Capture Hidden window with aero effects

Question

I am trying to capture windows hidden behind my application. I am using windows 7 and VC++. I have tried printwindow() function which draws the both non-client and client area of hidden window, but captured window in the device context doesn't show desktop composition effects(aero effects). Instead it shows the captured window with windows 7 basic theme.

I have also tried with GetWindowDC() to retrive the DC of hidden window, and then Bitblt() it to memory DC but the captured window doesn't show non-client area (caption, close button, minimize button etc) correctly.

Anybody faced this issue? Please help.

Answer 1

Click the link below. It leads to a MSDN site that lists all the existing Windows Functions ever of all history since Windows 95 up to Windows 8 (from period where Microsoft started Windows until present). It shows old windows functions of first Windows and new windows functions added for the new windows.

http://msdn.microsoft.com/en-us/library/windows/desktop/ff468919(v=vs.85).aspx

Anyway follow this site. You will see the name of each function as a link. Click any of them that you are interested. Each link there leads to another MSDN site that explains all the basics knowledge that you must know about the function before using it, that you want to learn more. What that function does, its purpose, all its parameters and how to use each one, all their flags, all parameters types, return value and at last remarks section that shed more light and sometimes gives tips about the selected function.

Of course, you don't have to read all of them. Find in the list only the necessary functions to fit your needs. The functions that will solve your problem and answer your question that you posted.

By the way, I read your post, and I think that I found in the list the necessary functions that will do what you want to do, I will list them below, and say in one sentence what each does for what you need:

AnimateWindow - Enables you to produce special effects when showing or hiding windows. There are four types of animation: roll, slide, collapse or expand, and alpha-blended fade.

FlashWindow - Flashes the specified window one time. It does not change the active state of the window.

FlashWindowEx - Flashes the specified window specified number of times. It does not change the active state of the window.

Use these functions to achieve the aero effects that you want.

SetWindowPos - Changes the size, position, and Z order of a child, pop-up, or top-level window. These windows are ordered according to their appearance on the screen. The topmost window receives the highest rank and is the first window in the Z order.

Use this function to show the hidden windows on the top side (above all other windows) and on the screen front of you. The operating system will automatically draw the both non-client and client area of these windows without using any gdi, draw and paint functions yourself.

If you want these windows to return back to their previous state (where they were hidden), then save their state with GetWindowPlacement function and later call SetWindowPlacement to bring them back to their hidden state. You can try GetWindowRect and SetWindowPos instead to achieve the same goal.

I also think that you will be interested in GetWindowTheme and SetWindowTheme functions and all the draw theme functions (BackgroundEx, Edge, Icon, Text, TextEx).

There are more theme functions. Find in msdn and in other sites on the web.