用CAShapeLayer写股市K线图动画效果

用CAShapeLayer写股市K线图动画效果

说明

入市有风险，炒股需谨慎。（因项目需求，本人提供了写这种效果的源码）

效果

源码

//
//  ViewController.m
//  Path
//
//  Created by YouXianMing on 15/5/11.
//  Copyright (c) 2015年 YouXianMing. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()

@property (nonatomic, strong) NSTimer       *timer;
@property (nonatomic, strong) CAShapeLayer  *shapeLayer;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    // 生成贝塞尔曲线
    UIBezierPath* bezierPath = UIBezierPath.bezierPath;
    [bezierPath moveToPoint: CGPointMake(4.5, 2.5)];
    [bezierPath addLineToPoint: CGPointMake(32.5, 59.5)];
    [bezierPath addLineToPoint: CGPointMake(79.5, 10.5)];
    [bezierPath addLineToPoint: CGPointMake(144.5, 69.5)];
    [bezierPath addLineToPoint: CGPointMake(175.5, 15.5)];
    [bezierPath addLineToPoint: CGPointMake(211.5, 48.5)];
    [bezierPath addLineToPoint: CGPointMake(217.5, 23.5)];

    // 产生layer
    self.shapeLayer             = [CAShapeLayer layer];
    self.shapeLayer.frame       = CGRectMake(0, 0, 200, 200);
    self.shapeLayer.fillColor   = [UIColor clearColor].CGColor;
    self.shapeLayer.strokeColor = [UIColor redColor].CGColor;
    self.shapeLayer.borderWidth = 1.f;
    self.shapeLayer.path        = bezierPath.CGPath;

    // 添加layer
    [self.view.layer addSublayer:self.shapeLayer];

    // 添加定时器
    self.timer = [NSTimer scheduledTimerWithTimeInterval:1.f
                                                  target:self
                                                selector:@selector(timerEvent)
                                                userInfo:nil
                                                 repeats:YES];
}

- (void)timerEvent {
    CGFloat percent           = arc4random() % 100 / 100.f;
    self.shapeLayer.strokeEnd = percent;
    NSLog(@"%.1f%%", percent * 100);
}

@end

细节

贝塞尔曲线的坐标原点是以shapeLayer的（0，0）点计算的，注意哦，亲！