Edit Control Notification

I have a dialog box with 5 edit controls. I must be certain that all 5 controls have text before I enable an UPDATE button. Therefore, is there any way to monitor all 5 edit controls to verify that text has been entered in all 5 controls?

I was thinking along the lines of EN_SELCHANGE but I'm not sure on how to approach the problem. A "google" on the internet provides a couple examples but they're all in MFC which I don't really care for or totally understand.

Thanx

Bob

Possibilites include checking for an EN_CHANGE notification and then either:

• EnumChildWindows and check GetWindowTextLength on any edit control.
• check GetWindowTextLength on edit controls within a custom function.

Here's a quick example demonstrating the latter:

Code:

---

#include <windows.h>
#include <tchar.h>

#define NUM_EDITS 5

enum {
  IDC_EDIT1=100,
  IDC_EDIT2,
  IDC_EDIT3,
  IDC_EDIT4,
  IDC_EDIT5,
  IDC_BTN
};

BOOL SetButtonState(HWND *hwnds)
{
int i;

for (i=0;i<NUM_EDITS;++i)
  {
  if (GetWindowTextLength(hwnds[i])==0)
    {
    return FALSE;
    }
  }
return TRUE;
}

LRESULT CALLBACK WndProc(HWND hwnd,UINT uMsg,WPARAM wParam,LPARAM lParam)
{
static HWND hEdits[NUM_EDITS];
static HWND hBtn;

switch (uMsg)
  {
  case WM_COMMAND:
    {
    HWND hCntrl;
    WORD wID,wNotify;
   
    hCntrl=(HWND)lParam;
    wID=LOWORD(wParam);
    wNotify=HIWORD(wParam);
   
    if (hCntrl && wNotify==EN_CHANGE)
      {
      EnableWindow(hBtn,SetButtonState(hEdits));
      }
     
    return 0;
    }
  case WM_CREATE:
    {
    CREATESTRUCT *cs=(CREATESTRUCT*)lParam;
    int i;
   
    for (i=0;i<NUM_EDITS;++i)
      {
      hEdits[i]=CreateWindowEx(WS_EX_CLIENTEDGE,_T("edit"),_T(""),
                              WS_CHILD|WS_VISIBLE|WS_TABSTOP,
                              10,32*(i+1),200,30,hwnd,(HMENU)(IDC_EDIT1+i),
                              cs->hInstance,0);
      }
    hBtn=CreateWindowEx(0,_T("button"),_T("Enabled"),
                        WS_CHILD|WS_VISIBLE|WS_TABSTOP|WS_DISABLED,
                        10,40*(i+1),200,30,hwnd,(HMENU)(IDC_EDIT1*100),
                        cs->hInstance,0);
   
    SetFocus(hEdits[0]);
    return 0;
    }
  case WM_DESTROY:
    PostQuitMessage(0);
    return 0;
  default:
    return DefWindowProc(hwnd,uMsg,wParam,lParam);
  }
}

int WINAPI WinMain(HINSTANCE hInst,HINSTANCE hPrev,LPSTR pStr,int nCmd)
{
HWND      hwnd;
MSG        msg;
TCHAR      classname[]=_T("kenf's_wnd");
WNDCLASSEX wcx={0};

wcx.cbSize      =sizeof(wcx);
wcx.lpfnWndProc  =WndProc;
wcx.hInstance    =hInst;
wcx.hIcon        =(HICON)LoadImage(0,IDI_APPLICATION,IMAGE_ICON,0, 0,LR_SHARED);
wcx.hCursor      =(HCURSOR)LoadImage(0,IDC_ARROW,IMAGE_CURSOR,0,0, LR_SHARED);
wcx.hbrBackground=(HBRUSH)(COLOR_BTNFACE+1);
wcx.lpszClassName=classname;

if (RegisterClassEx(&wcx))
  {
  hwnd=CreateWindowEx(0,classname,
                      _T("5 Edits and a Button"),
                      WS_OVERLAPPEDWINDOW,
                      GetSystemMetrics(SM_CXSCREEN)/4,
                      GetSystemMetrics(SM_CYSCREEN)/4,
                      GetSystemMetrics(SM_CXSCREEN)/2,
                      GetSystemMetrics(SM_CYSCREEN)/2,
                      0,0,hInst,0);
  if (hwnd)
    {
    ShowWindow(hwnd,nCmd);
    UpdateWindow(hwnd);
   
    while (GetMessage(&msg,0,0,0)>0)
      {
      if (!IsDialogMessage(hwnd,&msg))
        {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
        }
      }
    return msg.wParam;
    }
  else
    {
    MessageBox(0,_T("Wnd creation failure"),_T("Error"),MB_OK|MB_ICONERROR);
    return 0;
    }
  }
MessageBox(0,_T("Wnd registration failure"),_T("Error"),MB_OK|MB_ICONERROR);
return 0;
}

---

There are very probably other ways of doing this but I hope that will be of some use to you.

Ken,

That's EXACTLY what I need.

Thanx

Bob