Win32 UI Control API Reference
This section provides comprehensive documentation for the Win32 API functions, structures, messages, and common controls used for building graphical user interfaces in Windows applications. Understanding these elements is fundamental to developing robust and interactive Windows desktop applications.
The Win32 API offers a rich set of tools for creating windows, dialog boxes, menus, buttons, edit fields, and other standard UI elements. It allows for detailed control over the appearance, behavior, and interaction of these components.
Key UI Control Functions
The following are some of the most commonly used Win32 API functions for managing UI controls:
| Function Name | Description |
|---|---|
CreateWindowEx |
Creates an overlapping, top-level window or a child window. |
DestroyWindow |
Destroys the specified window. |
GetDlgItem |
Retrieves a handle to a specified control in a dialog box. |
SendMessage |
Sends the specified message to a window or windows. |
PostMessage |
Places a message in the message queue of the specified thread and returns without waiting for the thread to process the message. |
SetWindowText |
Changes the text of the specified window's title bar (if it has one) and its class‐name entry in the window list. |
GetWindowText |
Copies the text of the specified window's title bar (if it has one) to the specified buffer. |
Important UI Structures
These structures are often used in conjunction with UI functions to pass or receive information:
| Structure Name | Description |
|---|---|
RECT |
Defines a rectangle. |
POINT |
Defines a point. |
MSG |
Contains message information from a thread's message queue. |
WNDCLASS |
Defines the window class attributes that are registered by the RegisterClass function. |
Common UI Control Messages
Applications use Windows messages to communicate with controls and to receive notifications from them. Some common messages include:
| Message Name | Control Type | Description |
|---|---|---|
WM_COMMAND |
All | Sent when a control is activated or when a menu item is selected. |
WM_GETTEXT |
Edit, Static, Button, Combobox, Listbox | Requests the text associated with a control. |
WM_SETTEXT |
Edit, Static, Button, Combobox, Listbox | Sets the text of a control. |
WM_CLICK |
Button | Sent when a button is clicked (often via WM_COMMAND). |
WM_CHAR |
Edit, Combobox, Listbox | Sent when a character key is pressed. |
Commonly Used Controls
The Win32 API provides a set of standard controls that can be used to build user interfaces:
- Buttons: Standard buttons, checkbox buttons, radio buttons.
- Edit Controls: Single-line and multi-line text input fields.
- Static Controls: Labels, bitmaps, and group boxes.
- List Boxes: Display a list of strings from which the user can select one or more items.
- Combo Boxes: A combination of a list box and an edit control, allowing the user to either type an item or select one from the list.
- Scroll Bars: Provide a means for navigating through information that is too large to be displayed entirely.
- Menus: Provide commands to the user.
- Dialog Boxes: Independent windows that typically contain controls for specific tasks.
For more advanced UI elements, consider exploring the Common Controls Library (ComCtl32.dll), which offers features like tree views, list views, progress bars, and tab controls.