LookupIconIdFromDirectoryEx function (winuser.h)
Searches through icon (RT_GROUP_ICON) or cursor (RT_GROUP_CURSOR) resource data for the icon or cursor that best fits the current display device.
If more than one image exists in resource group, this method uses the following criteria to choose an image:
- The image closest but not exceed the requested size is selected.
- If two or more images of that size are present, the one that matches the color depth of the display is chosen.
- If no images exactly match the color depth of the display, the image with the greatest color depth that does not exceed the color depth of the display is chosen. If all exceed the color depth, the one with the lowest color depth is chosen.
Syntax
int LookupIconIdFromDirectoryEx(
[in] PBYTE presbits,
[in] BOOL fIcon,
[in] int cxDesired,
[in] int cyDesired,
[in] UINT Flags
);
Parameters
[in] presbits
Type: PBYTE
The icon or cursor directory data. Because this function does not validate the resource data, it causes a general protection (GP) fault or returns an undefined value if presbits is not pointing to valid resource data.
[in] fIcon
Type: BOOL
Indicates whether an icon or a cursor is sought. If this parameter is TRUE, the function is searching for an icon; if the parameter is FALSE, the function is searching for a cursor.
[in] cxDesired
Type: int
The desired width, in pixels, of the icon. If this parameter is zero, the function uses the SM_CXICON or SM_CXCURSOR system metric value.
[in] cyDesired
Type: int
The desired height, in pixels, of the icon. If this parameter is zero, the function uses the SM_CYICON or SM_CYCURSOR system metric value.
[in] Flags
Type: UINT
A combination of the following values.
| Value | Meaning |
|---|---|
|
Uses the default color format. |
|
Creates a monochrome icon or cursor. |
Return value
Type: int
If the function succeeds, the return value is an integer resource identifier for the icon (RT_ICON) or cursor (RT_CURSOR) that best fits the current display device.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
Remarks
A resource file of type RT_GROUP_ICON (RT_GROUP_CURSOR indicates cursors) contains icon (or cursor) data in several device-dependent and device-independent formats. LookupIconIdFromDirectoryEx searches the resource file for the icon (or cursor) that best fits the current display device and returns its integer identifier. The FindResource and FindResourceEx functions use the MAKEINTRESOURCE macro with this identifier to locate the resource in the module.
The icon directory is loaded from a resource file with resource type RT_GROUP_ICON (or RT_GROUP_CURSOR for cursors), and an integer resource name for the specific icon (RT_ICON) or cursor (RT_CURSOR) to be loaded. LoadResource and CreateIconFromResourceEx functions may be used to create a corresponding icon or cursor.
The LoadIcon, LoadImage, and LoadCursor functions use this function to search the specified resource data for the icon or cursor that best fits the current display device. LoadIconWithScaleDown uses alternative search criteria for a best fit.
Examples
For an example, see Sharing Icon Resources.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 2000 Professional [desktop apps only] |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Target Platform | Windows |
| Header | winuser.h (include Windows.h) |
| Library | User32.lib |
| DLL | User32.dll |
See also
Conceptual
Reference