Adding to the System Menu For Your Window
Introduction
Sometimes it's nice to be able to add your own capabilities to the system menu on a window. In this example, the menu entry restores the original size of the window.
The .h File Additions
private: // User declarations
void __fastcall WMSysCommand(Messages::TWMSysCommand
&Msg); // special handling for the system menu entries
public:
void __fastcall Dispatch(void *Message)//
Provide special handling for the system menu entries
{
switch (((PMessage)Message)->Msg)
{
case
WM_SYSCOMMAND:
WMSysCommand(*((Messages::TWMSysCommand
*)Message));
break;
default:
TForm::Dispatch(Message);
break;
};
};
Additions To The Form Constructor
const String MenuString = "Original Size";
MENUITEMINFO info =
{
sizeof(MENUITEMINFO),
MIIM_TYPE | MIIM_STATE | MIIM_ID ,
MFT_STRING,
MFS_ENABLED,
IDS_CUSTOMID,
NULL,
NULL,
NULL,
0,
MenuString.c_str(),
0
}; // last item not used
// obtain the menu handle for the system menu
HMENU SysMenu = GetSystemMenu(Handle, FALSE);
// Insert the new menu item just after the close menu item. If the 3rd arg
// is TRUE, the menu item is inserted after the menu item listed in the
// second arg. FALSE puts the new item before the specified menu id.
InsertMenuItem (SysMenu, SC_CLOSE, TRUE, &info);The Handler For System Menu Items In The Form .cpp
//---------------------------------------------------------------------------
void __fastcall Form1::WMSysCommand(TWMSysCommand &Msg)
{
if (Msg.CmdType == IDS_CUSTOMID)
{
Width = OriginalWidth; // Collected in Loaded()
Height = OriginalHeight;
Msg.Result = true;
}
else
{
TForm::Dispatch(&Msg);
};
}Conclusion
Yeah, it's not too hard, is it? Though there aren't many situations where you need it, this technique can come in handy.