Question

我习惯于从storyboard文件或xib文件加载ViewControllers，所以当我第一次尝试在代码中加载一个时：

UIStoryboard *storyboard = self.storyboard;

ProfileViewController *profViewController = [storyboard instantiateViewControllerWithIdentifier:@"ProfileView"];

NSLog(@"Self View Frame: %@", NSStringFromCGSize(self.view.frame.size));
NSLog(@"ProfViewCont Frame: %@", NSStringFromCGSize(profViewController.view.frame.size));

我收到以下错误：

*由于未捕获的异常'NSInvalidArgumentException'而终止应用程序，原因：'* - [NSPlaceholderMutableString initWithString：]：nil参数'

假设我的storyboard xib正确加载，我需要做些什么？这是viewDidLoad：

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    // add subviews

    self.view.backgroundColor = [UIColor clearColor];
    self.view.opaque = YES;

    [UIView beginAnimations:nil context:nil];
    [self.view setFrame:CGRectMake(0, 480, 320, 480)];

    [UIView setAnimationDuration:0.75f];
    [self.view setFrame:CGRectMake(0, 0, 320, 480)];
    [UIView commitAnimations];

    // Sort stat bars top to bottom (HP == 0):
    statBars = [statBars
                sortedArrayUsingComparator:^NSComparisonResult(id label1, id label2)
                {
                    if ([label1 frame].origin.y < [label2 frame].origin.y)
                        return NSOrderedAscending;
                    else
                        return NSOrderedDescending;
                }];

    // Sort types left to right:
    types = [types
             sortedArrayUsingComparator:^NSComparisonResult(id label1, id label2)
             {
                 if ([label1 frame].origin.x < [label2 frame].origin.x)
                     return NSOrderedAscending;
                 else
                     return NSOrderedDescending;
             }];

    [self displayInfo:currentIndex];
}

感谢您的帮助！

Answer 1

没关系，事实证明错误发生在[self displayInfo：currentIndex]中ViewDidLoad中的最后一行。我错误地认为在实例化ViewController时安全地调用了viewDidLoad。当我打电话给self.view时，很久以后就会调用它。

＆LT; _＆LT;懒惰的初始化，呵呵？

Answer 2

检查您的ProfileViewController xib，您必须将某个错误的插座连接到文件所有者

访问UIViewController时的SIGABRT

2 个答案: