/// <summary>
/// Gets an icons reource id if available in the format:
/// "filename, index"
/// where the first part is a string and the 2nd part is a negativ integer number).
///
/// This format is usally used by the Windows Shell libraries so we use it here
/// to add missing ResourceIds.
/// </summary>
/// <param name="parentIdList"></param>
/// <param name="filename"></param>
/// <param name="index"></param>
/// <returns></returns>
internal static bool GetIconResourceId(IdList parentIdList,
out string filename,
out int index)
{
filename = null;
index = -1;
IntPtr parentPtr = default(IntPtr);
IntPtr relChildPtr = default(IntPtr);
IntPtr ptrShellFolder = default(IntPtr);
IntPtr ptrExtractIcon = default(IntPtr);
IntPtr smallHicon = default(IntPtr);
IntPtr largeHicon = default(IntPtr);
try
{
if (parentIdList.Size == 0)
{
parentPtr = PidlManager.IdListToPidl(parentIdList);
relChildPtr = PidlManager.IdListToPidl(IdList.Create());
}
else
{
IdList parIdList = null, relChildIdList = null;
PidlManager.GetParentChildIdList(parentIdList, out parIdList, out relChildIdList);
parentPtr = PidlManager.IdListToPidl(parIdList);
relChildPtr = PidlManager.IdListToPidl(relChildIdList);
}
if (parentPtr == default(IntPtr) || relChildPtr == default(IntPtr))
{
return(false);
}
Guid guid = typeof(IShellFolder2).GUID;
HRESULT hr = NativeMethods.SHBindToParent(parentPtr, guid,
out ptrShellFolder, ref relChildPtr);
if (hr != HRESULT.S_OK)
{
return(false);
}
using (var shellFolder = new ShellFolder(ptrShellFolder))
{
if (shellFolder == null)
{
return(false);
}
guid = typeof(IExtractIcon).GUID;
var pidls = new IntPtr[] { relChildPtr };
hr = shellFolder.Obj.GetUIObjectOf(IntPtr.Zero, 1, pidls, guid,
IntPtr.Zero, out ptrExtractIcon);
if (hr != HRESULT.S_OK)
{
return(false);
}
using (var extractIcon = new GenericCOMFolder <IExtractIcon>(ptrExtractIcon))
{
if (extractIcon == null)
{
return(false);
}
var iconFile = new StringBuilder(NativeMethods.MAX_PATH);
uint pwFlags = 0;
hr = extractIcon.Obj.GetIconLocation(0, iconFile,
(uint)iconFile.Capacity,
ref index, ref pwFlags);
if (hr != HRESULT.S_OK)
{
return(false);
}
if (string.IsNullOrEmpty(iconFile.ToString()))
{
return(false);
}
filename = iconFile.ToString();
return(true);
}
}
}
finally
{
if (parentPtr != default(IntPtr))
{
NativeMethods.ILFree(parentPtr);
}
////if (relChildPtr != default(IntPtr))
//// Shell32.ILFree(relChildPtr);
if (smallHicon != default(IntPtr))
{
NativeMethods.DestroyIcon(smallHicon);
}
if (largeHicon != default(IntPtr))
{
NativeMethods.DestroyIcon(largeHicon);
}
}
}