xCode 4.2错误

Question

我尝试加载另一个视图时收到此错误:

2012-02-21 20:31:38.477 App Demo[1671:f803] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSPlaceholderString initWithString:]: nil argument'

我找不到确切的错误在哪里.

有帮助吗？

更新

NSString *pn1 = player1name.text;
NSString *pn2 = player2name.text;
NSString *pn3 = player3name.text;
NSString *pn4 = player4name.text;
NSString *k = kingdomLevel.text;

Kscores *kscores = [[Kscores alloc] initWithNibName:nil bundle:nil];
kscores.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:kscores animated:YES];


[[kscores player1name] setText:[NSString stringWithString:(NSString *)pn1]];
[[kscores player2name] setText:[NSString stringWithString:(NSString *)pn2]];
[[kscores player3name] setText:[NSString stringWithString:(NSString *)pn3]];
[[kscores player4name] setText:[NSString stringWithString:(NSString *)pn4]];
[[kscores king] setText:[NSString stringWithString:(NSString *)k]];

断点停在此代码处

[[kscores player1name] setText:[NSString stringWithString:(NSString *)pn1]];

Answer 1

这样做有什么意义stringWithString:？您可以直接设置它[[kscores player1name] setText:pn1];

你得到的错误是因为pn1是零,你不能通过nil stringWithString:.