CreateBitmap function (wingdi.h)

The CreateBitmap function creates a bitmap with the specified width, height, and color format (color planes and bits-per-pixel).

Syntax

HBITMAP CreateBitmap(
  [in] int        nWidth,
  [in] int        nHeight,
  [in] UINT       nPlanes,
  [in] UINT       nBitCount,
  [in] const VOID *lpBits
);

Parameters

[in] nWidth

The bitmap width, in pixels.

[in] nHeight

The bitmap height, in pixels.

[in] nPlanes

The number of color planes used by the device.

[in] nBitCount

The number of bits required to identify the color of a single pixel.

[in] lpBits

A pointer to an array of color data used to set the colors in a rectangle of pixels. Each scan line in the rectangle must be word aligned (scan lines that are not word aligned must be padded with zeros). The buffer size expected, cj, can be calculated using the formula:

cj = (((nWidth * nPlanes * nBitCount + 15) >> 4) << 1) * nHeight;

If this parameter is NULL, then the contents of the new bitmap are undefined.

Return value

If the function succeeds, the return value is a handle to a bitmap.

If the function fails, the return value is NULL.

This function can return the following value.

Remarks

The CreateBitmap function creates a device-dependent bitmap.

After a bitmap is created, it can be selected into a device context by calling the SelectObject function. However, the bitmap can only be selected into a device context if the bitmap and the DC have the same format.

The CreateBitmap function can be used to create color bitmaps. However, for performance reasons applications should use CreateBitmap to create monochrome bitmaps and CreateCompatibleBitmap to create color bitmaps. Whenever a color bitmap returned from CreateBitmap is selected into a device context, the system checks that the bitmap matches the format of the device context it is being selected into. Because CreateCompatibleBitmap takes a device context, it returns a bitmap that has the same format as the specified device context. Thus, subsequent calls to SelectObject are faster with a color bitmap from CreateCompatibleBitmap than with a color bitmap returned from CreateBitmap.

If the bitmap is monochrome, zeros represent the foreground color and ones represent the background color for the destination device context.

If an application sets the nWidth or nHeight parameters to zero, CreateBitmap returns the handle to a 1-by-1 pixel, monochrome bitmap.

When you no longer need the bitmap, call the DeleteObject function to delete it.

Requirements

See also

Bitmap Functions

Bitmaps Overview

CreateBitmapIndirect

CreateCompatibleBitmap

CreateDIBitmap

DeleteObject

GetBitmapBits

SelectObject

SetBitmapBits