//iOS9之前的 说明已经收藏过了
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:@"已经收藏啦" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"确定", nil];
[alert show];
//ios9之后的提示框
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"" message:@"" preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *action1 = [UIAlertAction actionWithTitle:@"" style:UIAlertActionStyleCancel handler:nil];
[alertController addAction:action1];
[self presentViewController:alertController animated:YES completion:nil];
