CODEWITHSUNDEEP
winapi
Ben
Ben

Reputation: 556

The correct way of getting the parent window

The MSDN says the following about the GetParent function:

To obtain the parent window and not the owner, instead of using GetParent, use GetAncestor with the GA_PARENT flag.

But when calling GetAncestor(hWnd, GA_PARENT); for a window that doesn't have a parent, it returns the desktop window, while GetParent returns NULL.

So what is the correct way of getting a parent (and not the owner), and getting NULL if there are none?

Of course I could check whether GetAncestor returns the desktop window, but that seems like a hack to me.

Upvotes: 13

Views: 15655

Answers (3)

Robert Stevens
Robert Stevens

Reputation: 549

Updated in the year 2020 considering the latest Win32 documentation:

HWND GetRealParent(HWND hWnd)
{
    HWND hWndOwner;

    // To obtain a window's owner window, instead of using GetParent,
    // use GetWindow with the GW_OWNER flag.

    if (NULL != (hWndOwner = GetWindow(hWnd, GW_OWNER)))
        return hWndOwner;

    // Obtain the parent window and not the owner
    return GetAncestor(hWnd, GA_PARENT);
}

Upvotes: 7

user4780446
user4780446

Reputation: 11

A slightly better version that goes both "routes" and if it can't find a proper parent it will return the window itself(as to avoid null references). Using GetParent instead of GetAncestor worked in my case and returned the window I was after.

    public static IntPtr GetRealParent(IntPtr hWnd)
    {
        IntPtr hParent;

        hParent = GetAncestor(hWnd, GetAncestorFlags.GetParent);
        if (hParent.ToInt64() == 0 || hParent == GetDesktopWindow())
        { 
            hParent = GetParent(hWnd);
            if (hParent.ToInt64() == 0 || hParent == GetDesktopWindow())
            { 
                hParent = hWnd;
            }

        }

        return hParent;
    }

Upvotes: 1

Ben
Ben

Reputation: 556

Here's what I came up with:

//
// Returns the real parent window
// Same as GetParent(), but doesn't return the owner
//
HWND GetRealParent(HWND hWnd)
{
    HWND hParent;

    hParent = GetAncestor(hWnd, GA_PARENT);
    if(!hParent || hParent == GetDesktopWindow())
        return NULL;

    return hParent;
}

Upvotes: 12

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