Creating and Displaying a Caret

Upon receiving the keyboard focus, the window should create and display the caret. Use the CreateCaret function to create a caret in the given window. You can then call SetCaretPos to set the current position of the caret and ShowCaret to make the caret visible.

The system sends the WM_SETFOCUS message to the window receiving keyboard focus; therefore, an application should create and display the caret while processing this message.

HWND hwnd, // window handle

int x; // horizontal coordinate of cursor

int y; // vertical coordinate of cursor

int nWidth; // width of cursor

int nHeight; // height of cursor

char *lpszChar; // pointer to character

case WM_SETFOCUS:

// Create a solid black caret.

CreateCaret(hwnd, (HBITMAP) NULL, nWidth, nHeight);

// Adjust the caret position, in client coordinates.

SetCaretPos(x, y);

// Display the caret.

ShowCaret(hwnd);

break;

To create a caret based on a bitmap, you must specify a bitmap handle when using CreateCaret. You can use a graphics application to create the bitmap and a resource compiler to add the bitmap to your application's resources. Your application can then use the LoadBitmap function to load the bitmap handle. For example, you could replace the CreateCaret line in the preceding example with the following lines to create a bitmap caret.

// Load the application-defined caret resource.

hCaret = LoadBitmap(hinst, MAKEINTRESOURCE(120));

// Create a bitmap caret.

CreateCaret(hwnd, hCaret, 0, 0);

Alternatively, you can use the CreateBitmap or CreateDIBitmap function to retrieve the handle of the caret bitmap. For more information about bitmaps, see Bitmaps.

If your application specifies a bitmap handle, CreateCaret ignores the width and height parameters. The bitmap defines the size of the caret.