GetDlgItemInt returns 0 - c++

I have a dialog and a picture control inside of it. During OnInitDialog I try to obtain the text part of the picture control like this
CWnd *dialogHandle; // Handle of the dialog
CWnd *itemHandle; // Handle of the picture control
BOOL error;
dialogHandle->GetDlgItemInt(itemHandle->GetDlgCtrlID(), &error, 0);
however GetDlgItemInt function set error to 0 which says there is an error
here is the resource line
CONTROL 65443, IDC_PICTURE, "Static", SS_BITMAP, 13, 13, 40, 40
I want this number 65443

You want GetWindowLong(hWnd, GWL_ID); (or the MFC equivalent).
GetDlgItemInt() is simply an atoi() wrapper around GetDlgItemText(), which reads the label of the control, not its ID.

GetDlgItemInt() is supposed to get a text out of control. The second parameter is referred to as 'translated' flag and not an 'error' flag. Is this realy the method you are looking for? I think you need something else.

Related

Use A Parameter In A .rs Resource File C++ Console

There is a similar question here but I'm looking for a C++ version.
I want to create a .rs file with a DialogBox that uses a string as a variable instead a " " so I can change it in the program.
For example: In
DEFPUSHBUTTON "Hello World", IDOK, 8, 24, 75, 14
the "Hello World" would become a variable name, which I can 'define' or set in the program.
Why? I'm trying to make a DialogBox, like a 'template', and make many instances around the program with different Text in but same buttons in them.
Hope my gibberish is understanded.
Unfortunately, this is not possible. The caption text for a control must be a constant string because the resource file is actually compiled separately from your application and has no knowledge of variables defined elsewhere in your program's code.
Resource files do support string tables, but even these require the strings to be constant values. The advantage is that you can modify the resource file without access to the rest of the source code, which makes things like localization possible, even by outside translators.
So you're stuck hard-coding the initial caption of your DEFPUSHBUTTON. It can be an empty string or whatever value you want; you just need a placeholder. And you can put all of the possible captions in a string table (which I would recommend), but you cannot link the two using any automated mechanism.
You need to write the code to do this yourself. You could certainly dynamically generate resources, but that's quite a bit of trouble. I think the simplest way of doing this is just to create the dialog (using your "template" resource file), retrieve the handle of the controls whose caption text you want to change, and send them a WM_SETTEXT message with the new string. In fact, the SetDlgItemText function will do exactly this for you.
Perhaps that would be easier to explain with some code. Assume that you have a dialog resource defined, including all of your controls. All of the controls you wish to modify will need to have a unique ID assigned to each of them so that you can distinguish between them at runtime. It doesn't matter what the initial values you assign in the resource file are, as you're going to be changing them right off the bat. It might look like this:
IDD_TEMPLATE DIALOG DISCARDABLE 0, 0, xx, xx
STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION
CAPTION "Dialog Template"
FONT 8, "MS Sans Serif"
BEGIN
CTEXT "Placeholder text", IDC_MESSAGE, xx, xx, xx, xx
DEFPUSHBUTTON "Placeholder", IDOK, xx, xx, xx, xx
PUSHBUTTON "Cancel", IDCANCEL, xx, xx, xx, xx
END
Then, in your dialog procedure (DialogProc), handle the WM_INITDIALOG message as follows:
INT_PTR CALLBACK TemplateDialogProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch (uMsg)
{
case WM_INITDIALOG:
{
// Load the caption strings you want to use from the string table
// in the resource file, or get them from wherever you want.
// These are the "variables" you wanted to use in the question.
TCHAR* pszMessage;
LoadString(hInstance, /* instance handle for app or resource DLL */
IDS_MESSAGE, /* ID of the string resource to load */
reinterpret_cast<LPTSTR>(&pszMessage),
0);
TCHAR* pszOkBtn;
LoadString(hInstance, IDS_OKBUTTON, reinterpret_cast<LPTSTR>(&pszOkBtn), 0);
// ...etc.
// Set the caption text for each control.
SetDlgItemText(hwndDlg, /* handle to the dialog box window */
IDC_MESSAGE, /* ID of the control to modify */
pszMessage); /* variable containing text to set */
SetDlgItemText(hwndDlg, IDOK, pszOkBtn);
// ...etc.
// And, if you want to set some other properties, you can do that too.
// For example, you might set the caption of the dialog itself.
TCHAR* pszTitle;
LoadString(hInstance, IDS_DLGCAPTION, reinterpret_cast<LPTSTR>(&pszTitle), 0);
SetWindowText(hwndDlg, pszTitle);
// ...etc.
return TRUE; // set the default focus
}
// ...process other messages as necessary
}
return FALSE; // we did not process the message
}
While I think Cody Gray's answer is better, there is always the option of creating your dialog template in-memory, and modifying it as you create new instances of the dialog. I wouldn't recommend it unless you find this kind of thing fun (I'm one of those people). I certainly wouldn't recommend it for what you're asking, but it is technically an option...
DialogBoxIndirect takes a pointer to a structure that is made up of a header (DLGTEMPLATE) that describes the dialog box itself, followed by the specified number of controls (DLGITEMTEMPLATE).
Effectively you can use the above to build a new in-memory dialog template each time you want a DialogBox with different text on the button. However, that's a little extreme if all you really want to do is change some text, which as Cody says, you can do with SetDlgItemText.
If you're really curious, here's an example.

