Drop-down box

How can I make a drop-down box like in browsers? I know, how to make listboxes...

Damn, I always ask 1 minute before I find the answer by myself. I didn't know they are called "combo boxes"...
But still, it works only when I use it with some listbox styles:

Code:

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f1=CreateWindowEx(0,"Combobox","The first one",WS_BORDER|WS_VISIBLE|WS_CHILD|LBS_STANDARD|LBS_USETABSTOPS,10,10,100,200,hwnd,(HMENU)25554,GetModuleHandle(NULL),NULL);

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Without LBS_STANDARD it won't display correctly...

How can I get the data of the currently selected string?

Code:

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MessageBox(hwnd,(char*)SendMessage(f1,CB_GETITEMDATA,SendMessage(f1,CB_GETCURSEL,0,0),0),TEXT("hello"),MB_OK);

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Doesn't seem to work...
Tried this too:

Code:

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char* happy;
happy=(char*)SendMessage(f1,CB_GETCURSEL,0,0);
SendMessage(f1,CB_GETLBTEXT,(WPARAM)happy,(LPARAM)happy);
MessageBox(hwnd,happy,TEXT("hello"),MB_OK);

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But this crashes my program...
Ok tested a bit and found a working way:

Code:

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int tap;
char hello[256];
tap=(int)SendMessage(f1,CB_GETCURSEL,0,0);
SendMessage(f1,CB_GETLBTEXT,(WPARAM)tap,(LPARAM)happy);
MessageBox(hwnd,happy,TEXT("hello"),MB_OK);

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GetWindowText() will work fine with combo boxes. ;)

good call on that GetWindowText( ) function.. was just having the same problem.. but now I can easily extract selected text from my combo box :)

Code:

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#include <windows.h>

#define ID_LIST 1
#define ID_TEXT 2

/*  Declare Windows procedure  */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);

/*  Make the class name into a global variable  */
char szClassName[ ] = "ComboBox App";

int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)

{
    HWND hwnd;              /* This is the handle for our window */
    MSG messages;            /* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */

    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style = CS_DBLCLKS;                /* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);

    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;                /* No menu */
    wincl.cbClsExtra = 0;                      /* No extra bytes after the window class */
    wincl.cbWndExtra = 0;                      /* structure or the window instance */
    /* Use Windows's default color as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;

    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;

    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
          0,                  /* Extended possibilites for variation */
          szClassName,        /* Classname */
          "ComboBox App",      /* Title Text */
          WS_OVERLAPPEDWINDOW, /* default window */
          CW_USEDEFAULT,      /* Windows decides the position */
          CW_USEDEFAULT,      /* where the window ends up on the screen */
          544,                /* The programs width */
          375,                /* and height in pixels */
          HWND_DESKTOP,        /* The window is a child-window to desktop */
          NULL,                /* No menu */
          hThisInstance,      /* Program Instance handler */
          NULL                /* No Window Creation data */
          );

    /* Make the window visible on the screen */
    ShowWindow (hwnd, nFunsterStil);

    /* Run the message loop. It will run until GetMessage() returns 0 */
    while (GetMessage (&messages, NULL, 0, 0))
    {
        /* Translate virtual-key messages into character messages */
        TranslateMessage(&messages);
        /* Send message to WindowProcedure */
        DispatchMessage(&messages);
    }

    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    return messages.wParam;
}


//User Defined Function(s)

//Compare the efficiency of my C++ function vs. Charles Petzold's C function 
//Page #407
void FillListBox(HWND hwndList)
{
    TCHAR *pVarName[] = {"Item1", "Item2", "Item3", "Item4", "Item5"};
   
    for(int i=0; i<5; i++)
 
            SendMessage(hwndList, CB_ADDSTRING, 0, (LPARAM)pVarName[i]);
   
}
           



/*  This function is called by the Windows function DispatchMessage()  */

LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static HWND hwndList, hwndText;
    int iIndex, iLength, cxChar, cyChar;
    TCHAR pVarName[30];
       
   
       
    switch (message)                  /* handle the messages */
    {
   
        case WM_CREATE:
           
            cxChar = LOWORD(GetDialogBaseUnits());
            cyChar = HIWORD(GetDialogBaseUnits());
           
          //Create Display Window
          hwndText = CreateWindow(TEXT("static"),NULL, WS_CHILD | WS_VISIBLE |
                                  SS_LEFT, cxChar, cyChar,
                                  GetSystemMetrics(SM_CXSCREEN), cyChar,
                                  hwnd, (HMENU)ID_TEXT,
                                  (HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE),
                                  NULL);
           
