Re: How do you add items to a combobox? - C / C++ / MFC Discussion Boards

Paul M Watt5-May-02 19:54

5-May-02 19:54

So let me get this clear, you are painting the background and text in the menu, but ...

A) you never see the text appear on the menu

B) you see the text appear on the menu, but the next time it appears the text is gone

First, I would say that if you are painting the background in the OnPaint handler, then you need to handle the OnEraseBkgnd handler as well and simply return TRUE in your implmentation of this function.

second if your answer to the above statement is choice A, I would say make sure that you are drawing in the proper coordinates for you window. It is possible that you have miscalculated the region that you should be drawing and you are not drawing on a region where the menu window exists.

If your answer is B, then I will have to ask some more questions.

Good Luck!

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

Re: ReleaseDC is not working

Paul M Watt5-May-02 9:36

Paul M Watt

5-May-02 9:36

If you want the data for a DC from a window to be persistent after you call ReleaseDC, then you need to create your window with the CS_OWNDC or CS_CLASSDC style.

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

Re: ReleaseDC is not working

MaTrIX2k25-May-02 11:09

MaTrIX2k2

5-May-02 11:09

is not working either Confused | :confused:

Re: ReleaseDC is not working

Paul M Watt5-May-02 19:56

Paul M Watt

5-May-02 19:56

Based on your reply to PJ Arends response, the styles of your window are not the problem. I responded to the other thread, I hope that helps you.

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

How do you add items to a combobox?

5-May-02 7:00

I have this combobox that i want to add some items to, but nothing is added when i do this:

for (int i = 0;i < 147;i++)
	SendMessage(DlgItems[5], CB_ADDSTRING, 0L, (LPARAM)gszGenres[i]);

DlgItems[5] equals the hwnd of the control and gszGenres is a global char array with 148 items.

WHat am i doing wrong?

thanks

Re: How do you add items to a combobox?

Tom Archer5-May-02 7:32

Tom Archer

5-May-02 7:32

I just did what you're trying to do, but you don't mention a few things so I had to improvise in my declarations.

Here's how I declares my array of HWNDs

static struct 
{
  int id;
} combos [] = {
IDC_COMBO1, IDC_COMBO2, IDC_COMBO3, IDC_COMBO4, IDC_COMBO5, IDC_COMBO6};
HWND DlgItems[6];

I then initialize them like this:

for (int i = 0; i < sizeof combos / sizeof combos[0]; i++)
  DlgItems[i] = ::GetDlgItem(GetSafeHwnd(), combos[i].id);

I created an array of strings like this:

static struct 
{
  char sz[10];
} gszGenres [] = {
"1", "2", "3", "4", "5", "6", "7", "8", "9", "10", 
"11", "12", "13", "14", "15", "16", "17", "18", "19", "20", 
"21", "22", "23", "24", "25", "26", "27", "28", "29", "30", 
"31", "32", "33", "34", "35", "36", "37", "38", "39", "40", 
"41", "42", "43", "44", "45", "46", "47", "48", "49", "50", 
"51", "52", "53", "54", "55", "56", "57", "58", "59", "60", 
"61", "62", "63", "64", "65", "66", "67", "68", "69", "70", 
"71", "72", "73", "74", "75", "76", "77", "78", "79", "80", 
"81", "82", "83", "84", "85", "86", "87", "88", "89", "90", 
"91", "92", "93", "94", "95", "96", "97", "98", "99", "100", 
"101", "102", "103", "104", "105", "106", "107", "108", "109", "110", 
"111", "112", "113", "114", "115", "116", "117", "118", "119", "120", 
"121", "122", "123", "124", "125", "126", "127", "128", "129", "130", 
"131", "132", "133", "134", "135", "136", "137", "138", "139", "140", 
"141", "142", "143", "144", "145", "146", "147", "148"};

Finally, the code to load the combo box:

for (int i = 0; i < sizeof gszGenres / sizeof gszGenres[0]; i++)
  ::SendMessage(DlgItems[5], CB_ADDSTRING, 0L, (LPARAM)gszGenres[i].sz);

Cheers,
Tom Archer
Author, Inside C#
Author, Visual C++.NET Bible

A total abstainer is one who abstains from everything but abstention, and especially from inactivity in the af

Re: How do you add items to a combobox?

5-May-02 7:43

I don't use all that MFC stuff. Do you know how to do it without MFC? here's what i do:

HWND DlgItems[6];

DlgItems[5] = GetDlgItem(hWnd, IDC_GENRES);

and then initialize the strings like this (up to number 147)

char gszGenres[148][23];

strcpy(gszGenres[0], "Blues");
strcpy(gszGenres[1], "Classic Rock");
strcpy(gszGenres[2], "Country");
strcpy(gszGenres[3], "Dance");

... etc.

and then add them like a wrote before...

Re: How do you add items to a combobox?

Tom Archer5-May-02 8:00

Tom Archer

5-May-02 8:00

What MFC stuff? I defined two static structs, called the Win32 SDK function ::GetDlgItem to fill the hwnd struct and then called the Win32 SDK function ::SendMessage to send the CB_ADDSTRING message. The only MFC you see here is the call to GetSafeHwnd becuase I don't know from where you're calling the ::GetDlgItem function. You can obviously replace that with however you get the hwnd for your dialog.

