The only requirement is that you must have already created the parent window because you must pass a valid handle to the parent window when creating the child window. Depending on the design of the framework, this may or may not be a valid place to create child windows. Some frameworks implement a two-phase style of construction for window objects. In cases like this, you cannot create child windows inside of the parent window's constructor because the parent window has not yet been created and you do not have a valid handle to use when creating the children.
If the creation of either fails, an exception will be thrown. Otherwise, you can be sure that you have access to a valid window handle inside the body of your derived class's constructor. But that's just a personal preference and a matter of individual style. Different people have different ideas about how much work should be done inside of a constructor. My personal litmus test is that, after the constructor has run, you should have a valid, fully usable object on which any member functions can be called.
I don't much care for two-phase construction, because I don't like the interface complexity that introduces of requiring the consumer to not only create the object, but also call a Create or Init method. I don't consider child windows to be an integral part of the parent, though, so I say that their creation belongs elsewhere than in the parent's constructor.
For your needs you are not interested in these non-client messages. If an application processes this message, it should return TRUE to continue creation of the window. Sent when an application requests that a window be created by calling the CreateWindowEx or CreateWindow function. The message is sent before the function returns. The window procedure of the new window receives this message after the window is created, but before the window becomes visible. If an application processes this message, it should return zero to continue creation of the window.
This device context includes the window title bar, menu, scroll bars, and frame in addition to the client area. Applications programs rarely use the GetWindowDC function. Are you needing to put a button on the non-client area? I believe one of the parameters you can pass to your CreateWindow Stack Overflow for Teams — Collaborate and share knowledge with a private group. Skip to main content. This browser is no longer supported.
Download Microsoft Edge More info. Contents Exit focus mode. Note To write code that is compatible with both bit and bit versions of Windows, use the SetWindowLongPtr function. Is this page helpful? Yes No. The margin inset values determine how far to extend the frame on the four sides of the window.
This ensures that frame extension is handled properly when the window is at its default size and when it is maximized. The following image shows a standard window frame on the left and the same window frame extended on the right. The visual difference between these two windows is very subtle. The only difference between the two is that the thin black line border of the client region in the window on the left is missing from the window on the right.
The reason for this missing border is that it is incorporated into the extended frame, but the rest of the client area is not. For the extended frames to be visible, the regions underlying each of the extended frame's sides must have pixel data with an alpha value of 0. The black border around the client region has pixel data in which all color values red, green, blue, and alpha are set to 0.
The rest of the background does not have the alpha value set to 0, so the rest of the extended frame is not visible. The easiest way to ensure that the extended frames are visible is to paint the entire client region black.
The following image shows the same standard frame left and extended frame right shown previously. After you have extended the frame of your application and made it visible, you can remove the standard frame.
Removing the standard frame enables you to control the width of each side of the frame rather than simply extending the standard frame. By doing so, your application uses the entire window region as the client area, removing the standard frame.
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