Thread: Keyboard & TextBox WM_KEYDOWN

Hello

Does anyone know how to properly associate key messages using the WM_KEYDOWN case in the message procedure?
This is what I have so far (relevant code colored in green):

Code:

#include <windows.h>
#define TextBoxDefined   101

// Message Queue Commands to be defined later
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);

//WinMain() instead of main()
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
 //Window class
    WNDCLASSEX wc;
    //Window class parameters
    wc.cbSize        = sizeof(WNDCLASSEX); //???
    wc.style         = 0; //???
    wc.lpfnWndProc   = WndProc; //???
    wc.cbClsExtra    = 0; //???
    wc.cbWndExtra    = 0; //???
    wc.hInstance     = hInstance; //???
    wc.hIcon         = LoadIcon(NULL,IDI_APPLICATION); //Executable's desktop icon
    wc.hCursor       = LoadCursor(NULL, IDC_ARROW); //Cursor
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1); //Window color
    wc.lpszMenuName  = NULL; //No menu
    wc.lpszClassName = "WindowClass"; //???
    wc.hIconSm       = LoadIcon(NULL, IDI_APPLICATION); //Window icon? , Sm = small?

    if(!RegisterClassEx(&wc)) //error handling
    {
        MessageBox(NULL, "Registration Failure", "Error", MB_OK); //Okay button
        return 0; //return fail
    }

    ////////////////////////////////////////////////////////////////////////////

 //The actual window
    HWND MyParentWindow;
    //The window's parameters
    MyParentWindow = CreateWindowEx(
        0, //Style
        "WindowClass",
        "Title", //Title
        WS_OVERLAPPEDWINDOW, //minimize, maximize, close
        0,//position x in pixels relative to screen
        0,//position y in pixels relative to screen
        500,//size x dimension in pixels
        500,//size y dimension in pixels
        NULL, //MyParentWindow is the parent window and it does not have a parent, thus NULL
        NULL, //no menu was defined
        hInstance, //???
        NULL); //???

    if(MyParentWindow == NULL) //error handling
    {
        MessageBox(NULL, "MyParentWindow Creation Failure", "Error", MB_OK); //okay button
        return 0;
    }

    ShowWindow(MyParentWindow, nCmdShow); //show the window called "MyParentWindow"
    UpdateWindow(MyParentWindow); //update the window called "MyParentWindow"

    ////////////////////////////////////////////////////////////////////////////

 // Message loop
    MSG Msg;
    //GetMessage() gets a message from message queue.
    while(GetMessage(&Msg, NULL, 0, 0) > 0) //while there are more than 0 messages?
    {
        TranslateMessage(&Msg); //???
        DispatchMessage(&Msg); //???
    }
    return Msg.wParam; //return "wParam" of Msg???
}

//Messages to be interpreted
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg) // if&else commands to follow when interpreting the current message in queue
    {
        case WM_CREATE:
        {
            HWND TextBox;
            TextBox = CreateWindowEx(WS_EX_CLIENTEDGE,
                                   "EDIT",
                                   "Predefined Text",
                                   WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_HSCROLL | ES_MULTILINE | ES_AUTOVSCROLL | ES_AUTOHSCROLL,
                                   0,
                                   0,
                                   0,
                                   0,
                                   hwnd,
                                   (HMENU)TextBoxDefined,
                                   GetModuleHandle(NULL),
                                   NULL);
            if(TextBox == NULL)
                MessageBox(hwnd, "Text Box creation failed", "Error", MB_OK | MB_ICONERROR);

            HFONT hfDefault;
            hfDefault = (HFONT)GetStockObject(DEFAULT_GUI_FONT);

            SendMessage(TextBox, WM_SETFONT, (WPARAM)hfDefault, MAKELPARAM(FALSE,0));
        }
        break;
        
        case WM_SIZE:
        {
            HWND TextBox;
            TextBox = GetDlgItem(hwnd, TextBoxDefined);
            
            RECT FullWindow;
            GetClientRect(hwnd, &FullWindow);
            SetWindowPos(TextBox, //"TextBox" is being positioned
                         NULL,
                         0,
                         0,
                         FullWindow.right,
                         FullWindow.bottom,
                         SWP_NOZORDER);
        }
        break;

        case WM_KEYDOWN:
            switch (wParam)
            {
                case VK_CONTROL: //if control is pressed
                {
                    switch(wParam)
                    {
                        case VK_DELETE: //if delete is pressed
                        {
                            //if CTRL DEL are pressed
                            SetDlgItemText(hwnd, TextBoxDefined, "Blah Blah Blah"); //write BlahBlahBlah
                            return 0;
                        }
                        break;
                    }
                    return 0;
                }
                break;
            }
            return 0;
        break;
        
        case WM_CLOSE:
            DestroyWindow(hwnd);
        break;
        case WM_DESTROY:
            PostQuitMessage(0);
        break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}

I am using Dev C++ and the code should compile as is.
It opens up a window with a textbox. The textbox has predefined text.
I was wondering how I could either retrieve the text currently in the textbox, or set new text onto it after the user pressed something like CTRL+DEL.
I tried a WM_COMMAND (for a menu bar) and it successfully set the text. It also switched on the wParam, which I believe is the correct Param for WM_KEYDOWN too.
The code compiles and yet it doesn't do what I want, which is weird. I'm sure it's incomplete somehow.

Any leads would help

Anything with concrete examples would be greatly appreciated.
Thanks in advance!

Your delete case will never be reached because wParam cannot be equal to VK_CONTROL and VK_DELETE at the same time. I suggest a flag variable which you can set when control is pressed, and then when the delete key is pressed you can check to see if the flag is set.

This also entails processing the WM_KEYUP message (to unset the flag variable).