Creating a Template in Memory - Win32 Programmer's Reference

Custom Search

Creating a Template in Memory

Applications sometimes adapt or modify the content of dialog boxes depending on the current state of the data being processed. In such cases, it is not practical to provide all possible dialog box templates as resources in the application's executable file. But creating templates in memory gives the application more flexibility to adapt to any circumstances.

In the following example, the application creates a template in memory for a modal dialog box that contains a message and OK and Help buttons.

In a dialog template, all character strings, such as the dialog box and button titles, must be Unicode strings. This example uses the MultiByteToWideChar function to generate these Unicode strings, because both Windows NT and Windows 95 support MultiByteToWideChar

The DLGITEMTEMPLATE structures in a dialog template must be aligned on DWORD boundaries. To align these structures, this example uses a helper routine that takes an input pointer and returns the closest pointer that is aligned on a DWORD (4 byte) boundary.

#define ID_HELP 150

#define ID_TEXT 200

LPWORD lpwAlign ( LPWORD lpIn)

{

ULONG ul;

ul = (ULONG) lpIn;

ul +=3;

ul >>=2;

ul <<=2;

return (LPWORD) ul;

}

LRESULT DisplayMyMessage(HINSTANCE hinst, HWND hwndOwner,

LPSTR lpszMessage)

{

HGLOBAL hgbl;

LPDLGTEMPLATE lpdt;

LPDLGITEMTEMPLATE lpdit;

LPWORD lpw;

LPWSTR lpwsz;

LRESULT ret;

int nchar;

hgbl = GlobalAlloc(GMEM_ZEROINIT, 1024);

if (!hgbl)

return -1;

lpdt = (LPDLGTEMPLATE)GlobalLock(hgbl);

// Define a dialog box.

lpdt->style = WS_POPUP | WS_BORDER | WS_SYSMENU

| DS_MODALFRAME | WS_CAPTION;

lpdt->cdit = 3; // number of controls

lpdt->x = 10; lpdt->y = 10;

lpdt->cx = 100; lpdt->cy = 100;

lpw = (LPWORD) (lpdt + 1);

*lpw++ = 0; // no menu

*lpw++ = 0; // predefined dialog box class (by default)

lpwsz = (LPWSTR) lpw;

nchar = 1+ MultiByteToWideChar (CP_ACP, 0, "My Dialog",

-1, lpwsz, 50);

lpw += nchar;

//-----------------------

// Define an OK button.

//-----------------------

lpw = lpwAlign (lpw); // align DLGITEMTEMPLATE on DWORD boundary

lpdit = (LPDLGITEMTEMPLATE) lpw;

lpdit->x = 10; lpdit->y = 70;

lpdit->cx = 80; lpdit->cy = 20;

lpdit->id = IDOK; // OK button identifier

lpdit->style = WS_CHILD | WS_VISIBLE | BS_DEFPUSHBUTTON;

lpw = (LPWORD) (lpdit + 1);

*lpw++ = 0xFFFF;

*lpw++ = 0x0080; // button class

lpwsz = (LPWSTR) lpw;

nchar = 1+MultiByteToWideChar (CP_ACP, 0, "OK", -1, lpwsz, 50);

lpw += nchar;

lpw = lpwAlign (lpw); // align creation data on DWORD boundary

*lpw++ = 0; // no creation data

//-----------------------

// Define a Help button.

//-----------------------

lpw = lpwAlign (lpw); // align DLGITEMTEMPLATE on DWORD boundary

lpdit = (LPDLGITEMTEMPLATE) lpw;

lpdit->x = 55; lpdit->y = 10;

lpdit->cx = 40; lpdit->cy = 20;

lpdit->id = ID_HELP; // Help button identifier

lpdit->style = WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON;

lpw = (LPWORD) (lpdit + 1);

*lpw++ = 0xFFFF;

*lpw++ = 0x0080; // button class atom

lpwsz = (LPWSTR) lpw;

nchar = 1+MultiByteToWideChar (CP_ACP, 0, "Help", -1, lpwsz, 50);

lpw += nchar;

lpw = lpwAlign (lpw); // align creation data on DWORD boundary

*lpw++ = 0; // no creation data

//-----------------------

// Define a static text control.

//-----------------------

lpw = lpwAlign (lpw); // align DLGITEMTEMPLATE on DWORD boundary

lpdit = (LPDLGITEMTEMPLATE) lpw;

lpdit->x = 10; lpdit->y = 10;

lpdit->cx = 40; lpdit->cy = 20;

lpdit->id = ID_TEXT; // text identifier

lpdit->style = WS_CHILD | WS_VISIBLE | SS_LEFT;

lpw = (LPWORD) (lpdit + 1);

*lpw++ = 0xFFFF;

*lpw++ = 0x0082; // static class

for (lpwsz = (LPWSTR)lpw;

*lpwsz++ = (WCHAR) *lpszMessage++;

);

lpw = (LPWORD)lpwsz;

lpw = lpwAlign (lpw); // align creation data on DWORD boundary

*lpw++ = 0; // no creation data

GlobalUnlock(hgbl);

ret = DialogBoxIndirect(hinst, (LPDLGTEMPLATE) hgbl,

hwndOwner, (DLGPROC) DialogProc);

GlobalFree(hgbl);

return ret;

}

Last news from Greatis Software

    Nostalgia .Net     .Net is powerful, but not all-powerful, so sometimes we need to use Win32 API for our .Net applications. It's simple enough with Platform Invoke if you have Win32 skill, but we do not always have time to dig the ancient documentation, declare the special types that are compatible with Win32, find the values of the Win32's constants and so on. Nostalgia .Net offers several simple-to-use classes, and components that will allow you to forget about the headache of Win32 and just use the power of Win32 in your application the same way as you use the native. Net classes. More »

Recommended software for developers

    Ultimate Pack     Component pack for Delphi and C++ Builder that contains runtime form designer, runtime object inspector, print suite and much more for the very special price. More »

    Form Designer .Net     Unique runtime form design solution that allows to edit any form in .Net WinForms application at runtime with full source codes for only 300 euro! More »

    Print Suite .Net     Print Suite .Net is a set of components for easy printing texts, images and grids from your WinForms applications. Full C# source codes are available More »

    Gradient Controls .Net     Gradient Controls .Net offers controls with gradient background feature. Labels, panels and so on... Full C# source codes are available More »

    Greatis iGrid     iGrid plots drawing grid right over your desktop, so you can use it everywhere, with any drawing application without any special plugins for different graphic editors. More »

All the contacts and projects

Dmitry Vasiliev (just.dmitry)

More Online Helps

Win32 Programmer's Reference
Win32 Multimedia Programmer's Reference
OLE Programmer's Reference
Microsoft Windows Pen API Programmer's Reference
Microsoft Windows Sockets 2 Reference
Microsoft Windows Telephony API (TAPI) Programmer's Reference
Unix Manual Pages

greatis just4fun network