如何把SegmentedControl加到Navigation中间

UISegmentedControl *segmentedControl=[[UISegmentedControlalloc] initWithFrame:CGRectMake(80.0f,8.0f, 207.0f, 30.0f) ];  

    [segmentedControl insertSegmentWithTitle:@"关注"atIndex:0animated:YES];  

    [segmentedControl insertSegmentWithTitle:@"消息"atIndex:1animated:YES];  

    segmentedControl.segmentedControlStyle =UISegmentedControlStyleBar;  

    segmentedControl.momentary = YES;  

    segmentedControl.multipleTouchEnabled=NO;  

    [segmentedControl addTarget:selfaction:@selector(segmentClick:)forControlEvents:UIControlEventValueChanged]; 

    

    self.mySegment=segmentedControl;

    self.mySegment.selectedSegmentIndex=0;

    [[self navigationItem]setTitleView:segmentedControl];