Custom UITableView Header set background colour fail - ios

Question

I created a custom UITableViewHeaderFooterView, and the tableview's background colour is white.
self.contentView.backgroundColor = UIColor.clearColor()
However, the section header's background always appears like gray. How can I remove the gray background??
Since I have override the drawRect func of the UITableView, so I want something to appear behind the header view.
I have tried the following:
a) Change the UITableView style to Grouped, the problem goes, but the header cannot glued on top of the table.
b) Use section header title instead of header view
func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String?
the header's background is transparent, but I have multiple labels.
Can anyone help me to figure this out?
Thanks to #Omkar, the correct way is set
cell.layer.backgroundColor = UIColor.clearColor().CGColor

Answer 1

You need to set the background colour of the content view to clear color and at the same time you also need to set the background color of the tableView cell to clear color. Place this in your viewForHeaderInSection method. You will then be able to see the color set to the tableView.
YourCell.contentView.backgroundColor = UIColor.clearColor()
YourCell.backgroundColor = UIColor.clearColor()
Please find the attached image for my code and also the table view whose style is plain style in storyboard. And i have also added the image of how it looks after running
Thanks

Answer 2

This is my ViewController code, the only difference is I use headerfootview subclass. I set the tableview's background to blue, and if i pull down a little bit, you will see there looks like a mask on header.
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
tableView.dataSource = self
tableView.delegate = self
tableView.registerClass(UITableViewHeaderFooterView.self, forHeaderFooterViewReuseIdentifier: "HeaderCell")
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 4
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 10
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("CustomCell", forIndexPath: indexPath)
cell.textLabel?.text = "\(indexPath.row)"
return cell
}
func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let cell = tableView.dequeueReusableHeaderFooterViewWithIdentifier("HeaderCell") as UITableViewHeaderFooterView!
cell!.textLabel?.text = "Header"
cell!.contentView.backgroundColor = UIColor.clearColor()
cell.backgroundColor = UIColor.clearColor()
return cell
}
}