VC Tips Summary of the dialog box skills _c language

This paper collects and summarizes the VC in the dialog box commonly used in some of the skills for VC development due to a certain reference value.

1. How to modify the background color of the dialog box:

In the OnPaint () function of the dialog box, add the following statement:

CRect rect;
GetClientRect (&rect);   Calculates the size of the dialog box
DC. Fillsolidrect (&rect,rgb (192,248,202));  Draw a dialog box background color

2. How to make the pop-up dialog box have a unified background color:

Add the following statement to the InitInstance () function of the application class Cxxxapp:

SetDialogBkColor (RGB (192,248,202));

All user-defined pop-up dialogs have a background color of RGB (192,248,202) and do not need to be set individually.

3. How to open a file dialog box to make a number of choices:

When you customize the Open File dialog box, you can add the Ofn_allowmultiselect property to the Open File dialog box to make multiple selections.
Such as:

CFileDialog M_dlg (TRUE, NULL, NULL, OFN_HIDEREADONLY | Ofn_overwriteprompt
    | Ofn_allowmultiselect, NULL, NULL);
After that, use the getstartposition () function to get the selected starting file location and use the Getnextpathname () function to get the file names at each location.
such as:
if (m_dlg.domodal () = = Idok)
{
   POSITION pos;
   pos = M_dlg.getstartposition ();
   while (POS)
   {
     M_path = M_dlg.getnextpathname (POS);
     ......
   }

4. Why does the file not open when you select multiple files to a certain number with the Open File dialog box?

CFileDialog sets a buffer for the file list, and when too many files are selected, a buffer overflow occurs, causing some files to not be opened. Can be solved by using a custom large buffer instead of a system buffer.
Such as:

CFileDialog M_dlg (TRUE, NULL, NULL, OFN_HIDEREADONLY | Ofn_overwriteprompt
    | Ofn_allowmultiselect, NULL, NULL);/Custom Open File dialog box
char* pBuf = new char[20480];    Application buffer
m_Dlg.m_ofn.nMaxFile = 20480;    Let PBuf replace CFileDialog buffer
m_Dlg.m_ofn.lpstrFile = PBuf;
M_dlg.m_ofn.lpstrfile[0] = NULL;
....... delete []pbuf;    Reclaim buffers

5. Prompt dialog box (MessageBox)

You can use the MessageBox () function pop-up prompt dialog box in the View class and dialog class using the MFC function. This function prototype is:

int MessageBox (LPCTSTR lpsztext,lpctstr lpscaption=null,uint NTYPE=MB_OK);

Parameters:
Lpsztext Displays the string
Lpscaption dialog box title
Ntype style, which can be a combination of the following values:
Specifies one of the following flags to display a button in a message box, which has the following meaning.
Mb_abortretryignore: The message box contains three buttons: Abort,retry and ignore.
MB_OK: Message box contains a button: OK. This is the default value.
Mb_okcancel: Message box contains two buttons: OK and cancel.
Mb_retrycancel: The message box contains two buttons: Retry and Cancel.
Mb_yesno: Message box contains two buttons: Yes and No.
Mb_yesnocancel: The message box contains three buttons: Yes,no and Cancel. The
specifies one of the following flags to display the icon in the message box: The meaning of the flag is as follows.
Mb_iconexclamation:
mb_iconwarning: An exclamation point appears in a message box.
Mb_iconinformation:
Mb_iconasterisk: An icon in a circle that writes the letter I appears in a message box.
Mb_iconouestion: An issue flag icon appears in the message box.
Mb_iconstop:
Mb_iconerror:
Mb_iconhand: A Stop message icon appears in a message box. The

Specifies one of the following flags to specify the default button: The meaning of the flag is as follows.

Mb_defbutton1: The first button is the default button. If Mb_defbutton2,mb_defbutton3,mb_defbutton4 is not specified, the Mb_defbutton1 is the default value. The
Mb_defbutton2, and the second button is the default button.
Mb_defbutton3: The third button is the default button.
Mb_defbutton4: The fourth button is the default button.

Example: Prompt file for disk:

int t;
The text of T=messagebox (m_pathname+) has changed, do you want to save it? "," Warning ", Mb_yesnocancel | mb_iconwarning);
if (t==0 | | t==idcancel) return
  ;
if (t==idyes)
  onfilesave ();

You cannot use the MessageBox () function in MFC in other classes, such as document classes, and you can only use the MessageBox () function in an API function:

int MessageBox (HWND hwnd,lpctstr lpsztext,lpctstr lpcaption,uint utype);

HWnd: Identifies the owning window of the message box that will be created. If this parameter is NULL, the message box does not have a window.
The latter three parameters are the same as the MessageBox of the view class, but there is no default value and must be set.
Cases:

:: MessageBox (null,m_pathname+) text has changed, to save it? "," Warning ", Mb_yesnocancel | mb_iconwarning);