单个角的裁剪

-(void)layoutSubviews

{

    UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, ScreenWidth-34, 1000) byRoundingCorners:UIRectCornerTopLeft | UIRectCornerTopRight cornerRadii:CGSizeMake(8, 8)];

    CAShapeLayer*maskLayer = [[CAShapeLayeralloc]init];

    maskLayer.frame=self.imagesView.bounds;

    maskLayer.path= maskPath.CGPath;

    self.imagesView.layer.mask= maskLayer;

}