在viewdidload方法中切换视图控制器

Question

我正在开发一个 iPhone 应用程序，因为我想通过检查用户默认值来切换视图控制器。所以我做了以下操作：

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

if ([defaults objectForKey:@"keyString"] != nil) {
    nextViewController *redirectView = [[nextViewController alloc] initWithNibName:@"nextViewController" bundle:[NSBundle mainBundle]];
self.nextView = redirectView;
[self presentModalViewController:self.nextView animated:YES];
} else {
[defaults setObject:@"newValue" forKey:@"keyString"];
}

它不起作用..这是正确的方法吗？？？如果没有的话谁能告诉我该怎么做..

Answer 1

不要将redirectView分配给self.nextView。直接这样传过去

[self presentModalViewController:redirectView animated:YES];

Answer 2

添加该行

[self.view addSubview:nextView]; 

而不是

[self presentModalViewController:self.nextView animated:YES];

Answer 3

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

if ([defaults objectForKey:@"keyString"] != nil) 
{ nextViewController *redirectView = [[nextViewController alloc]init]; 
[self presentModalViewController:redirectView animated:YES]; 
redirectView=nil;
 } 
else { 
[defaults setObject:@"newValue" forKey:@"keyString"]; 

}