UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:btn.bounds byRoundingCorners:UIRectCornerBottomRight cornerRadii:CGSizeMake(10, 10)];
CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
maskLayer.frame = btn.bounds;
maskLayer.path = maskPath.CGPath;
btn.layer.mask = maskLayer;
图片发自简书App
