UITableHeaderViewAutoLayout

应用：

• TableHeaderView高度自适应

  

关键代码:

• 给header约束宽度，才能自适应高度

  - (void)didMoveToSuperview {
  	[super didMoveToSuperview];
  	if (self.superview) {
          UIView *superView = self.superview;
          self.translatesAutoresizingMaskIntoConstraints = NO;
          [NSLayoutConstraint constraintWithItem:self
                                       attribute:NSLayoutAttributeWidth
                                       relatedBy:NSLayoutRelationEqual
                                          toItem:superView
                                       attribute:NSLayoutAttributeWidth
                                      multiplier:1.0f
                                        constant:0.0f].active = YES;
  		[self updateLayout];
  	}
  }
  

• 更新tableview布局，修改完内容后需要调用

  - (void)updateLayout {
  	UITableView *tableView = (UITableView *)self.superview;
  	[tableView beginUpdates];
  	[tableView layoutIfNeeded];
  	[tableView endUpdates];
  }