How do I remove all subviews in Rubymotion? - ios

Question

Basically, I have a quiz app where I add have questions, then switch to a different screen to show an expanded version of the correct answer after it is chosen. I've tried adding button and labels, but when I do this, I eventually end up with buttons and labels 'ghosting' on the screen, after I went them gone. How can I remove all subviews, so that each button and label I add from within a method appears on a fresh screen?
class MyApplicationController < UIViewController
def loadView
self.view = UIImageView.alloc.init
end
def viewDidLoad
super
view.userInteractionEnabled=true
#question_index=0
#answerChoices = []
#questionChoices=["What is best in life?",...]
makeQuestion
end
def makeQuestion
left =20
top=100
label = UILabel.new
label.text =#questionChoices[#question_index]
label.textAlignment = UITextAlignmentCenter
label.textColor = UIColor.redColor
label.frame = [[20,20], [view.frame.size.width-40, 40]]
label.lineBreakMode = UILineBreakModeWordWrap
label.numberOfLines = 0
label.sizeToFit
view.image = UIImage.imageNamed('background.jpg')
view.addSubview(label)
4.times do |i|
#button = UIButton.buttonWithType(UIButtonTypeRoundedRect)
#button.setTitle(#answerChoices[i][#question_index], forState:UIControlStateNormal)
#button.frame = [[left, top], [view.frame.size.width - left * 2, 40]]
#button.addTarget(self, action:'actionTapped:', forControlEvents:UIControlEventTouchUpInside)
#button.tag=i
top+=45
view.addSubview(#button)
end
end
def makeAnswer
#button.removeFromSuperview
#button.removeFromSuperview
#button.removeFromSuperview
#button.removeFromSuperview
view.image = UIImage.imageNamed('back.jpg')
label = UILabel.new
label.text =#rightArray[#question_index]
label.textAlignment = UITextAlignmentCenter
label.textColor = UIColor.blackColor
label.frame = [[20,20], [view.frame.size.width-40, 40]]
label.lineBreakMode = UILineBreakModeWordWrap
label.numberOfLines = 0
label.sizeToFit
view.addSubview(label)
#button = UIButton.buttonWithType(UIButtonTypeRoundedRect)
#button.setTitle("More questions", forState:UIControlStateNormal)
#button.tag=1
#button.addTarget(self, action:'makeQuestion', forControlEvents:UIControlEventTouchUpInside)
#button.frame = [[20, 100], [view.frame.size.width - 20 * 2, 40]]
view.addSubview(#button)
end
end

Answer 1

You need an array of buttons. In your 4.times loop, you are overwriting the instance variable #button four times. Instead, make #button an array of buttons, and assign a different button to each index.
If you have a variable myView and want to remove all of its subviews, I believe this will work:
myView.subviews.each {|sv| sv.removeFromSuperview}