internal static void SetIconIndex(ShellItem item, int index, bool SelectedIcon)
{
bool HasOverlay = false; //true if it's an overlay
int rVal = 0; //The returned Index
ShellAPI.SHGFI dwflag = ShellAPI.SHGFI.SYSICONINDEX | ShellAPI.SHGFI.PIDL | ShellAPI.SHGFI.ICON;
ShellAPI.FILE_ATTRIBUTE dwAttr = 0;
//build Key into HashTable for this Item
int Key = index * 256;
if (item.IsLink)
{
Key = Key | 1;
dwflag = dwflag | ShellAPI.SHGFI.LINKOVERLAY;
HasOverlay = true;
}
if (item.IsShared)
{
Key = Key | 2;
dwflag = dwflag | ShellAPI.SHGFI.ADDOVERLAYS;
HasOverlay = true;
}
if (SelectedIcon)
{
Key = Key | 4;
dwflag = dwflag | ShellAPI.SHGFI.OPENICON;
HasOverlay = true; //not really an overlay, but handled the same
}
if (imageTable.ContainsKey(Key))
{
rVal = (int)imageTable[Key];
}
else if (!HasOverlay && !item.IsHidden) //for non-overlay icons, we already have
{
rVal = (int)System.Math.Floor((double)Key / 256); // the right index -- put in table
imageTable[Key] = rVal;
}
else //don't have iconindex for an overlay, get it.
{
if (item.IsFileSystem & !item.IsDisk & !item.IsFolder)
{
dwflag = dwflag | ShellAPI.SHGFI.USEFILEATTRIBUTES;
dwAttr = dwAttr | ShellAPI.FILE_ATTRIBUTE.NORMAL;
}
PIDL pidlFull = item.PIDLFull;
ShellAPI.SHFILEINFO shfiSmall = new ShellAPI.SHFILEINFO();
ShellAPI.SHGetFileInfo(pidlFull.Ptr, dwAttr, ref shfiSmall, ShellAPI.cbFileInfo, dwflag | ShellAPI.SHGFI.SMALLICON);
ShellAPI.SHFILEINFO shfiLarge = new ShellAPI.SHFILEINFO();
ShellAPI.SHGetFileInfo(pidlFull.Ptr, dwAttr, ref shfiLarge, ShellAPI.cbFileInfo, dwflag | ShellAPI.SHGFI.LARGEICON);
Marshal.FreeCoTaskMem(pidlFull.Ptr);
lock (imageTable)
{
rVal = ShellAPI.ImageList_ReplaceIcon(smallImageListHandle, -1, shfiSmall.hIcon);
ShellAPI.ImageList_ReplaceIcon(largeImageListHandle, -1, shfiLarge.hIcon);
}
ShellAPI.DestroyIcon(shfiSmall.hIcon);
ShellAPI.DestroyIcon(shfiLarge.hIcon);
imageTable[Key] = rVal;
}
if (SelectedIcon)
{
item.SelectedImageIndex = rVal;
}
else
{
item.ImageIndex = rVal;
}
}