项目中用到了自己画的虚线，记录一下：

- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {
        
        
        // 画虚线
        
        CAShapeLayer *shapeLayer = [CAShapeLayer layer];
        [shapeLayer setFillColor:[[UIColor clearColor] CGColor]];
        
        // 设置虚线颜色为blackColor
        [shapeLayer setStrokeColor:[[UIColor colorWithHex:@"#dcd2de"] CGColor]];
        [shapeLayer setStrokeColor:[[UIColor colorWithRed:223/255.0 green:223/255.0 blue:223/255.0 alpha:1.0f] CGColor]];
        
        // 3.0f设置虚线的宽度
        [shapeLayer setLineWidth:1.0f];
        [shapeLayer setLineJoin:kCALineJoinRound];
        
        // 8=线的宽度 3=每条线的间距
        [shapeLayer setLineDashPattern:
         [NSArray arrayWithObjects:[NSNumber numberWithInt:8],
          [NSNumber numberWithInt:6],nil]];
        
        // Setup the path
        CGMutablePathRef path = CGPathCreateMutable();
        CGPathMoveToPoint(path, NULL, 25, 15);
        CGPathAddLineToPoint(path, NULL, frame.size.width-25,15);
        
        [shapeLayer setPath:path];
        CGPathRelease(path);
        
        // 可以把self改成任何你想要的UIView
        [[self layer] addSublayer:shapeLayer];
        
    }
    return self;
}