widget looks different than the desinger when i run it

I'musing qt creator and using the designer to design my main window...
but when im using layouts to arrange my different objects (LineEdite , labels..etc ).. it look exatclly as i want it in the designer but we i run it the lineEidte get much smaller ... and also the window size is not in the same size i make it in the designer it is always bigger!!!!



other thing, Im using Scrollwidget and im dispalying some object on it and layout them all in the scrollwidget .. then i layout the scrollwidget in a groupbox

all look completely great in the designer but when i run it the scrollwidget shows the scrollbar in the side ... why it that ????? i have it set it with layout to fit exactly in it. so why it display it this way ??

thanks

I think the differences can come from two things. One is that a window gets system decorations that are different in size from the ones Designer uses. The other difference might come from the fact that widgets get real content that can influence their size. Why is that a big issue that you get a slightly different window size than you expected?