iOS小知识

1.UIScrollView下沉

    self.automaticallyAdjustsScrollViewInsets = NO;

2.裁剪圆角无效  layer.cornerRadius

    headImage.layer.masksToBounds = YES;

    headImage.clipsToBounds = YES;

3.按钮标题左对齐

  [btnObj setContentHorizontalAlignment:UIControlContentHorizontalAlignmentLeft];

4.给window添加视图无效

[[[UIApplication sharedApplication] delegate] window]    用这个对象去添加视图

5.UITableview 表头跟随一起移动

    [[UITableView alloc]initWithFrame:self.view.frame style:UITableViewStyleGrouped];