iOS---scrollview自动下移问题

- (void)loadScrollView

{

    // 禁止自动调整scrollview的内边距，防止scrollview下移64px

    self.automaticallyAdjustsScrollViewInsets =NO;

    

    self.mainScrollView = [[UIScrollViewalloc]initWithFrame:CGRectMake(0,120, SCREEN_WIDTH,SCREEN_HEIGHT-130)];

    self.mainScrollView.backgroundColor = [UIColorwhiteColor];

    self.mainScrollView.delegate =self;

    self.mainScrollView.pagingEnabled =YES;

    self.mainScrollView.showsVerticalScrollIndicator =NO;

    self.mainScrollView.showsHorizontalScrollIndicator =NO;

    [self.viewaddSubview: self.mainScrollView];

    

    self.mainScrollView.contentSize =CGSizeMake(SCREEN_WIDTH*self.titleArray.count,0);

}