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How to Process ComboBoxEx Notifications

  • Article

This topic demonstrates how to process ComboBoxEx notification messages.

What you need to know

Technologies

Prerequisites

  • C/C++
  • Windows User Interface Programming

Instructions

A ComboBoxEx control notifies its parent window of events by sending WM_NOTIFY messages. It also passes the WM_COMMAND notification messages that it receives from the combo box contained within it to the parent window to be processed. Therefore, your application must be prepared to process WM_NOTIFY messages from the ComboBoxEx and WM_COMMAND messages that are forwarded from the ComboBoxEx child combo box control.

The example in this section handles the WM_NOTIFY and WM_COMMAND messages from a ComboBoxEx control by calling a corresponding application-defined function to process these messages.

Complete example

LRESULT CALLBACK WndProc (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg){

        case WM_COMMAND: // notification from the child ComboBox within the ComboBoxEx control.
            if((HWND)lParam == g_hwndCB)
                DoOldNotify(hwnd,  wParam);  
            break;

        case WM_NOTIFY: // notification from the ComboBoxEx control
            return (DoCBEXNotify(hwnd, lParam));

        case WM_PAINT:
            hdc = BeginPaint(hwnd, &ps);
            EndPaint(hwnd, &ps);
            break;

        case WM_DESTROY:
            PostQuitMessage(0);
            break;

        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
            break;
    }

    return FALSE;
}

About ComboBoxEx Controls

ComboBoxEx Control Reference

Using ComboBoxEx Controls

ComboBoxEx