A status bar can have many different parts, each displaying a different line of text. You divide a status bar into parts by sending the window an SB_SETPARTS message, which specifies the number of parts to create and the address of an integer array. The array contains one element for each part, and each element specifies the client coordinate of the right edge of a part.
A status bar can have a maximum of 255 parts, although applications typically use far fewer than that. You retrieve a count of the parts in a status bar, as well as the coordinate of the right edge of each part, by sending the window an SB_GETPARTS message.
A simple mode status bar is useful for displaying Help text for menu items while the user is scrolling through the menu. You put a status bar in "simple mode" by sending it an SB_SIMPLE message. A simple mode status bar displays only one part. When the text of the window is set, the window is invalidated, but it is not redrawn until the next WM_PAINT message. Waiting for the message reduces screen flicker by minimizing the number of times the window is redrawn.
The string that a status bar displays while in simple mode is maintained separately from the strings that it displays while it is not in simple mode. This means you can put the window in simple mode, set its text, and switch out of simple mode without the original text being changed.
Windows CE supports a status bar notification, called SBN_SIMPLEMODECHANGE, which a status bar sends when the simple mode changes as a result of receiving an SB_SIMPLE message.