Question concerning creating a DC, getting a ListBox's selected font, and invoking GetSystemMetrics(SM_SM_CXBORDER) about winsafe

[rodrigocfd]

Yes, it is possible.

In your C++ example, you used CClientDC, which is an MFC class that simply manages GetDC/ReleaseDC calls. In WinSafe, GetDC itself returns a guard which calls ReleaseDC, so the whole thing is transparent and you don't need to worry about it.

Your code has a mistake: you must save the old font returned by SelectObject and re-select it after using. This is also done automatically by a guard in WinSafe.

Another difference is that MFC calls GetTextExtent, but the actual Win32 function is GetTextExtentPoint32. They chose to rename it for some reason.

So, your translated code appears to be like this:

use winsafe as w;

let dc = my_list.hwnd().GetDC()?;

let f = my_list.hwnd().SendMessage(w::msg::wm::GetFont {}).unwrap();
let _old_font = dc.SelectObject(&f);

let mut sz = dc.GetTextExtentPoint32("my text")?;
sz.cx += 3 * w::GetSystemMetrics(co::SM::CXBORDER);
if sz.cx > width {
    width = sz.cx;
    my_list.hwnd().SendMessage(
        w::msg::lb::SetHorizontalExtent { width },
    );
}

[jerrywrice]

Rodrigo, Thanks, that is quite helpful. Best regards, Jerry W. Rice, Chief Technology Officer <http://www.FABNexus.com> www.FABNexus.com 660 Arboleda Drive Los Altos, CA 94024 Email: ***@***.***> ***@***.*** Cell: 650-207-8235 From: Rodrigo ***@***.***> Sent: Tuesday, February 28, 2023 10:21 AM To: rodrigocfd/winsafe ***@***.***> Cc: JWR_FABNexus ***@***.***>; Author ***@***.***> Subject: Re: [rodrigocfd/winsafe] Question concerning creating a DC, getting a ListBox's selected font, and invoking GetSystemMetrics(SM_SM_CXBORDER) (Issue #67) Yes, it is possible. In your C++ example, you used CClientDC, which is an MFC class <https://learn.microsoft.com/en-us/cpp/mfc/reference/cclientdc-class?view=msvc-170> that simply manages GetDC/ReleaseDC calls. In WinSafe, GetDC itself returns a guard which calls ReleaseDC, so the whole thing is transparent and you don't need to worry about it. Another difference is that MFC calls GetTextExtent, but the actual Win32 function is <https://learn.microsoft.com/en-us/windows/win32/api/wingdi/nf-wingdi-gettextextentpoint32w> GetTextExtentPoint32. They chose to rename it for some reason. So, your translated code appears to be like this: use winsafe as w; let dc = my_list.hwnd().GetDC()?; let mut sz = dc.GetTextExtentPoint32("my text")?; sz.cx += 3 * w::GetSystemMetrics(co::SM::CXBORDER); if sz.cx > width { width = sz.cx; my_list.hwnd().SendMessage( w::msg::lb::SetHorizontalExtent { width }, ); } — Reply to this email directly, view it on GitHub <#67 (comment)> , or unsubscribe <https://github.com/notifications/unsubscribe-auth/AEHOLCXVVA3UIVASEKYO2Y3WZY6ZTANCNFSM6AAAAAAVKGHWUQ> . You are receiving this because you authored the thread. <https://github.com/notifications/beacon/AEHOLCTLKE2FL4ZP2PXKCU3WZY6ZTA5CNFSM6AAAAAAVKGHWUSWGG33NNVSW45C7OR4XAZNMJFZXG5LFINXW23LFNZ2KUY3PNVWWK3TUL5UWJTSWLC7XS.gif> Message ID: ***@***.*** ***@***.***> >