unsafe HRESULT SaveHdropToHandle(ref IntPtr handle, string[] files)
{
int size = sizeof(Shell32.DROPFILES);
foreach (var f in files)
{
size += (f.Length + 1) * 2;
}
size += 2; // Terminal null
var hg = Kernel32.GlobalReAlloc(handle, size, Kernel32.GMEM.GMEM_MOVEABLE);
if (hg.IsNull)
{
return(HRESULT.E_OUTOFMEMORY);
}
var lc = Kernel32.GlobalLock(hg);
Shell32.DROPFILES *df = (Shell32.DROPFILES *)lc.ToPointer();
df->pFiles = (uint)files.Length;
df->fNC = false;
df->fWide = false;
char *ptr = ((char *)df) + sizeof(Shell32.DROPFILES);
foreach (var f in files)
{
fixed(char *str = f)
{
Buffer.MemoryCopy(str, ptr, f.Length + 2, f.Length + 2);
ptr[f.Length] = '\0';
ptr += f.Length + 1;
}
*ptr = '\0';
}
Kernel32.GlobalUnlock(hg);
return(HRESULT.S_OK);
}
private unsafe HRESULT SaveFileListToHandle(IntPtr handle, string[] files)
{
if (files is null || files.Length == 0)
{
return(HRESULT.S_OK);
}
if (handle == IntPtr.Zero)
{
return(HRESULT.E_INVALIDARG);
}
// CF_HDROP consists of a DROPFILES struct followed by an list of strings
// including the terminating null character. An additional null character
// is appended to the final string to terminate the array.
// E.g. if the files c:\temp1.txt and c:\temp2.txt are being transferred,
// the character array is: "c:\temp1.txt\0c:\temp2.txt\0\0"
// Determine the size of the data structure.
uint sizeInBytes = (uint)sizeof(Shell32.DROPFILES);
for (int i = 0; i < files.Length; i++)
{
sizeInBytes += ((uint)files[i].Length + 1) * 2;
}
sizeInBytes += 2;
// Allocate the Win32 memory
IntPtr newHandle = Kernel32.GlobalReAlloc(
handle,
sizeInBytes,
Kernel32.GMEM.MOVEABLE | Kernel32.GMEM.DDESHARE);
if (newHandle == IntPtr.Zero)
{
return(HRESULT.E_OUTOFMEMORY);
}
IntPtr basePtr = Kernel32.GlobalLock(newHandle);
if (basePtr == IntPtr.Zero)
{
return(HRESULT.E_OUTOFMEMORY);
}
// Write out the DROPFILES struct.
Shell32.DROPFILES *pDropFiles = (Shell32.DROPFILES *)basePtr;
pDropFiles->pFiles = (uint)sizeof(Shell32.DROPFILES);
pDropFiles->pt = Point.Empty;
pDropFiles->fNC = BOOL.FALSE;
pDropFiles->fWide = BOOL.TRUE;
char *dataPtr = (char *)(basePtr + (int)pDropFiles->pFiles);
// Write out the strings.
for (int i = 0; i < files.Length; i++)
{
int bytesToCopy = files[i].Length * 2;
fixed(char *pFile = files[i])
{
Buffer.MemoryCopy(pFile, dataPtr, bytesToCopy, bytesToCopy);
}
dataPtr = (char *)((IntPtr)dataPtr + bytesToCopy);
*dataPtr = '\0';
dataPtr++;
}
*dataPtr = '\0';
dataPtr++;
Kernel32.GlobalUnlock(newHandle);
return(HRESULT.S_OK);
}