The app delegate must implement the window property if it wants to use a main storyboard file

Question

I'm programmatically implement a list view controller. When I try to run the project, I got error:

2012-11-07 22:46:34.719 myTableViewControl[12021:c07] The app delegate must implement the         window property if it wants to use a main storyboard file.
2012-11-07 22:46:34.722 myTableViewControl[12021:c07] -[AppDelegate setWindow:]:     unrecognized selector sent to instance 0x7674e70
2012-11-07 22:46:34.723 myTableViewControl[12021:c07] *** Terminating app due to uncaught     exception 'NSInvalidArgumentException', reason: '-[AppDelegate setWindow:]: unrecognized     selector sent to instance 0x7674e70'
*** First throw call stack:
(0x1c8e012 0x10cbe7e 0x1d194bd 0x10df7ea 0x1c7dcf9 0x1c7d94e 0x1d60 0x107b7 0x10da7     0x11fab 0x23315 0x2424b 0x15cf8 0x1be9df9 0x1be9ad0 0x1c03bf5 0x1c03962 0x1c34bb6 0x1c33f44     0x1c33e1b 0x117da 0x1365c 0x1bd2 0x1b05)
libc++abi.dylib: terminate called throwing an exception
(lldb) 

When I run the code, it hang on the main.m and shows that

"thread1: signal SIGABRT"

@autoreleasepool {return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));

my code is as following: AppDelegate.h

//
//  AppDelegate.h
//  myTableViewControl
//
//  Created by Max on 12-11-5.
//  Copyright (c) 2012年 Max. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UINavigationController *navigationController;


@end

AppDelegate.m

//
//  AppDelegate.m
//  myTableViewControl
//
//  Created by Max on 12-11-5.
//  Copyright (c) 2012年 Max. All rights reserved.
//

    #import "AppDelegate.h"
    #import "firstViewController.h"


@implementation AppDelegate
@synthesize navigationController;


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:    (NSDictionary *)launchOptions
{
    // create the base window
    UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    window.backgroundColor = [UIColor greenColor];
    self.window = window;

    [window release];

    // this is the home page from the user's perspective

    FirstViewController *fvc = [[FirstViewController alloc] init];

    UINavigationController *nc = [[UINavigationController alloc]initWithRootViewController:fvc];
    self.navigationController = nc;

    [fvc release];
    [nc release];

    // show them
    [self.window addSubview: nc.view];
    [self.window makeKeyAndVisible];

    return YES;
}

@end

FirstViewController is list view controller.

Answer 1

You are creating your window as a local variable and then trying to access it as if it were a property by using self.window. Make it a property.