YinFeng Piao

Install pods and add objective c bridging header.

Yes

 File replace #import "DPRollingEqualizerView.h" @implementation DPRollingEqualizerView #pragma mark - Drawing - (void)drawRect:(CGRect)rect { CGContextRef ctx = UIGraphicsGetCurrentContext(); CGContextSaveGState(ctx); CGRect frame = self.bounds; [(UIColor *)self.backgroundColor set]; UIRectFill(frame); CGFloat columnWidth =...