WinAPI: Create resizable window without title bar,

2020-02-07 17:13发布

问题:

If you look at the windows of the browsers Firefox, Chrome or Opera, you'll notice that their windows

  • have minimize/maximize/close buttons
  • are resizable
  • but have no title bar

I'm interested: how can I create such a window?

What I have already tried:

I looked around on StackOverflow (and googled, too), and found this: opening a window that has no title bar with win32

Unluckily, this didn't help completely:

The first step was to extend the solution proposed on opening a window that has no title bar with win32

hWnd = CreateWindow(szWindowClass, szTitle, WS_BORDER, 
  CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, 
  NULL, NULL, hInstance, NULL);

SetWindowLong(hWnd, GWL_STYLE, WS_SIZEBOX);
// See remarks on http://msdn.microsoft.com/en-us/library/windows/desktop/ms633545.aspx
SetWindowPos(hWnd, 0, 
   0, 0, 0, 0, // Position + Size
   SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_FRAMECHANGED);

Of course, this delivers no minimize/maximize buttons, but on the other hand, if I want minimize/maximize buttons, I have to do:

SetWindowLong(hWnd, GWL_STYLE, WS_SIZEBOX | WS_MAXIMIZEBOX | 
    WS_MINIMIZEBOX | WS_SYSMENU | WS_CAPTION);

Why does this combination seem to be necessary? First I probably want WS_MAXIMIZEBOX | WS_MINIMIZEBOX since I want these buttons.

But http://msdn.microsoft.com/en-us/library/ms632600.aspx says that if I set one of WS_MAXIMIZEBOX and WS_MINIMIZEBOX, I also have to set WS_SYSMENU. And when I set WS_SYSMENU, I also have to set WS_CAPTION but this is not what I want, because I wanted to avoid the title bar (indeed: if WS_CAPTION is not set, no minimize/maximize buttons are shown).

So what is to do?

回答1:

The programs remove the non-client area (the title bar) and have a bunch of custom handling for reproducing the window buttons, icons, system menu etc. The benefit of this is that they can draw to the new "title bar", which is actually part of the standard client area, adding tabs or other custom controls.

The following two articles will show you how to do this on Vista and above (using the DWM):

  • Setting up a custom title bar on Windows Vista / 7
  • Setting up a custom title bar - reprise This one has a demo app showing the result of a number of variations / options.

This is very complex to do and get right, so the above two articles are invaluable. The author must have put a lot of work into them! Both links have example code written in Delphi, but it should be easy enough to translate it to C++ - the concepts are identical, it's just syntax.

You might also be interested in general resources on Glass and DWM, since it's all closely related. You'll spot the above two links included in that list :)



回答2:

You can create a window with or without caption - whatever is more appropriate from the point of view of desired customization (that is "without" is you want to do it "without title bar" as you say), and the important wart is that you take over painting non-client area - this is the key thing.

At this point, there is no one to paint your mimimize/maximize buttons already. It does not however mean that you have to do the painting right from scratch and mimic standard UI. There is DrawFrameControl and friends API where you can use DFCS_CAPTIONMIN argument and have minimize button painted for you. You will also want to respond to other non-client area messages, e.g. handle WM_NCHITTEST to tell Windows where your new window buttons are.

You might also want to check Visual Styles Reference to leverage theme-enabled drawing API such as DrawThemeBackground.

A simple example of this activity is putting an additional button onto caption, such as described in detail here: CCaptionButton (buttons for the titlebar).



回答3:

I believe they create a normal window and then paint over the title bar with their custom widgets/tabs. This is evident in Firefox, as when it hangs you can see the normal Windows title bar appear over the tabs.