Qscrollarea do not display scollbar and layouts pops out of place

I spent last night trying to get this QScrollArea to work without any luck. What I am trying to do is to add a top horizontal menu layout and a scrollable vertical content layout beneath the menu. The scrollbar is not visible and the content layout pops out of place as soon as I add new elements to it (by click one of the menu buttons).

Please help me out. :)

Regards, Lars Erik

import sys 
from PyQt4 import QtCore, QtGui, Qt 

class MainWindow( QtGui.QMainWindow ): 

    def __init__( self ): 

        QtGui.QMainWindow.__init__( self ) 

        self.centralWidget = QtGui.QWidget() 
        self.setCentralWidget( self.centralWidget ) 

        #Main Layout 
        layout = QtGui.QVBoxLayout() 
        layout.setSpacing( 0 )         
        self.centralWidget.setLayout( layout ) 

        #Top Menu Layout 
        hLayout = QtGui.QHBoxLayout() 
        layout.addLayout( hLayout ) 

        i = 0 
        while i < 5: 
            addContent = QtGui.QPushButton( 'Add Content' ) 
        开发者_高级运维    hLayout.addWidget( addContent ) 

            self.connect(addContent, QtCore.SIGNAL('clicked()'), self.addContent)             
            i += 1 

        #Content Layout 
        self.lowerWidget = QtGui.QWidget() 
        #self.lowerWidget.setMaximumSize( Qt.QSize(150, 250) ) 

        self.scrollArea = QtGui.QScrollArea() 
        self.scrollArea.setWidget( self.lowerWidget )           

        layout.addWidget( self.lowerWidget )   

        self.vLayout = QtGui.QVBoxLayout() 
        self.lowerWidget.setLayout( self.vLayout ) 

        i = 0 
        while i < 25: 
            label = QtGui.QLabel( 'Content' ) 
            self.vLayout.addWidget( label ) 
            i += 1             


    def addContent(self): 

        label = QtGui.QLabel( 'Content' ) 
        self.vLayout.addWidget( label ) 


if __name__ == '__main__': 

    app = QtGui.QApplication(sys.argv) 
    mainWin = MainWindow() 
    mainWin.show() 
    sys.exit(app.exec_())

---

This looks wrong:

self.scrollArea = QtGui.QScrollArea() 
self.scrollArea.setWidget( self.lowerWidget )           

layout.addWidget( self.lowerWidget )

You add lowerWidget to the scrollarea, just to add it to the layout in the next step, which removes lowerWidget from the scrollarea and reparent its top level widget. You must add the scrollarea to the layout:

self.scrollArea = QtGui.QScrollArea() 
self.scrollArea.setWidget( self.lowerWidget )       

layout.addWidget( self.scrollArea )