Getting Resource Id from dialog Item

I put a picture control to a dialog, and did this settings
Misc->Type->Bitmap
Misc->Image->999
now in the OnInitDialog function of the dialog, I catched CWnd* of the picture control and I want to obtain a handle to either image I assign to the controller or image's id (which is 999)
How can I do this ?
thank you for your help.
CONTROL 65443, IDC_TRUSS_CTRL, "Static", SS_BITMAP, 13, 13, 517, 212
to be more precise about the problem, I want the number 65443 I've got the dialog's handle which holds this control and I also got the handle of the IDC_TRUSS_CTRL
what I do is:
bool error;
dialogWnd->GetDlgItemInt(controlWnd->GetDlgCtrlID(), &error, 0);
however error is 0 which means it encounter an error :\
You can get a CBitmap pointer from the control casting to a CStatic instead of CWnd:
CStatic *pPictureCtrl = (CStatic*)GetDlgItem( PICTURE_CONTROL_ID ); //Notice is the control resources ID not the Image resources ID
CBitmap *pBitmap = pPictureCtrl->GetBitmap();
But this won't be of much help depending on what you want to do with it (?).

How to create controls at runtime?

How to create dynamic MFC controls and handle message maps of the controls at runtime?
It really depends on which controls do you want to create, especially if you want to know which flags should you set. In general it goes down to this:
Normally a CWnd-derived control is created using Create or CreateEx. For a CButton, for instance:
CButton button;
button.Create("Button text", WS_CHILD | WS_VISIBLE | WS_TABSTOP | BS_PUSHBUTTON | DT_CENTER, CRect(5, 5, 55, 19), this, nID);
where the CRect specifies the button position, this is a pointer to the parent window, and nID is the control ID.
If the control doesn't come out as expected, it's probably because some flags are missing. I suggest you draw a sample control in design mode, check out the code for that control in the RC file, and copy the flags to the Create caller.
As for the message maps, they are normally routed to the parent window. The nID value you used in Create is important here, because it will be the number that identifies the control in the message map. If you have a fixed number of controls, you can hard-code the nID numbers for your controls (starting at 10000, for instance); if not, you'll have to provide a way for the parent window to identify them. Then you just add the message map entries.
ON_BN_CLICKED(10000, OnBnClicked)
ON_CONTROL_RANGE(BN_CLICKED, 10010, 10020, OnBtnsClicked)
You can use the ON_CONTROL_RANGE message map to map a range of IDs to the same function.

