Place a window behind any other existing third party window

Question

In order to take a screenshot of a specific window, I need to place a white colored TForm behind that window. What Windows API could I use to change the z-order of my window and place it correctly ?

Answer 1

Try the SetWindowPos() function.

Answer 2

On Delphi you can useSendToBack method, .Top and .Left properties.

form1.Top := ...;
form1.Left := ...;
form1.SendToBack;

procedure SendToBack;

Description

Use SendToBack to change the order of overlapping controls or forms.

The order in which controls stack on top of each other (also called the Z order) depends on the order the controls are placed on the form. For example, if you put a label and an image on a form so that one is on top of the other, the one that was placed first on the form becomes the one on the bottom. Because both the label and the image are non-windowed controls, they "stack" as you would expect them to. Call the SendToBack method for the top object to move it below the other object.

The stacking order of two windowed controls is the same as the stacking of two non-windowed controls. For example, if you put a memo on a form, then put a check box on top of it, the check box remains on top. Calling SendToBack for the check box makes the memo appear on top.

The stacking order of windowed and non-windowed controls cannot be mingled. For example, if you put a memo, a windowed control, on a form, and then put a label, a non-windowed control, on top of it, the label disappears behind the memo. Windowed controls always stack on top of non-windowed controls. In this example, calling the SendToBack method of the memo does nothing, the label remains behind the memo.

If the control has the input focus when the SendToBack method executes, it loses the input focus.

(Edit: WinSnap is a very good utility for taking and editing screenshots)

Answer 3

If you can get the handle of the window you want in front then I would assume that: Pseudo Code:

MyAppWindow.BringToFront

followed by

TargetWindow.BringToFront

Should have the desired effect, yes?