Cheers,
Tom Archer
Author, Inside C#
Author, Visual C++.NET Bible

A total abstainer is one who abstains from everything but abstention, and especially from inactivity in the af

Re: How do you add items to a combobox?

5-May-02 8:07

Oh, sorry, i see, we're doing exactly the same... does your work?

Re: How do you add items to a combobox?

Tom Archer5-May-02 8:15

Tom Archer

5-May-02 8:15

No problem. My app is an MFC app, but I'm using Win32 SDK calls to mimic your environment. Yes, the data shows up exactly as it should.

Cheers,
Tom Archer
Author, Inside C#
Author, Visual C++.NET Bible

A total abstainer is one who abstains from everything but abstention, and especially from inactivity in the af

Re: How do you add items to a combobox?

5-May-02 8:32

Then i simply don't understand it. I have also tried just passing (LPARAM)"hello" to the lparam, and nothing happens...

Strange...

5-May-02 8:38

strange, when i use the CB_GETCOUNT message to get the number of items in the combobox, it says 147, but nothing shows up in the box...

Even more strange...

5-May-02 8:44

When i send the WM_SETTEXT message and pass for example "Rock" to the lparam, it selects it and it appears...

And...

5-May-02 8:50

I just checked if my WndProc recieved the CBN_DROPDOWN message (the message sent when the list is about to be expanden ie. dropped down) and it doesen't get the message...

Re: Strange...

Tom Archer5-May-02 8:45

Tom Archer

5-May-02 8:45

What happens when you do a CB_SETCURSEL?

Cheers,
Tom Archer
Author, Inside C#
Author, Visual C++.NET Bible

A total abstainer is one who abstains from everything but abstention, and especially from inactivity in the af

Re: Strange...

5-May-02 9:14

It works "Acid Punk"... number 3...

Re: Strange...

Tom Archer5-May-02 9:38

Tom Archer

5-May-02 9:38

This tells me that your drop down is too small.

Laugh | :laugh:

Sorry. I just read how that can be taken.

Anyway, this thread should help you in determing how to, er, lengthen your drop down.

Cheers,
Tom Archer
Author, Inside C#
Author, Visual C++.NET Bible

A total abstainer is one who abstains from everything but abstention, and especially from inactivity in the af

Re: How do you add items to a combobox?

Nish Nishant5-May-02 9:26

Nish Nishant

5-May-02 9:26

Tom Archer wrote:
What MFC stuff?

LOL
I can imagine how you just stood there stunned.
I mean you type in a post, two pages long and then he says this Smile | :)

Nish

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Re: How do you add items to a combobox?

Tom Archer5-May-02 9:42

Tom Archer

5-May-02 9:42

He's probably used to getting MFC replies even though he's requested a Win32 solution.

Cheers,
Tom Archer
Author, Inside C#
Author, Visual C++.NET Bible

A total abstainer is one who abstains from everything but abstention, and especially from inactivity in the af

Re: How do you add items to a combobox?

Nish Nishant5-May-02 9:56

Nish Nishant

5-May-02 9:56

Tom Archer wrote:
He's probably used to getting MFC replies even though he's requested a Win32 solution.

Yeah Smile | :)

Possible.
Of course maybe he remembers how a guy here asked a CString question and suddenly another *guy* asks him if he is using MFC Smile | :)

Nish

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Re: How do you add items to a combobox?

Ravi Bhavnani6-May-02 14:30

Ravi Bhavnani

6-May-02 14:30

This has nothing to do with answering your question, but you might find this link helpful!

/ravi

"There is always one more bug..."
http://www.ravib.com
ravib@ravib.com

Re: How do you add items to a combobox?

Shog⁹5-May-02 7:42

Shog⁹

5-May-02 7:42

Anonymous wrote:
WHat am i doing wrong?

I don't know. But here are some things to check:

If it is not already, gszGenres should be defined something like this:

const char* gszGenres[] = 
{
   "Rock",
   "Heavy Metal",
   "Ancient ('70s) Rock",
   "Fake ('80s) Rock",
   "Industrial",
   "Trance",
   "Trip Hop",
   "Rap",
   "Baroque",
   "Blues",
   // ...
   "Pop"
};
const int nNumGenres = sizeof(gszGenres)/sizeof(char*);

If there are really 148 strings in gszGenres, then this loop will skip one, since it only loops 147 times (i = 0 to 146). If you use the code above, you can use nNumGenres to avoid hard-coding this value.
How is DlgItems defined? Can you avoid hard-coding indices somehow?
Are you positive DlgItems[5] is the correct HWND? Put in a breakpoint and check.

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Change screen resolution...!

BlackSmith5-May-02 5:57

BlackSmith

5-May-02 5:57

How to change screen resolution programmatically
(instead of 'Display properties->Settings')? Ha?

10X Yoll!

--BlackSmith--

"With the help of all mighty", 2002, Me.

Re: Change screen resolution...!

Nish Nishant5-May-02 9:29

Nish Nishant

5-May-02 9:29

ChangeDisplaySettings

Nish

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Re: Change screen resolution...!

Ravi Bhavnani6-May-02 14:27

Ravi Bhavnani

6-May-02 14:27

See this article.

/ravi

"There is always one more bug..."
http://www.ravib.com
ravib@ravib.com

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