My application starts up another external application.
I want to remove the title bar of this external application once it has started.
Is this feasible, and
No need to inject anything, you can just modify the windows style bits as using the API, e.g. this works for Notepad, however YMMV depending on the app your playing with.
//Get current style
lCurStyle = GetWindowLong(hwnd, GWL_STYLE)
//remove titlebar elements
lCurStyle = lCurStyle And Not WS_CAPTION
lCurStyle = lCurStyle And Not WS_SYSMENU
lCurStyle = lCurStyle And Not WS_THICKFRAME
lCurStyle = lCurStyle And Not WS_MINIMIZE
lCurStyle = lCurStyle And Not WS_MAXIMIZEBOX
//apply new style
SetWindowLong hwnd, GWL_STYLE, lCurStyle
//reapply a 3d border
lCurStyle = GetWindowLong(hwnd, GWL_EXSTYLE)
SetWindowLong hwnd, GWL_EXSTYLE, lCurStyle Or WS_EX_DLGMODALFRAME
//redraw
SetWindowPos hwnd, 0, 0, 0, 0, 0, SWP_NOMOVE Or SWP_NOSIZE Or SWP_FRAMECHANGED