iOS 扇形

先上效果图

• PieView.h

@interface PieView : UIView

-(instancetype)initWithCenter:(CGPoint)center radius:(CGFloat)radius bgColor:(UIColor *)bgColor andstartAngle:(CGFloat)startAngle andendAngle:(CGFloat)endAngle;

@end

-(instancetype)initWithCenter:(CGPoint)center radius:(CGFloat)radius bgColor:(UIColor *)bgColor andstartAngle:(CGFloat)startAngle andendAngle:(CGFloat)endAngle {
    
    self = [super init];
    if (self) {
        //设置self的frame和center
        self.backgroundColor = bgColor;
        self.frame = CGRectMake(0, 0, radius * 2, radius * 2);
        self.center = center;
        
    
        //特别注意：贝塞尔曲线的radius必须为self高度的四分之一，CAShapeLayer的线宽必须为self高度的二分之一
        UIBezierPath *path = [UIBezierPath bezierPathWithArcCenter:CGPointMake(radius, radius) radius:radius / 2 startAngle:startAngle endAngle:endAngle clockwise:YES];
        
        CAShapeLayer *maskLayer = [CAShapeLayer layer];
        maskLayer.path = path.CGPath;
        maskLayer.fillColor = [UIColor clearColor].CGColor;
        maskLayer.strokeColor = bgColor.CGColor;
        maskLayer.lineWidth = radius; //等于半径的2倍，以圆的边缘为中心，向圆内部伸展一个半径，向外伸展一个半径，所以看上去以为圆的半径是self高度的一半。
        self.layer.mask = maskLayer;
    }
    
    return self;
}

• 实现

CGPoint point = CGPointMake(150, 150);
    PieView *redView = [[PieView alloc] initWithCenter:point radius:50 bgColor:[UIColor redColor] andstartAngle:-M_PI/2 andendAngle:0.0];
    [self.view addSubview:redView];
    
    PieView *blueView = [[PieView alloc] initWithCenter:point radius:70 bgColor:[UIColor blueColor] andstartAngle:0.0f andendAngle:M_PI*3/2];
    [self.view addSubview:blueView];