Package com.sun.jna.platform.win32

# Interface WinUser.WindowProc

All Superinterfaces:
  `AltCallingConvention`, `Callback`, `StdCall`, `StdCallLibrary.StdCallCallback`

Enclosing interface:
  WinUser

public static interface WinUser.WindowProc extends StdCallLibrary.StdCallCallback
An application-defined function that processes messages sent to a window. The WNDPROC type defines a pointer to this callback function. WindowProc is a placeholder for the application-defined function name.

## Nested Class Summary

## Nested classes/interfaces inherited from interface com.sun.jna.Callback

`Callback.UncaughtExceptionHandler`

## Field Summary

### Fields inherited from interface com.sun.jna.Callback

`FORBIDDEN_NAMES, METHOD_NAME`

## Method Summary

Modifier and Type
Method
Description
`WinDef.LRESULT`
`callback(WinDef.HWND hwnd, int uMsg, WinDef.WPARAM wParam, WinDef.LPARAM lParam)`

## Method Details

### callback

WinDef.LRESULT callback(WinDef.HWND hwnd, int uMsg, WinDef.WPARAM wParam, WinDef.LPARAM lParam)

Parameters:
  `hwnd` - [in] Type: HWND A handle to the window.
  `uMsg` - [in] Type: UINT The message. For lists of the system-provided messages, see System-Defined Messages.
  `wParam` - [in] Type: WPARAM Additional message information. The contents of this parameter depend on the value of the uMsg parameter.
  `lParam` - [in] Type: LPARAM Additional message information. The contents of this parameter depend on the value of the uMsg parameter.
Returns:
  the lresult