在Xcode上创建一个项目后，我删除了默认提供的viewController并创建了一个新的。 但是项目没有运行

Question

I created a project in Xcode and deleted the viewController file that comes by default in it. I added a new file(objective-c class) and added some controls in its viewDidLoad and run the project but it does not seem to work,the view it shows is blank. Is there any setting to be made?

Answer 1

When you say deleted the viewController file that comes by default in it. , that means that you have chosen application type other than Empty Application . That means most probably you might have chosen a Single view Application , as the defaultViewcontroller file will be provided with SingleView application( means with Storyboards by defaults on Xcode 5+).

So even if you have deleted the application, you can just

• add a NewViewController (subclassed from UIViewController ),
• name it ( myViewController )
• save it
• Import it in appDelegate File. ( #import "myViewController.h" )
• Create an instance of it.( myViewController *vc = [myViewController alloc]init] )
• Push it on navigationController

If you want to add buttons or anything else,

• just create objects in myViewController
• & instantiate them

• add them to SubViews.

  ---

  If you are using storyBoards, then

  • Add a new ViewController file & name it, something like myViewController
  • Add a new ViewControlelr object in the mainStoryboard file by drag & drop.
  • Select its inheriting class in the inspector on RHS, as myViewController
  • No need to modify anything in appDelegate file.
  • Make that controller in storyBoard as entryPoint. A default arrow will be preceding your controller.

    ---

hope that gives you the overview.

Answer 2

You have to set mainviewcontroller from didFinishLaunchingWithOptions method of appdelegate.m file.

as below

#import "Yourviewcontroller.h"

and in didFinishLaunchingWithOptions method:-

    self.viewController = [[YourViewControoler alloc] initWithNibName:@"Your xib file" bundle:nil];
self.navigationController = [[UINavigationController alloc] initWithRootViewController:self.viewController];
    self.window.rootViewController = self.navigationController;

I hope this will help you.

Answer 3

Yes. You have modify the AppDelegate file.

Suppose you add the new controller that name is DashboardViewController.

DashboardViewController.h

#import <UIKit/UIKit.h>

@class DashboardViewController;

@property (nonatomic,strong) DashboardViewController *viewController;


***DashboardViewController.m***



@synthesize viewController;


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
         self.viewController = [[DashboardViewController alloc] initWithNibName:@"DashboardViewController" bundle:nil];
   self.window.rootViewController = self.viewController;
   self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    return YES;
}