want to make ok button trigger, since it on a dialog

[Malek]

good evening everybody ..

In my project,I have created a dialog for Authentication.
When the user fill the auth text boxes, I want to transfer his data to the main window.
When I try to make that by ok button trigger, they give me this message:

The class definition of "UI::Dialog could not be found in home/Malek/Desktop/ConTest-auth/mainwindow.cpp"

I try to make #include for some file names but without response.

When I try to make trigger in the mainwindow,I dont have this problem.
So,I have think about make swap between mainwindow and auth dialog i.e. put auth dialog in main window and put mainwindow in another dialog.
But this will be the last choice ,also this way will Prevents the user from log off and log on again.

can you help me?

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I also want to put a picture in my project and make it Clickable and zoomable.
But until now I want only to learn about put a pic simply.
please give me the party string..
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Thanks

[squidge]

Could be various things. Post more code.

Try the header code first.

[Malek]

There is no code.
Even when I open new project and try to make button event handler ,this problem faced me.
Anyway, I have Tried more than one time on more than one project until one of them give responce.

Thank you expert fatjuicymole for your interest.

I now will switch to the picture issue.Can you help me!!