How to make the dialog box receive the WM_CHAR message (Windows Programming)

As we all know, the dialog box sometimes cannot capture the WM_CHAR message. For example, you want to change all the Edit controls in the dialog box to uppercase. We do not hesitate to write:

 

  # Include
// Declare the Dialog Procedure

Bool callback DialogProc (HWND, UINT, WPARAM, LPARAM );

Int WINAPI WinMain (

HINSTANCE hInstance, // handle to current instance

HINSTANCE hPrevInstance, // handle to previous instance

LPSTR lpCmdLine, // pointer to command line

Int nCmdShow // show state of window

)

{

Int ret = DialogBoxParam (hInstance, MAKEINTRESOURCE (IDD_DIALOG1), NULL, DialogProc, 0 );

Return (ret! = IDOK );

}

Bool callback DialogProc (

HWND hwndDlg, // handle to dialog box

UINT uMsg, // message

WPARAM wParam, // first message parameter

LPARAM lParam // second message parameter

){

HWND hWndEdit;

Switch (uMsg ){

Case WM_INITDIALOG:

// Get a handle to the edit control

HWndEdit = GetDlgItem (hwndDlg, IDC_EDIT1 );

Return TRUE;

Break;

Case WM_CHAR:

WParam = toupper (wParam );

Break;

Case WM_COMMAND:

Switch (LOWORD (wParam )){

Case IDOK:

Case IDCANCEL:

// Close the dialog

EndDialog (hwndDlg, LOWORD (wParam ));

}

Return TRUE;

}

Return FALSE;

}

Sorry, I am sure you will fail. Why is the problem on WM_CHAR? You can try it. When you do not move the cursor to the Edit Control, the dialog box can be captured.

WM_CHAR message, but once you move the cursor to the Edit Control, WM_CHAR cannot be captured.

In this case, how can we capture WM_CHAR? I want to program MFC in a small Case. I just need to reload PreTranslateMessage.

However, for Windows programming, it is a little troublesome to use APIs. Here I provide two methods to convert them into uppercase.

1) capture the WM_CHAR message. In this case, the WMC_CHAR is not captured in the dialog box. If you don't need to talk about it, provide the code. Let's take a look.

# Include
// Declare the Dialog Procedure

Bool callback DialogProc (HWND, UINT, WPARAM, LPARAM );

Lresult callback NewEditProc (HWND, UINT, WPARAM, LPARAM );

// Define a gloabal var

WNDPROC g_Edit;

Int WINAPI WinMain (

HINSTANCE hInstance, // handle to current instance

HINSTANCE hPrevInstance, // handle to previous instance

LPSTR lpCmdLine, // pointer to command line

Int nCmdShow // show state of window

)

{

Int ret = DialogBoxParam (hInstance, MAKEINTRESOURCE (IDD_DIALOG1), NULL, DialogProc, 0 );

Return (ret! = IDOK );

}

Bool callback DialogProc (

HWND hwndDlg, // handle to dialog box

UINT uMsg, // message

WPARAM wParam, // first message parameter

LPARAM lParam // second message parameter

){

HWND hWndEdit;

Switch (uMsg ){

Case WM_INITDIALOG:

HWndEdit = GetDlgItem (hwndDlg, IDC_EDIT1 );

// Subclass the Edit control

G_Edit = (WNDPROC) SetWindowLong (hWndEdit, GWL_WNDPROC, (LONG) NewEditProc );

Return TRUE;



Case WM_COMMAND:

Switch (LOWORD (wParam )){

Case IDOK:

Case IDCANCEL:

EndDialog (hwndDlg, LOWORD (wParam ));

}

Return TRUE;

}

Return FALSE;

}

Lresult callback NewEditProc (HWND hwnd, UINT message,

WPARAM wParam, LPARAM lParam)

{

TCHAR chCharCode;

Switch (message)

{

Case WM_CHAR:

WParam = toupper (wParam );

Break;

}

Return CallWindowProc (g_Edit, hwnd, message, wParam, lParam );

}

2) The second method is a bit earthy, but it is a good way to achieve the goal. Provide the original code.

# Include
// Declare the Dialog Procedure

Bool callback DialogProc (HWND, UINT, WPARAM, LPARAM );

Int WINAPI WinMain (

HINSTANCE hInstance, // handle to current instance

HINSTANCE hPrevInstance, // handle to previous instance

LPSTR lpCmdLine, // pointer to command line

Int nCmdShow // show state of window

)

{

Int ret = DialogBoxParam (hInstance, MAKEINTRESOURCE (IDD_DIALOG1), NULL, DialogProc, 0 );

Return (ret! = IDOK );

}

Bool callback DialogProc (

HWND hwndDlg, // handle to dialog box

UINT uMsg, // message

WPARAM wParam, // first message parameter

LPARAM lParam // second message parameter

){

HWND hWndEdit;

Switch (uMsg ){

Case WM_INITDIALOG:

HWndEdit = GetDlgItem (hwndDlg, IDC_EDIT1 );

Return TRUE;



Case WM_COMMAND:

Switch (LOWORD (wParam )){

Case IDC_EDIT1:

If (HIWORD (wParam) = EN_CHANGE)

{

TCHAR szString [100] = {0 };

GetDlgItemText (hwndDlg, IDC_EDIT1, szString, 99 );

Int nLen = 0;

Int index = 0;

NLen = lstrlen (szString );

For (index = 0; index {

If (szString [index] <= 'Z' & szString [index]> = 'A ')

{

SzString [index]-= 32;

}

}

SzString [nLen] = 0;

 

SendMessage (GetDlgItem (hwndDlg, IDC_EDIT1), WM_SETTEXT, (WPARAM) 0, (LPARAM) (LPCSTR) szString );

SendMessage (GetDlgItem (hwndDlg, IDC_EDIT1), EM_SETSEL, lstrlen (szString), lstrlen (szString ));

}

Break;

Case IDOK:

Case IDCANCEL:

EndDialog (hwndDlg, LOWORD (wParam ));

}

Return TRUE;

}

Return FALSE;

}

All of the above are passed on VC6.0