////  DrawView.m//  06-粒子效果////  Created by xiaomage on 15/6/24.//  Copyright (c) 2015年 xiaomage. All rights reserved.//#import "DrawView.h"@interface DrawView ()@property (nonatomic, strong) UIBezierPath *path;@property (nonatomic, weak) CALayer *dotLayer;@property (nonatomic, weak) CAReplicatorLayer *repL;@end@implementation DrawView#pragma mark - 懒加载点层- (CALayer *)dotLayer{    if (_dotLayer == nil) {        // 创建图层        CALayer *layer = [CALayer layer];                CGFloat wh = 10;        layer.frame = CGRectMake(0, -1000, wh, wh);                layer.cornerRadius = wh / 2;                layer.backgroundColor = [UIColor blueColor].CGColor;        [_repL addSublayer:layer];                _dotLayer = layer;    }    return _dotLayer;}- (UIBezierPath *)path{    if (_path == nil) {        _path = [UIBezierPath bezierPath];    }        return _path;}#pragma mark - 开始点击调用- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{        // 获取touch对象    UITouch *touch = [touches anyObject];        // 获取当前触摸点    CGPoint curP = [touch locationInView:self];            // 设置起点    [self.path moveToPoint:curP];            }static int _instansCount = 0;- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{    // 获取touch对象    UITouch *touch = [touches anyObject];        // 获取当前触摸点    CGPoint curP = [touch locationInView:self];    // 添加线到某个点    [_path addLineToPoint:curP];        // 重绘    [self setNeedsDisplay];        _instansCount ++;    }// Only override drawRect: if you perform custom drawing.// An empty implementation adversely affects performance during animation.- (void)drawRect:(CGRect)rect {    // Drawing code        [_path stroke];}#pragma mark - 开始动画- (void)startAnim{    // 创建帧动画    CAKeyframeAnimation *anim = [CAKeyframeAnimation animation];        anim.keyPath = @"position";        anim.path = _path.CGPath;        anim.duration = 3;        anim.repeatCount = MAXFLOAT;        [self.dotLayer addAnimation:anim forKey:nil];        // 注意:如果复制的子层有动画，先添加动画，在复制    // 复制子层    _repL.instanceCount = _instansCount;        // 延迟图层动画    _repL.instanceDelay = 0.2;    }#pragma mark - 加载完xib调用，创建复制层- (void)awakeFromNib{    // 创建复制层    CAReplicatorLayer *repL = [CAReplicatorLayer layer];        repL.frame = self.bounds;        [self.layer addSublayer:repL];      _repL = repL;}#pragma mark - 重绘- (void)reDraw{    // 清空绘图信息    _path = nil;    [self setNeedsDisplay];        // 把图层移除父控件，复制层也会移除。     [_dotLayer removeFromSuperlayer];    _dotLayer = nil;    // 清空子层总数    _instansCount = 0;    }@end

// 点击开始动画- (IBAction)startAnim:(id)sender {        DrawView *view = (DrawView *)self.view;    [view startAnim];    }// 重置按钮- (IBAction)reDraw:(id)sender {        DrawView *view = (DrawView *)self.view;    [view reDraw];}