设置ViewController 数据源无法改变view

病情描述：

1. viewController创建的时候勾选了xib，然后在显示的时候调用了如下语句：

   MTDetailDealViewController *detailController = [[MTDetailDealViewController alloc]init];
   detailController.deal = [self.deals objectAtIndex:indexPath.item];
   [self presentViewController:detailController animated:YES completion:nil];

2. 发现界面根本没有按照数据源发生改变

病情原因：

1. 将viewController的几个生命周期关键方法进行打印，发现：

   2016-04-20 01:26:44.369 MTHD[6384:380078] -MTDetailDealViewController initWithNibName:bundle::
   2016-04-20 01:26:44.370 MTHD[6384:380078] -MTDetailDealViewController init:
   2016-04-20 01:26:44.370 MTHD[6384:380078] -MTDetailDealViewController setDeal::
   2016-04-20 01:26:45.421 MTHD[6384:380078] -MTDetailDealViewController loadView:

2. 联想起上篇知识总结
   iOS viewController 和 view 的创建消失生命周期总结的第4点

改正如下：

MTDetailDealViewController *detailController = [[MTDetailDealViewController alloc]init];
//必须得先调用view,否则下面的句子将会无效
[detailController loadView];
detailController.deal = [self.deals objectAtIndex:indexPath.item];
[self presentViewController:detailController animated:YES completion:nil];

再次打印发现：

2016-04-20 01:29:28.728 MTHD[6452:382311] -MTDetailDealViewController initWithNibName:bundle::
2016-04-20 01:29:28.729 MTHD[6452:382311] -MTDetailDealViewController init:
2016-04-20 01:29:28.983 MTHD[6452:382311] -MTDetailDealViewController loadView:
2016-04-20 01:29:28.983 MTHD[6452:382311] -MTDetailDealViewController setDeal::