- (UIImageView *)roundedRectImageViewWithCornerRadius:(CGFloat)cornerRadius {

UIBezierPath *bezierPath = [UIBezierPath bezierPathWithRoundedRect:self.bounds cornerRadius:cornerRadius];

//UIBezierPath * bezierPath = [UIBezierPath bezierPathWithRoundedRect:backView.bounds byRoundingCorners:UIRectCornerBottomLeft|UIRectCornerTopLeft cornerRadii:CGSizeMake(width, height)];

CAShapeLayer *layer = [CAShapeLayer layer];

layer.path = bezierPath.CGPath;

self.layer.mask = layer;

return self;

}

UIButton

说明：UIButton 的背景图片，如果是复杂的图片，可以依靠 UI 切图来实现。如果是简单的纯色背景图片，可以利用代码绘制带圆角的图片。

UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];

// 设置 UIButton 的背景图片。

[button setBackgroundImage:image forState:UIControlStateNormal];

背景图片绘制方法

+ (UIImage *)pureColorImageWithSize:(CGSize)size color:(UIColor *)color cornRadius:(CGFloat)cornRadius {

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, size.width, size.height)];

view.backgroundColor = color;

view.layer.cornerRadius = cornerRadius;

// 下面方法，第一个参数表示区域大小。第二个参数表示是否是非透明的。如果需要显示半透明效果，需要传NO，否则传YES。第三个参数是屏幕密度

UIGraphicsBeginImageContextWithOptions(view.bounds.size, NO, [UIScreen mainScreen].scale);

[view.layer renderInContext:UIGraphicsGetCurrentContext()];

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return image;

}