title: UITableView section header overlap the customized headerView?
body: <p>I have trying to resize the view or add constrains but not work.
  <a href="https://i.stack.imgur.com/Ra5wP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Ra5wP.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/RzyWp.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RzyWp.png" alt="enter image description here"></a></p>
  
  <p>This is the code not work:</p>
  
  <pre><code>- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
  {
      if (section == 0) {
          return 100;
      }
      return 0;
  }
  
  -(UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
  {
      //self.mainViewTableView.tableHeaderView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 0, 0.1)];
      if (section == 0) {
          UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 50, tableView.frame.size.width, 100)];
          //[view setBackgroundColor:[UIColor colorWithRed:240/255.0 green:240/255.0 blue:240/255.0 alpha:1]];
          [view setBackgroundColor:[UIColor redColor]];
          [self.mainViewTableView setTableHeaderView:view];
          return view;
      }
      else{
          return nil;
      }
  
  }
  </code></pre>
  
  <p>But when I try this, it works find.(This is not I want, I want add header view in storyboard but not add it programmatically.)</p>
  
  <pre><code>UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, view.frame.size.width, 300)];
  //[view setBackgroundColor:[UIColor colorWithRed:240/255.0 green:240/255.0 blue:240/255.0 alpha:1]];
  [view setBackgroundColor:[UIColor redColor]];
  [self.mainViewTableView setTableHeaderView:view];
  </code></pre>