简单实现扇形图表

Demo地址

主要代码

1、遍历所有扇形的比例,计算出每个扇形区域的开始和结束角度,然后绘制FanShapeLayer

int max = 0;
    for (NSNumber * obj in self.angles) {
        max += [obj intValue];
    }
    
    CGFloat startAngle = self.startAngle;// 起点 0 代表x轴正方向
    
    for (int i = 0; i < self.angles.count; i ++) {
        NSNumber * obj = [self.angles objectAtIndex:i];
        
        CGFloat rate = [obj intValue];
        CGFloat angle = rate / max * M_PI * 2.0;
        
        // 计算绘制角度-终点 绘制的角度 绘制的方向是逆时针的所以是减
        CGFloat endAngle = startAngle - angle;
        
        // 设置颜色
        UIColor * color = randomColor;
        
        // 创建FanShapeLayer
        FanShapeLayer * layer = [[FanShapeLayer alloc]init];
        layer.fillColor = color.CGColor;
        layer.name = [NSString stringWithFormat:@"图层 = %d",i];
        layer.startAngle = startAngle;
        layer.endAngle = endAngle;
        layer.radius = self.radius;
        layer.centerPoint = self.chartPoint;
        // 绘制路径(先设置参数)
        [layer drawPath];
        [self.layer addSublayer:layer];
        [self.fansArray addObject:layer];
        
        // 计算下一次绘制起点
        startAngle -= angle;
    }

2、在设置FanShapeLayer的参数后,先绘制CGMutablePathRef即一个封闭的扇形,然后把CGMutablePathRef赋给FanShapeLayer

CGMutablePathRef path = CGPathCreateMutable();
    CGAffineTransform transform = CGAffineTransformMakeTranslation(1, 1);
    CGPathMoveToPoint(path, &transform, self.centerPoint.x, self.centerPoint.y);
    CGPathAddArc(path, &transform, self.centerPoint.x, self.centerPoint.y, radius, self.startAngle, self.endAngle, YES);
    CGPathCloseSubpath(path);

3、主要是点击放大,CALyer是不响应点击事件的,这里是通过获得触摸对象的点是否在layer区域内实现的。

网上查到可以通过下面方法获得点击的图层,但这里得到的是nil,不知道为什么。
CALayer * layer = [self.layer hitTest:point];

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
    // 获取点击的中心点
    UITouch * touch = [touches anyObject];
    CGPoint point = [touch locationInView:self];
    // 获取点击区域 是否包含的CAShapeLayer
    FanShapeLayer * layer = [self touchLayer:point];
    if (layer) {
        NSLog(@"%@", layer.name);
        // 设置选中的为未选中
        NSPredicate * predicate = [NSPredicate predicateWithFormat:@"isSelected = YES"];
        NSArray * selectArray = [self.fansArray filteredArrayUsingPredicate:predicate];
        [selectArray makeObjectsPerformSelector:@selector(setIsSelected:) withObject:@NO];
        if ([selectArray containsObject:layer]) {
            return ;
        }
        // 添加动画
        layer.isSelected = YES;
    }
}

- (FanShapeLayer *)touchLayer:(CGPoint)point{
    // 获取点击的区域layer
    for (FanShapeLayer * layer in self.fansArray) {
        // 获取inPoint，在layer中的坐标
        CGPoint inPoint = [layer convertPoint:point fromLayer:self.layer];
        
        if (CGPathContainsPoint(layer.path, 0, inPoint, YES)) {
            return layer;
        }
    }
    return nil;
}

4、最后在点击的时候添加缩放动画

  // 添加动画
        CABasicAnimation *animation = [CABasicAnimation animation];
        // keyPath内容是对象的哪个属性需要动画
        animation.keyPath = @"path";
        // 设置代理
        animation.delegate = self;
        // 所改变属性的结束时的值
        animation.toValue = (__bridge id _Nullable)(self.endPath);
        // 动画时长
        animation.duration = 0.25;
        // 结束后不移除
        animation.removedOnCompletion = NO;
        animation.fillMode = kCAFillModeForwards;
        // 添加动画
        [self addAnimation:animation forKey:nil];