iOS中tableviewHeader的动态高度

1.要在view中从上到下设置好各个约束

        [self.header setNeedsLayout];
            [self.header layoutIfNeeded];
            CGFloat height = [self.header systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height;
                        CGRect headerFrame = self.header.frame;
            headerFrame.size.height = height;
            self.header.frame = headerFrame;
            self.tableView.tableHeaderView = self.header;

3.自定义的header中

- (void)layoutSubviews{
    [super layoutSubviews];
    self.contenLabel.preferredMaxLayoutWidth = CGRectGetWidth(self.contenLabel.frame);
}

4.如果视图中有hidden的布局文件,在不显示的时候 要remove,避免影响自动布局