (UINT j = 0; j < num; ++j)
{
if (!wcscmp(info[j].MimeType, format))
{
*pClsid = info[j].Clsid;
free(info);
return TRUE;
}
}
free(info);
return FALSE;
}