Add lines on ImageView IOS (objective c) - ios

Question

I need some help to get this thing working..
Basically on button click, I have to add a line of fixed width with circle end points on the ImageView. User can add upto 5 lines. If I click on any circle (red dot) end point of line, it should allow to resize the line. Point can be dragged to any position on screen and line has to be straight. At the end, i should be able to calculate the length of each line. I just spent a lot of time on this and referring other similar answers. But so far, no luck.. Any reference code or links is greatly appreciated.
Thanks!

Answer 1

WOW, where to even start. OK, first of all, you should not be doing your drawing in the "viewDidLoad" method of your ViewController. You should make a subclass of UIView (let's call it DrawView) and do all your drawing within the "drawRect" method. And within DrawView, you can then intercept touches.
So to get a little more precise:
create subclass of UIView called DrawView
Move your drawing into the drawRect method
Within DrawView, over-ride the various "touchesXXXX" methods (of UIResponder) to detect and respond to touches and figure out what shape has been touched
Within the storyboard, drag a UIView object onto your ViewController and make sure it's class is set to "DrawView".
This is for starters. Haven't even talked about how to record/store your various points and shapes.

Answer 2

To Draw line on image view the following code work for me even in view did load.
first int image view
second write following code
//line 1
CAShapeLayer *shapeLayerOne = [CAShapeLayer layer];
shapeLayerOne.path = [LineOne CGPath];
shapeLayerOne.strokeColor = [[UIColor blueColor] CGColor];
shapeLayerOne.lineWidth = 1.0;
shapeLayerOne.fillColor = [[UIColor clearColor] CGColor];
//line 2
CAShapeLayer *shapeLayerTwo = [CAShapeLayer layer];
shapeLayerTwo.path = [LineTwo CGPath];
shapeLayerTwo.strokeColor = [[UIColor blueColor] CGColor];
shapeLayerTwo.lineWidth = 1.0;
shapeLayerTwo.fillColor = [[UIColor clearColor] CGColor];
//line 3
CAShapeLayer *shapeLayerThree = [CAShapeLayer layer];
shapeLayerThree.path = [LineThree CGPath];
shapeLayerThree.strokeColor = [[UIColor blueColor] CGColor];
shapeLayerThree.lineWidth = 1.0;
shapeLayerThree.fillColor = [[UIColor clearColor] CGColor];
//line 4
CAShapeLayer *shapeLayerFour = [CAShapeLayer layer];
shapeLayerFour.path = [LineFour CGPath];
shapeLayerFour.strokeColor = [[UIColor blueColor] CGColor];
shapeLayerFour.lineWidth = 1.0;
shapeLayerFour.fillColor = [[UIColor clearColor] CGColor];
[self.view.layer addSublayer:shapeLayerOne];
[self.view.layer addSublayer:shapeLayerTwo];
[self.view.layer addSublayer:shapeLayerThree];
[self.view.layer addSublayer:shapeLayerFour];
your output is blue line