MFC - Image Lists

An Image List is a collection of same-sized images, each of which can be referred to by its zero-based index. Image lists are used to efficiently manage large sets of icons or bitmaps. Image lists are represented by CImageList class.

Here is the list of methods in CImageList class.

Sr.No.	Name & Description
1	Add Adds an image or images to an image list.
2	Attach Attaches an image list to a CImageList object.
3	BeginDrag Begins dragging an image.
4	Copy Copies an image within a CImageList object.
5	Create Initializes an image list and attaches it to a CImageList object.
6	DeleteImageList Deletes an image list.
7	DeleteTempMap Called by the CWinApp idle-time handler to delete any temporaryCImageList object created by FromHandle.
8	Detach Detaches an image list object from a CImageList object and returns a handle to an image list.
9	DragEnter Locks updates during a drag operation and displays the drag image at a specified position.
10	DragLeave Unlocks the window and hides the drag image so that the window can be updated.
11	DragMove Moves the image that is being dragged during a drag-and-drop operation.
12	DragShowNolock Shows or hides the drag image during a drag operation, without locking the window.
13	Draw Draws the image that is being dragged during a drag-and-drop operation.
14	DrawEx Draws an image list item in the specified device context. The function uses the specified drawing style and blends the image with the specified color.
15	DrawIndirect Draws an image from an image list.
16	EndDrag Ends a drag operation.
17	ExtractIcon Creates an icon based on an image and mask in an image list.
18	FromHandle Returns a pointer to a CImageList object when given a handle to an image list. If a CImageList object is not attached to the handle, a temporary CImageList object is created and attached.
19	FromHandlePermanent Returns a pointer to a CImageList object when given a handle to an image list. If a CImageList object is not attached to the handle, NULL is returned.
20	GetBkColor Retrieves the current background color for an image list.
21	GetDragImage Gets the temporary image list that is used for dragging.
22	GetImageCount Retrieves the number of images in an image list.
23	GetImageInfo Retrieves information about an image.
24	GetSafeHandle Retrieves m_hImageList.
25	Read Reads an image list from an archive.
26	Remove Removes an image from an image list.
27	Replace Replaces an image in an image list with a new image.
28	SetBkColor Sets the background color for an image list.
29	SetDragCursorImage Creates a new drag image.
30	SetImageCount Resets the count of images in an image list.
32	SetOverlayImage Adds the zero-based index of an image to the list of images to be used as overlay masks.
33	Write Writes an image list to an archive.

Let us create a new MFC Application MFCImageListDemo with the following settings.

Step 1 − Add bmp file as a resource in your application.

Step 2 − In header file of CMFCImageListDemoView class, add the following two variables.

CImageList ImageList;
int nImage;

Step 3 − Add the following code in constructor of CMFCImageListDemoView.

CMFCImageListDemoView::CMFCImageListDemoView() {
   // TODO: add construction code here
   ImageList.Create(800, 800, ILC_COLOR, 4, 1);
   
   CBitmap bmp;
   bmp.LoadBitmap(IDB_BITMAP1);
   ImageList.Add(&bmp, RGB(0, 0, 0));

}

Step 4 − Call the CImageList::Draw() method as follows.

void CMFCImageListDemoView::OnDraw(CDC* pDC) {
   CMFCImageListDemoDoc* pDoc = GetDocument();
   ASSERT_VALID(pDoc);

   nImage = 0;
   ImageList.Draw(pDC , nImage, CPoint(0,0), ILD_NORMAL);
   Invalidate();

   if (!pDoc)
      return;

   // TODO: add draw code for native data here
}

Step 5 − When you run this application, you will see the following output.

mfc_windows_controls.htm