create a control programmatically using MFC

I just wonder how to do it.
I write :
CEdit m_wndEdit;
and in the button event handler (dialog app),
I write :
m_wndEdit.Create(//with params);
but I still don't see the control appear in the UI.
I actually wrote this in the button handler :
CWnd* pWnd = GetDlgItem(IDC_LIST1);
CRect rect;
pWnd->GetClientRect(&rect);
//pWnd->CalcWindowRect(rect,CWnd::adjustBorder);
wnd_Edit.Create(ES_MULTILINE | ES_NOHIDESEL | ES_READONLY,rect,this,105);
wnd_Edit.ShowWindow(SW_SHOW);
this->Invalidate();
id 105 doesn't exist. (I used it in the Create member function of CEdit). I just put it in there. isn't it supposed to be the id you want to give to the new control ? Should it already exist ?
Check with the following set of flags as the example mentioned in MSDN:
pEdit->Create(ES_MULTILINE | WS_CHILD | WS_VISIBLE | WS_TABSTOP | WS_BORDER | ES_NOHIDESEL | ES_READONLY,
rect, this, 105);
The Invalidate() is not necessary
Add the WS_VISIBLE flag to your create flags, you don't need the ShowWindow
You are creating the button on the location where IDC_LIST1 is - you probably want to do pWdn->Destroy() after the GetClientRect()
The id you pass to Create() can be anything, of course if you want to handle messages from this button later you'll need to use the correct id. In that case it's easiest to manually add an entry to resource.h.
What do you mean with 'I put this code in the button event handler' - which button? A different one from the one you're trying to create, I may hope? Does your code get called at all, does it stop when you put a breakpoint in? What's the value of wnd_Edit->m_hWnd after the call to Create()?
wnd_Edit is a member of your dialog, right, and not a a function local variable?
What is wnd_Edit exactly? If it's a local variable in that function, that is likely the problem. The CWnd destructor destroys the window associated with the CWnd. So when wnd_Edit goes out of scope, the edit box is destroyed too.
If that's not it, check the return value of Create(). Is it NULL? If it is, check the value of GetLastError().

How to autodetect urls in RichEdit 2.0?

When we have a RichEdit control and send it an EM_AUTOURLDETECT message with WPARAM set to TRUE, it nicely hightlights the detected URLs and sends the EN_LINK notifications.
But it does this only for text that is entered into the control. I haven't found the way to do it for text that's loaded into the control with SetWindowText or EM_STREAMIN.
Please help! Thanks
Upd:
I've created a test application from scratch and it works fine there. I think the problem might be that I have superclassed the control, that is, created a new window class and just use the window procedure of the original class. I'm gonna try subclassing the control instead..
I just knocked up a basic WTL dialog based app containing a riched20 control and the following works fine:
CRichEditCtrl richedit = GetDlgItem(IDC_RICHEDIT);
richedit.SetAutoURLDetect(TRUE);
richedit.SetWindowText(_T("http://www.stackoverflow.com"));
I have some old MFC code that does something similar, albeit with ES_STREAM, and it works OK too.
FWIW the WTL CRichEditCtrl wrapper is pretty thin. SetAutoURLDetect simply calls SendMessage passing it EM_AUTOURLDETECT.
I am compiling with _RICHEDIT_VER set to 0x0200 FWIW.
Without knowing the format of the text you are trying to add to the control with SetWindowText and EM_STREAMIN I'm going to take a guess and say this might have something to do with the control's text mode. After setting the contents of the control try sending it a EM_GETTEXTMODE message and see if the TM_PLAINTEXT bit is set. If this is the case then try sending a EM_SETTEXTMODE message followed by EM_AUTOURLDETECT. Your code should look something like this:
UINT textmode = (UINT)::SendMessage(handle_to_control, EM_GETTEXTMODE, 0, 0);
if(textmode & TM_PLAINTEXT) {
textmode &= ~TM_PLAINTEXT; // Clear the TM_PLAINTEXT bit
textmode |= TM_RICHTEXT; // Set the TM_RICHTEXT bit
if(::SendMessage(handle_to_control, EM_SETTEXTMODE, textmode, 0) != 0) {
// Failed to set the text mode
}
}
::SendMessage(handle_to_control, EM_AUTOURLDETECT, TRUE, 0);
You might just have to rewrite the text to the control to get it to re-parse.