tableView：numberOfRowsInSection：是确定将显示多少行的方法，因此第一步将是更改。在视图控制器中还需要一个属性来跟踪应该显示多少行。类似这样：

tableView:numberOfRowsInSection: is the method that determines how many rows will be shown, so the first step will be to change that. You also need a property in your view controller to keep track of how many rows should be visible. Something like this:

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return self.numberOfRowsVisible;
}

当点击更多按钮时，必须增加该数字并重新加载tableView数据。

And when the more button is clicked, you have to increase that number and reload the tableView data.

-(void)moreButtonClickAction {
    if (self.numberOfRowsVisible < self.maxNumberOfRows) 
        self.numberOfRowsVisible = MIN(self.numberOfRowsVisible + 10, self.maxRows);
    [self.tableView reloadData];
}