view2.backgroundColor = [UIColorredColor];
[self.viewaddSubview:view2];
UIBezierPath *maskPath = [UIBezierPathbezierPathWithRoundedRect:view2.boundsbyRoundingCorners:UIRectCornerBottomLeft |UIRectCornerBottomRight cornerRadii:CGSizeMake(10,10)];
CAShapeLayer *maskLayer = [[CAShapeLayeralloc] init];
maskLayer.frame = view2.bounds;
maskLayer.path = maskPath.CGPath;
view2.layer.mask = maskLayer;
// 其中，byRoundingCorners:UIRectCornerBottomLeft | UIRectCornerBottomRight
// 指定了需要成为圆角的角。该参数是UIRectCorner类型的，可选的值有：
UIRectCornerTopLeft
UIRectCornerTopRight
UIRectCornerBottomLeft
UIRectCornerBottomRight
UIRectCornerAllCorners
