How do i extract dragged & dropped filenames from a DROPFILES struct - c++

Question

I have a window with no controls with WS_EX_ACCEPTFILES enabled and the event triggers successfully when dragging files from explorer. What I need to do is extract the files to a vector. From what I've read, the wParam is supposed to contain the location of the files within a DROPFILES struct but I don't know how to access them.
LRESULT CALLBACK StaticWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR
uIdSubclass, DWORD_PTR dwRefData)
{
if (uMsg == WM_DROPFILES)
{
// extract files here
vector<string> files;
}
return DefSubclassProc(hwnd, uMsg, wParam, lParam);
}
I don't need to send them to any controls since my window is for an openGL application, I just need to retain them in a list, how can it be done?

Answer 1

Per the WM_DROPFILES documentation:
Parameters
hDrop
A handle to an internal structure describing the dropped files. Pass this handle to DragFinish, DragQueryFile, or DragQueryPoint() to retrieve information about the dropped files.
lParam
Must be zero.
Simply type-cast the wParam to HDROP and call the drag-drop functions as needed, eg:
LRESULT CALLBACK StaticWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
if (uMsg == WM_DROPFILES)
{
HDROP hDrop = reinterpret_cast<HDROP>(wParam);
// extract files here
vector<string> files;
char filename[MAX_PATH];
UINT count = DragQueryFileA(hDrop, -1, NULL, 0);
for(UINT i = 0; i < count; ++i)
{
if (DragQueryFileA(hDrop, i, filename, MAX_PATH))
files.push_back(filename);
}
DragFinish(hDrop);
return 0;
}
return DefSubclassProc(hwnd, uMsg, wParam, lParam);
}
Alternatively:
LRESULT CALLBACK StaticWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
if (uMsg == WM_DROPFILES)
{
HDROP hDrop = reinterpret_cast<HDROP>(wParam);
// extract files here
vector<string> files;
string filename;
UINT count = DragQueryFileA(hDrop, -1, NULL, 0);
for(UINT i = 0; i < count; ++i)
{
UINT size = DragQueryFileA(hDrop, i, NULL, 0);
if (size > 0)
{
filename.resize(size);
DragQueryFileA(hDrop, i, &filename[0], size+1);
files.push_back(filename);
}
}
DragFinish(hDrop);
return 0;
}
return DefSubclassProc(hwnd, uMsg, wParam, lParam);
}