UIActivityViewController in iOS 7

UIActivityViewController in iOS 7

In my app i have added these lines of codes to incorporate the
functionality of uiactivityviewcontroller
UIImage *yourImage = someImg;
UIActivityViewController *activityVC = [[UIActivityViewController
alloc] initWithActivityItems:[NSArray
arrayWithObjects:@"abcdefgh",yourImage, nil]
applicationActivities:nil];
activityVC.excludedActivityTypes = @[ UIActivityTypeMessage
,UIActivityTypeAssignToContact,UIActivityTypeSaveToCameraRoll];
[self presentViewController:activityVC animated:YES completion:nil];
and UIActivityViewContoller working fine , but the UI is like this No FB
icon , No twitter icon
However it is showing perfect UI in iOS 6 . Could Any one tell the the
reason or the answer... Thanks in Advance ...