Three questions : mainwindow background image,case sensitivity and push button image

[qtnewbie12]

1st: I can assume that you don't use qrc, that's way Qt can't resolve resource. see The Qt Resource System.
2nd: correct spelling of the enum is Qt::CaseSensitivity enum.

Thank you ,I used qrc and now the image appear but the problem now is that the image is appearing as a tile I mean its repeating itself all over the form .How can I make it appear normally ?

[spirit]

See full reference about background property. Try to set Repeat to no-repeat.