Switching view controller in viewdidload method

I am developing one iphone application in that i want to switch view controller by checking userdefaults. so i did the following:

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

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

Its not working.. Is this the right way??? If not can anyone tell me how to do that..

Dont assign redirectView to self.nextView. Pass it directly like this

[self presentModalViewController:redirectView animated:YES];

Add the line

[self.view addSubview:nextView]; 

instead of

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

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"]; 

}