          //Create ComboBox
          hwndList =  CreateWindow(TEXT("Combobox"), NULL, WS_CHILD | WS_VISIBLE |
                                  LBS_STANDARD, cxChar, cyChar*3,
                                  cxChar*16 + GetSystemMetrics(SM_CXVSCROLL),
                                  cyChar*5, hwnd, (HMENU)ID_LIST,
                                  (HINSTANCE)GetWindowLong(hwnd, GWL_HINSTANCE),
                                  NULL);
                                     
            //Populate ComboBox
            FillListBox(hwndList);
           
            //Set a Default Selection
            SendMessage(hwndList, CB_SETCURSEL, 0, 0);
            GetWindowText(hwndList, pVarName, 30);
            SetWindowText(hwndText, pVarName);
           
            return 0;
           
        case WM_COMMAND:
           
            if( LOWORD(wParam)==ID_LIST && HIWORD(wParam)==CBN_SELCHANGE)
            {
                //Get Selection from Combo Box               
                GetWindowText(hwndList, pVarName, 30);     
               
                //Show Text in Display Window
                SetWindowText(hwndText, pVarName);
            }
               
            return 0;   
         
        case WM_DESTROY:
           
            PostQuitMessage (0);      /* send a WM_QUIT to the message queue */
            break;
       
        default:
                                      /* for messages that we don't deal with */
            return DefWindowProc (hwnd, message, wParam, lParam);
    }

    return 0;
}

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Well, I used this method to set a default selection:

Code:

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SendMessage(hwndCombobox,CB_SETCURSEL,0,0);

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Hi, as that topic was on the front page and the author siemed to have found the solution I didn't want to creater a new topic, with almost the same point...How can I import text file contents, as and example:

Cat
Dog
Cow

To combo box?
This is porbably a rather stupid question, but I'd still be happy, if somebody would take his or her time to answer it...
Best regards,
dogbert234.

Quote:

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Originally Posted by The Brain

Code:

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...

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To "The Brain", thanks for posting that code. It helped me by clearing up some confusion I had.

Quote:

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Originally Posted by dogbert234

How can I import text file contents, as an example:

Cat
Dog
Cow

To combo box?

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dogbert, good question. If you can read in those words from a file, then you should be able to take "The Brain"'s example code to do it.

Can you write a program to simply read in those words?

If you need more help, I will be glad to help.

(Big hint: read and understand the function "FillListBox()")

Dogbert, I am pretty sure, that you want it to take the whole line from the file so this is the code:

Code:

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#include <windows.h>
#include <stdio.h>
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
HWND combo;
FILE * pFile;
char run[256];
char szClassName[ ] = "WindowsApp";

int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)

{
    HWND hwnd;
    MSG messages;
    WNDCLASSEX wincl;

    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;
    wincl.style = CS_DBLCLKS;
    wincl.cbSize = sizeof (WNDCLASSEX);

    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;
    wincl.cbClsExtra = 0;
    wincl.cbWndExtra = 0;
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;

    if (!RegisterClassEx (&wincl))
        return 0;

    hwnd = CreateWindowEx (
          0,
          szClassName,
          "Windows App",
          WS_OVERLAPPEDWINDOW,
          CW_USEDEFAULT,
          CW_USEDEFAULT,
          544,
          375,
          HWND_DESKTOP,
          NULL,
          hThisInstance,
          NULL
          );

    ShowWindow (hwnd, nFunsterStil);

    while (GetMessage (&messages, NULL, 0, 0))
    {
        TranslateMessage(&messages);
        DispatchMessage(&messages);
    }
    return messages.wParam;
}

LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
        case WM_CREATE:
            combo=CreateWindowEx(0,"Combobox","",
            WS_BORDER|WS_VISIBLE|WS_CHILD|LBS_STANDARD|LBS_USETABSTOPS|CBS_AUTOHSCROLL,
            10,10,200,200,hwnd,
            (HMENU)25554,GetModuleHandle(NULL),NULL);
            pFile = fopen ("text.txt" , "r");
            if(pFile==NULL){
            MessageBox(hwnd,"Could not open file","Problem",MB_OK);
            }
            else{
            while(fgets(run,100,pFile)){
            if(run[strlen(run)-1]=='\n'){
            run[strlen(run)-1]='\0';
            }
            SendMessage(combo,CB_ADDSTRING,0,(LPARAM)run);
            }
            SendMessage(combo,CB_SETCURSEL,0,0);
            }
            break;
        case WM_DESTROY:
            PostQuitMessage (0);
            break;
        default:
            return DefWindowProc (hwnd, message, wParam, lParam);
    }

    return 0;
}

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maxorator,

Excellent.

I had a problem with "LBS_USE TABSTOPS", which should be "LBS_USETABSTOPS".

Theres a wierd thing about these spaces. When I copy it to this textbox it is ok, but when I post the code, some spaces appear...
I've seen it in many posts in this forum.