alertsheet 在 ipad和 iPhone上的适配

if (UI_USER_INTERFACE_IDIOM()==UIUserInterfaceIdiomPad) {//判断 是否是ipad
    UIPopoverPresentationController *popPresenter = [alertVc
                                                     popoverPresentationController];//为alertVc建立一个挂靠点
    popPresenter.sourceView = goodsCell;//挂靠点
    popPresenter.backgroundColor = [UIColor whiteColor];//避免点击时 另外的是黑框
    popPresenter.sourceRect = goodsCell.contentView.bounds;//显示的大小
    [self presentViewController:alertVc animated:YES completion:nil];
}
    else
[self presentViewController:alertVc animated:YES completion:nil];