CAShapeLayer绘图 及其 简单封装

什么是CAShapeLayer

CAShapeLayer是一个通过矢量图形而不是bitmap来绘制的图层CALayer的子类。你指定诸如颜色和线宽等属性,用CGPath来定义想要绘制的图形,最后CAShapeLayer就自动渲染出来了。
当然,你也可以用Core Graphics直接向原始的CALyer的内容中绘制一个路径,相比直下,使用CAShapeLayer有以下一些优点:

  1. 渲染快速CAShapeLayer使用了硬件加速,绘制同一图形会比用Core Graphics快很多。
  2. 高效使用内存。一个CAShapeLayer不需要像普通CALayer一样创建一个寄宿图形,所以无论有多大,都不会占用太多的内存。
  3. 不会被图层边界剪裁掉。一个CAShapeLayer可以在边界之外绘制。你的图层路径不会像在使用Core Graphics的普通CALayer一样被剪裁掉。
  4. 不会出现像素化。当你给CAShapeLayer做3D变换时,它不像一个有寄宿图的普通图层一样变得像素化。

简单实用

1 . 绘制原型进度条


进度条
//创建CAShapeLayer
    CAShapeLayer *shapeLayer = [CAShapeLayer layer];

//设置动画开始点和结束点(不需要动画可忽略)
    shapeLayer.strokeEnd = 0.7f;
    shapeLayer.strokeStart = 0.1f;

//利用oc的 UIBezierPath 方法创建路径
    UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:_demoView.bounds];

//赋值路径给layer
    shapeLayer.path = path.CGPath;

//个性化设置
    shapeLayer.fillColor = [UIColor clearColor].CGColor;
    shapeLayer.lineWidth = 2.0f;
    shapeLayer.strokeColor = [UIColor redColor].CGColor;

//添加shapeLayer到view的layer
    [_demoView.layer addSublayer:shapeLayer];

//添加动画
    CABasicAnimation *pathAnima = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
    pathAnima.duration = 3.0f;
    pathAnima.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    pathAnima.fromValue = @(0.0);
    pathAnima.toValue = @(1.0);
    pathAnima.fillMode = kCAFillModeForwards;
    pathAnima.removedOnCompletion = NO;
    [shapeLayer addAnimation:pathAnima forKey:@"strokeEndAnimation"];

2 . 绘制折线图

折线图
    //坐标点数组
    
    NSArray *pointArray = @[[NSValue valueWithCGPoint:CGPointMake(110, 130)],
                            [NSValue valueWithCGPoint:CGPointMake(140, 220)],
                            [NSValue valueWithCGPoint:CGPointMake(170, 150)],
                            [NSValue valueWithCGPoint:CGPointMake(230, 110)],
                            [NSValue valueWithCGPoint:CGPointMake(270, 180)]];
    
    
    
    //创建
    CAShapeLayer *shapeLayer = [CAShapeLayer layer];
    
    shapeLayer.strokeEnd = 0.7f;
    shapeLayer.strokeStart = 0.1f;
    
    //创建路径
    UIBezierPath *path = [UIBezierPath bezierPath];
    
    [path moveToPoint:[pointArray.firstObject CGPointValue]];
    
    for (int i = 0; i < pointArray.count; i++)
    {
        
        if (i) [path addLineToPoint:[pointArray[i] CGPointValue]];
    }
    
    //赋值路径
    shapeLayer.path = path.CGPath;
    
    shapeLayer.fillColor = [UIColor clearColor].CGColor;
    shapeLayer.lineWidth = 2.0f;
    shapeLayer.strokeColor = [UIColor redColor].CGColor;
    
    [self.view.layer addSublayer:shapeLayer];
    
    //添加动画
    CABasicAnimation *pathAnima = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
    pathAnima.duration = 3.0f;
    pathAnima.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    pathAnima.fromValue = @(0.0);
    pathAnima.toValue = @(1.0);
    pathAnima.fillMode = kCAFillModeForwards;
    pathAnima.removedOnCompletion = NO;
    [shapeLayer addAnimation:pathAnima forKey:@"strokeEndAnimation"];

基于项目作的封装

因为项目有用到很多需要绘制图形的地方,比如分时线、k线、饼状图等等。于是对CAShapeLayer进行了简单的封装,便于方便的绘图。

工具类的声明和实现

声明

//
//  UPShapeLayer.h
//  UPBaseUI
//
//  Created by Jimmy on 17/4/24.
//  Copyright © 2017年 UpChina. All rights reserved.
//

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

#define UPShapeLayerDefaultDuration 0.35

/**
 基于CALayer的绘图工具
 */
@interface UPShapeLayer : CAShapeLayer

@property (nonatomic, strong) UIBezierPath *bezierPath;

@property (nonatomic, assign) BOOL animate;

+ (instancetype)shapeLayer;

/**
 画折线的方法

 @param pointArray 折线位置数组
 @param strokeColor 折线颜色
 @param lineWidth 线宽
 */
- (void)drawLineWithPointArray:(NSArray *)pointArray strokeColor:(UIColor *)strokeColor lineWidth:(CGFloat)lineWidth;


/**
 画直方图的方法

 @param pointsArray 直方图坐标数组(每一条直方图包含起始点和结束点) NSArray<NSArray<startPoint,endPoint> *> *)
 @param strokeColor 直方图颜色
 @param lineWidth 线宽
 */
- (void)drawHistogramWithPointsArray:(NSArray<NSArray *> *)pointsArray strokeColor:(UIColor *)strokeColor lineWidth:(CGFloat)lineWidth;

