Visual C++ and MFC Programming 2nd Edition

Visual C++ and MFC Fundamentals Chapter 20: List-Based Controls

of images that the image list will contain. The nGrow argument represents the number of

images by which the image list can grow.

If you had designed an unmasked bitmap using the image editor and you want to

initialize it, call the second or the third versions of the Create() method. The nBitmapID

argument is the identifier of the bitmap. If you want to provide the string that contains the

identifiers of the images, pass it as the lpszBitmapID argument. The cx value represents

the width of each picture. The crMask is the color used to mask the transparency of the

picture. Each pixel of the picture that matches this color will turn to black. Here is an

example of using this Create() method:

BOOL CAnimation1Dlg::OnInitDialog()

{

CDialog::OnInitDialog();

SetIcon(m_hIcon, TRUE); // Set big icon

SetIcon(m_hIcon, FALSE); // Set small icon

// TODO: Add extra initialization here

CImageList ImgList;

ImgList.Create(IDB_IMGLIST, 48, 4, RGB(255, 55, 5));

return TRUE; // return TRUE unless you set the focus to a control

}

Besides, or instead of using, the Create() method, you can call CImageList::Add() to

add a bitmap to the CImageList variable. Its syntaxes are:

int Add(CBitmap* pbmImage, CBitmap* pbmMask);

int Add(CBitmap* pbmImage, COLORREF crMask);

int Add(HICON hIcon );

The pbmImage argument represents the bitmap to be added, unless you want to add an

icon, in which case you would use the third version. The pbmMask argument is the

bitmap that will be used to mask the image list. You can use a color instead, in which

case you would pass a COLORREF value as the second argument to the second version.

If you want to remove a picture from the image list, call the CImageList::Remove()

method. Its syntax:

BOOL Remove(int nImage);

The nImage argument is the index of the picture to be removed. Instead of removing a

picture, you can just replace it with another picture. This is done using the

CImageList::Replace() method whose syntaxes are:

BOOL Replace(int nImage, CBitmap* pbmImage, CBitmap* pbmMask);

int Replace(int nImage, HICON hIcon);

Once an image list is ready, you can use it directly in an application or make it available

to a control that can use it. One way you can use an image list is to display one or more of

its pictures on a dialog box, a form, or a view. To do this, you would call the

CImageList::Draw() method. Its syntax is:

BOOL Draw(CDC* pdc, int nImage, POINT pt, UINT nStyle);