window jumps around

[Bonj]

Is there any reason why you shouldn't use CreateWindow in a DLL?
I've got an application that calls a function in a custom DLL from its
wndproc. In the DLL, I am creating a window using CreateWindow with
WS_POPUPWINDOW | WS_CAPTION | WS_CHILD, and displaying it modally (i.e.
executing a message pump in the DLL's function).
This works almost fine, i.e. the window displays and closes again and is
like a child popup window should be, but the window does 'jump around' a
bit, i.e. when you try to select the background (main app's) window, then
click on the caption of the child window, it does a little hop to another
area of the screen. Not far, but it's definitely more than the negligible
amount of dragging associated with the clicking. The DLL only registers its
wndclassex on the first call to it, after that, it just uses the same one. I
am also calling DestroyWindow on the child window before exiting the DLL
function.
I did rethink about the design of the app and decided that using
CreateDialog with a dialog resource might be better. (Also to that, is there
any reference on the commands used in the .rc file for the dialog resource?)
But I'm hesitant to, for fear the same thing may happen if I don't know
what's causing it, whereas if I can isolate the problem I can make sure it's
not due to the fact that it's in a DLL.

Thanks

[Steve Alpert]

Bonj wrote:

Is there any reason why you shouldn't use CreateWindow in a DLL?
I've got an application that calls a function in a custom DLL from its
wndproc. In the DLL, I am creating a window using CreateWindow with
WS_POPUPWINDOW | WS_CAPTION | WS_CHILD, and displaying it modally (i.e.
executing a message pump in the DLL's function).
This works almost fine, i.e. the window displays and closes again and is
like a child popup window should be, but the window does 'jump around' a
bit, i.e. when you try to select the background (main app's) window, then
click on the caption of the child window, it does a little hop to another
area of the screen. Not far, but it's definitely more than the negligible
amount of dragging associated with the clicking. The DLL only registers its
wndclassex on the first call to it, after that, it just uses the same one. I
am also calling DestroyWindow on the child window before exiting the DLL
function.

CreateWindow is just fine in a DLL. Perhaps you have other code in your
DLL that responds to WM_SIZE or WM_MOVE that is confusing client
coordinates with window coordinates?

/steveA
--
Steve Alpert
my email Fgrir_Nycreg @ vqk.pbz is encrypted with ROT13 (www.rot13.org)
and spaces

[Bonj]

nope, no other messages are handled, other than WM_CLOSE.

"Steve Alpert" wrote:

Bonj wrote:

Is there any reason why you shouldn't use CreateWindow in a DLL?
I've got an application that calls a function in a custom DLL from its
wndproc. In the DLL, I am creating a window using CreateWindow with
WS_POPUPWINDOW | WS_CAPTION | WS_CHILD, and displaying it modally (i.e.
executing a message pump in the DLL's function).
This works almost fine, i.e. the window displays and closes again and is
like a child popup window should be, but the window does 'jump around' a
bit, i.e. when you try to select the background (main app's) window, then
click on the caption of the child window, it does a little hop to another
area of the screen. Not far, but it's definitely more than the negligible
amount of dragging associated with the clicking. The DLL only registers its
wndclassex on the first call to it, after that, it just uses the same one. I
am also calling DestroyWindow on the child window before exiting the DLL
function.

CreateWindow is just fine in a DLL. Perhaps you have other code in your
DLL that responds to WM_SIZE or WM_MOVE that is confusing client
coordinates with window coordinates?

/steveA
--
Steve Alpert
my email Fgrir_Nycreg @ vqk.pbz is encrypted with ROT13 (www.rot13.org)
and spaces

[Norman Bullen]

Bonj wrote:

Is there any reason why you shouldn't use CreateWindow in a DLL?
I've got an application that calls a function in a custom DLL from its
wndproc. In the DLL, I am creating a window using CreateWindow with
WS_POPUPWINDOW | WS_CAPTION | WS_CHILD, and displaying it modally (i.e.
executing a message pump in the DLL's function).
This works almost fine, i.e. the window displays and closes again and is
like a child popup window should be, but the window does 'jump around' a
bit, i.e. when you try to select the background (main app's) window, then
click on the caption of the child window, it does a little hop to another
area of the screen. Not far, but it's definitely more than the negligible
amount of dragging associated with the clicking. The DLL only registers its
wndclassex on the first call to it, after that, it just uses the same one. I
am also calling DestroyWindow on the child window before exiting the DLL
function.
I did rethink about the design of the app and decided that using
CreateDialog with a dialog resource might be better. (Also to that, is there
any reference on the commands used in the .rc file for the dialog resource?)
But I'm hesitant to, for fear the same thing may happen if I don't know
what's causing it, whereas if I can isolate the problem I can make sure it's
not due to the fact that it's in a DLL.

Thanks

A window can't have both WS_POPUP and WS_CHILD styles.

You probably want only WS_POPUP since you have also specified WS_CAPTION.

Norm

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