/**
 画圆的方法

 @param center 圆中心点
 @param radius 圆半径
 @param startAngle 起始角度
 @param endAngle 结束角度
 @param clockwise 绘图方向
 @param strokeColor 笔划颜色
 @param lineWidth 线宽
 */
- (void)drawArcWithArcCenter:(CGPoint)center radius:(CGFloat)radius startAngle:(CGFloat)startAngle endAngle:(CGFloat)endAngle clockwise:(BOOL)clockwise strokeColor:(UIColor *)strokeColor lineWidth:(CGFloat)lineWidth;

@end

实现

//
//  UPShapeLayer.m
//  UPBaseUI
//
//  Created by Jimmy on 17/4/24.
//  Copyright © 2017年 UpChina. All rights reserved.
//

#import "UPShapeLayer.h"

@implementation UPShapeLayer


+ (instancetype)shapeLayer
{
    return [[self alloc] init];
}

- (instancetype)init
{
    if (self = [super init])
    {
        self.fillColor = nil;
        
        [self setupViews];
    }
    return self;
}

/**
 初始化
 */
- (void)setupViews
{
}

- (void)drawLineWithPointArray:(NSArray *)pointArray strokeColor:(UIColor *)strokeColor lineWidth:(CGFloat)lineWidth
{
    UIBezierPath *path = [UIBezierPath bezierPath];
    
    CGPoint firstPoint = [pointArray.firstObject CGPointValue];
    
    [path moveToPoint:firstPoint];
    
    for (int i = 1; i < pointArray.count; i++)
    {
        CGPoint point = [pointArray[i] CGPointValue];
        
        [path addLineToPoint:point];
    }
    
    self.strokeColor = strokeColor.CGColor;
    self.lineWidth = lineWidth;
    self.bezierPath = path;
    
}

- (void)drawHistogramWithPointsArray:(NSArray<NSArray *> *)pointsArray strokeColor:(UIColor *)strokeColor lineWidth:(CGFloat)lineWidth
{
    self.strokeColor = strokeColor.CGColor;
    self.lineWidth = lineWidth;
    
    UIBezierPath *path = [UIBezierPath bezierPath];
    
    [pointsArray enumerateObjectsUsingBlock:^(NSArray * points, NSUInteger idx, BOOL * _Nonnull stop) {
        
        [path moveToPoint:[points.firstObject CGPointValue]];
        [path addLineToPoint:[points.lastObject CGPointValue]];
        
    }];
    
    self.bezierPath = path;

    
}

- (void)drawArcWithArcCenter:(CGPoint)center radius:(CGFloat)radius startAngle:(CGFloat)startAngle endAngle:(CGFloat)endAngle clockwise:(BOOL)clockwise strokeColor:(UIColor *)strokeColor lineWidth:(CGFloat)lineWidth
{
    UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:center radius:radius startAngle:startAngle endAngle:endAngle clockwise:clockwise];
    
    self.strokeColor = strokeColor.CGColor;
    self.lineWidth = lineWidth;
    self.bezierPath = path;

}

#pragma mark - SETTER & GETTER
- (void)setBezierPath:(UIBezierPath *)bezierPath
{
    _bezierPath = bezierPath;
    
    self.path = bezierPath.CGPath;
}

- (void)setAnimate:(BOOL)animate
{
    _animate = animate;
    
    if (animate = YES)
    {
        // 创建Animation
        CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
        animation.fromValue = @(0.0);
        animation.toValue = @(1.0);
        //
        animation.duration = UPShapeLayerDefaultDuration;
        
        
        // 设置layer的animation
        [self addAnimation:animation forKey:@"ani"];
        self.strokeEnd = 1;
    }
    else
    {
        [self removeAllAnimations];
    }
}

@end

使用
//
//  ViewController.m
//  test
//
//  Created by Jimmy on 17/4/27.
//  Copyright © 2017年 upChina. All rights reserved.
//

#import "ViewController.h"
#import "UPShapeLayer.h"

@interface ViewController ()

@property (nonatomic, strong) UPShapeLayer *shapeLayer;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
}



- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    
    //坐标点数组
    
    NSArray *pointArray = @[[NSValue valueWithCGPoint:CGPointMake(110, 130)],
                            [NSValue valueWithCGPoint:CGPointMake(140, 220)],
                            [NSValue valueWithCGPoint:CGPointMake(170, 150)],
                            [NSValue valueWithCGPoint:CGPointMake(230, 110)],
                            [NSValue valueWithCGPoint:CGPointMake(270, 180)]];
    
    
    [self.shapeLayer drawLineWithPointArray:pointArray strokeColor:[UIColor grayColor] lineWidth:2];
    
    
}

- (UPShapeLayer *)shapeLayer
{
    if (!_shapeLayer)
    {
        _shapeLayer = [UPShapeLayer shapeLayer];
        
        //只需要一次动画的话在初始化方法设置
        _shapeLayer.animate = YES;
        
        [self.view.layer addSublayer:_shapeLayer];
    }
    return _shapeLayer;
}

@end

这样就能用简单的接口实现最高效的绘图,目前这个工具类还在继续完善,希望大家有需求都可以提出来,大家共同进步。

推荐阅读更多精彩内容