ios8绘图方法小记touchesBegan&touchesMoved

//
//  MyView.swift
//  L01Test
//
//  Created by robertkun on 15/9/7.
//  Copyright (c) 2015 MAC. All rights reserved.
//

import UIKit
 class MyView: UIView { var path = CGPathCreateMutable() // Only override drawRect: if you perform custom drawing. // An empty implementation adversely affects performance during animation. override func drawRect(rect: CGRect) { // Drawing code UIColor.redColor().set() var context = UIGraphicsGetCurrentContext() CGContextSetLineWidth(context, 5) CGContextAddPath(context, path) CGContextStrokePath(context) } override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) { let p = (touches as NSSet).anyObject()?.locationInView(self) CGPathMoveToPoint(path, nil, p!.x, p!.y) } override func touchesMoved(touches: Set<NSObject>, withEvent event: UIEvent) { let p = (touches as NSSet).anyObject()?.locationInView(self) CGPathAddLineToPoint(path, nil, p!.x, p!.y) setNeedsDisplay() } func drawTwoLines(point:CGPoint, lineJoin:CGLineJoin) { let context = UIGraphicsGetCurrentContext() CGContextSetLineJoin(context, lineJoin) CGContextSetLineWidth(context, 5) CGContextMoveToPoint(context, point.x-100, point.y+50) CGContextAddLineToPoint(context, point.x, point.y) CGContextAddLineToPoint(context, point.x+100, point.y+50) CGContextStrokePath(context) } }