UIButton 随笔

1. 设置 UIButton 字体靠左对齐

   //体靠左对齐
 _navBackBtn.contentHorizontalAlignment =UIControlContentHorizontalAlignmentLeft;

2.设置UIButton字体靠右省略

      //字体靠右省略
    _navBackBtn.titleLabel.lineBreakMode =  NSLineBreakByTruncatingTail;