Question

我的笔尖名称中有一个拼写错误，当我推送到导航控制器时，它在代码中爆炸了。它没有花太长时间来搞清楚，但我认为最好先断言好形象，以便更容易弄明白。问题是它不是零，它只是不能正确地从笔尖形成自己。在initWithNib之后是否有更好的断言或捕获来检查代码中的问题？

//
// typo in nib name - I want to catch before it blows up inside of pushViewController to narrow the problem
//
ENPurchaseDetailView *purchaseView = [[ENPurchaseDetailView alloc] 
    initWithNibName:@"XibWithTypoInIt" bundle:nil];
assert(purchaseView != nil);  // does not catch - it's not nil - just not well formed

// other code ...

// blows up with sigabort inside of pushViewController
[[self navigationController] pushViewController:purchaseView animated:YES];

Answer 1

创建一个基础UIViewController类，您可以从中继承所有其他VC。然后，您可以在基类中执行许多有用的断言，而不必在整个代码中分散它们。这是我使用的一个

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
   self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]

// never do this stuff in production code
#ifdef DEBUG
    // make sure you didn't fat finger Xib name
    if (nibNameOrNil)
    {
        NSString *path = [[NSBundle mainBundle] pathForResource:nibNameOrNil ofType:@"nib"];
        NSAssert(path, @"Nib %@ does not exist", nibNameOrNil);
    }

    // make sure there's no problems with the Xib
    UINib *nib = [UINib nibWithNibName:nibNameOrNil bundle:nibBundleOrNil ];
    NSArray *instantiatedObjects = [nib instantiateWithOwner:nil options:nil];
    NSAssert(instantiatedObjects && [instantiatedObjects count] > 0, @"Not well formed Xib");
#endif       return self;
}

之前检测有问题的XIB视图

1 个答案: