I am starting an iPhone application, and I can't seem to get the main screen started. Here is my delegate.h file:
#import <UIKit/UIKit.h>
#class MainViewController;
#interface AppDelegate : UIResponder <UIApplicationDelegate>
#property (strong, nonatomic) UIWindow *window;
#property (retain, nonatomic) MainViewController *mainViewController;
#end
and here is my implementation file(at least the beginning):
#import "AppDelegate.h"
#import "MainViewController.h"
#implementation AppDelegate
#synthesize window = _window;
#synthesize mainViewController = _mainViewController;
- (void)dealloc
{
[_window release];
[_mainViewController];
[super dealloc];
}
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
MainViewController *aViewController = [[MainViewController alloc] initWithNibName:#"MainViewController" bundle:nil];
[self setMainViewController:aViewController];
[aViewController release];
self.window.rootViewController = self.mainViewController;
[self.window makeKeyAndVisible];
return YES;
}
When I try to run the app, just a black screen appears, and even after waiting a long time, the screen won't show the contents of my MainViewController.xib file...
Any ideas?
Main XIB of your application is MainWindow.xib. (It can be selected in project settings).
It contains app delegate, window and mainViewController (BTW, it should be better connected from XIB, not created manually in application:didFinishLaunching) connected to app delegate.
Check the connections.
Related
I want to create a app with only one view(TestViewController.h TestViewController.m). (no Tabbar, no Navigation Bar) Don't know why after i launch the app, the screen is totally black. It seems that the app did not load the view successfully? Since if the view is loaded, the screen should be white. Am I right or not?
Here's AppDelegate.h
#import <UIKit/UIKit.h>
#class TestViewController;
#interface AppDelegate : UIResponder <UIApplicationDelegate>
{
UIWindow *window;
TestViewController *testrViewController;
}
#property (strong, nonatomic) UIWindow *window;
#property (strong, nonatomic) TestViewController *testViewController;
#end
Here's AppDelegate.m
#import "AppDelegate.h"
#import "TestViewController.h"
#implementation AppDelegate
#synthesize window = window;
#synthesize testViewController;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[self.window addSubview:testViewController.view];
[self.window makeKeyAndVisible];
return YES;
}
It seems to me that you're not instatiating the class
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// add this line
testViewController = [[TestViewController alloc] init];
[.....]
}
Hope it helps
if you are creating it programmatically, then you should also instantiate window
UIWindow *aWindow = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window = aWindow;
[aWindow release];
then your ViewController
testViewController = [[TestViewController alloc] init];
and then make it visible
[self.window addSubview:testViewController.view];
[self.window makeKeyAndVisible];
did you create .xib for testViewController. If not then you have to add a subview over your testViewController. and then try. I hope it will work.
UIView *testView=[[UIView alloc]initwithFrame:CGRectMake(0,0,320,480)];
[testViewController addsubview:testView];
[self.window addSubview:testViewController.view];
[self.window makeKeyAndVisible];
EDIT: Working, see code below.
Working on an application, where right now I have the AppDelegate class, and a custom UINavigationController class. The code i have right now is pretty simple, and I feel like I've setup the XIB correctly. The build succeeds with no errors. But when the app launches, the navigationcontroller isnt displayed. I do not see the nav bar nor the table view. All I see is a blank screen. Here's the bulk of my code:
//
// FTPPhotosAppDelegate.h
// FTPPhotos
//
// Created by Aaron McLeod on 11-05-30.
// Copyright 2011 __MyCompanyName__. All rights reserved.
//
#import <UIKit/UIKit.h>
#import "RootViewController.h"
#interface FTPPhotosAppDelegate : NSObject <UIApplicationDelegate> {
UINavigationController *navigationController;
RootViewController *rootViewController;
}
#property (nonatomic, retain) UINavigationController *navigationController;
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) RootViewController *rootViewController;
#end
//
// FTPPhotosAppDelegate.m
// FTPPhotos
//
// Created by Aaron McLeod on 11-05-30.
// Copyright 2011 __MyCompanyName__. All rights reserved.
//
#import "FTPPhotosAppDelegate.h"
#implementation FTPPhotosAppDelegate
#synthesize window=_window;
#synthesize navigationController, rootViewController;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
navigationController = [[UINavigationController alloc] init];
rootViewController = [[RootViewController alloc] init];
[self.navigationController pushViewController:rootViewController animated:NO];
[self.window addSubview:[self.navigationController view]];
[self.window makeKeyAndVisible];
return YES;
}
#interface RootViewController : UITableViewController<UIImagePickerControllerDelegate> {
NSMutableArray *photos;
UIImagePickerController *picker;
UIBarButtonItem *addPhotoButton;
}
#property (nonatomic, retain) NSMutableArray *photos;
#property (nonatomic, retain) UIImagePickerController *picker;
#property (nonatomic, retain) IBOutlet UIBarButtonItem *addPhotoButton;
- (void) loadPhotos;
- (IBAction) addPhoto;
- (UIImage*)imageWithImage:(UIImage*)image scaledToSize:(CGSize)newSize;
#end
#import "RootViewController.h"
#implementation RootViewController
#synthesize photos, picker, addPhotoButton;
- (void)viewDidLoad
{
self.photos = [[NSMutableArray alloc] initWithCapacity:50];
[self loadPhotos];
[super viewDidLoad];
}
Any ideas? Here's a screenshot of the XIB,
.
Let me know if you need more info.
Instead of a root View controller, make it a UINavigationController *navigationController.
then in the applicationDidFinishLaunching, say
navigationController = [[UINavigationController alloc]init];
FirstViewController *firstView = [FirstViewController alloc]init];
[self pushViewController:firstView animated:NO];
firstView.title = #"TITLE";
[self addSubview:navigationController.view];
EDIT: some example code i have in an app of mine
AppDelegate.h
#import <UIKit/UIKit.h>
#interface DragonAge2AppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
UINavigationController *navigationController;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#end
AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
TitleClass *titlePage = [[TitleClass alloc]init];
navigationController = [[UINavigationController alloc]init];
titlePage.title = #"Dragon Age 2";
[navigationController pushViewController:titlePage animated:NO];
[titlePage release];
// Override point for customization after application launch.
[window addSubview:navigationController.view];
[self.window makeKeyAndVisible];
return YES;
}
You need to check some points:
Is the code in application:didFinishLaunchingWithOptions: executed when you run the application? Add a NSLog(#"app launched") in this code or set a breakpoint in it to check it. If it is not called, your FTPPhotosAppDelegate object is probably not set as the delegate of your UIApplication singleton in the XIB (this connection should be done by default if you created your app using a standard template, but it's worth checking)
Is the navigationController IBOutlet of your AppDelegate properly connected to your actual UINavigationController in the XIB? Check (using an NSLog or a breakpoint) that it is not nil.
Same for the view IBOutlet of the UINavigationController object in your XIB: check that it is properly connected and not nil.
A newbie Objective C question. Im trying to programmaticly change view from another view. But I only succeed in activating the tab button in the tabbarcontroller.
In my ViewDidLoad I have a condition that if thats not met, load the second view instead.
Is there any kind soul that can help out a Objective-C beginner? I have googled and search stackoverflow for the answer but with no luck.
FirstViewController.h
#interface FirstViewController : UIViewController {
some variables
}
some #properties
FirstViewController.m
#import "FirstViewController.h"
#implementation FirstViewController
- (void)viewDidLoad
{
if(condition is met) {
[self.tabBarController setSelectedIndex:1];
}
}
In my AppDelegate.h
#import <UIKit/UIKit.h>
#interface otpAppDelegate : NSObject <UIApplicationDelegate, UITabBarControllerDelegate> {
UIWindow *window;
UITabBarController *tabBarController;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) IBOutlet UITabBarController *tabBarController;
#end
AppDelegate.m
#implementation otpAppDelegate
#synthesize window;
#synthesize tabBarController;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[self.window addSubview:tabBarController.view];
[self.window makeKeyAndVisible];
tabBarController = [[UITabBarController alloc] init];
[tabBarController setDelegate:self];
return YES;
}
Edit!
I found a solution to my problem.
int selectedindex = 1;
self.tabBarController.selectedIndex = selectedindex;
UIViewController *tempvc = [[self.tabBarController viewControllers] objectAtIndex:selectedindex];
[self.view removeFromSuperview];
[self.view addSubview:tempvc.view];
Did the trick.
Try setting the index for the tabBarController instance of the app delegate like yourAppDelegate.tabBarController
If you are using tabBarController as IBOutlet , there is no need to allocate it in your app delegate. Please remove these code from your appDelegate method (application: didFinishLaunchingWithOptions)..
tabBarController = [[UITabBarController alloc] init];
[tabBarController setDelegate:self];
Probably just a simple question, but ive been building a little puzzle game and no decided i could do with a menu for it. Ive created the menu no problem i just cant get it to show before the puzzle. Ive tried changing the code in the appdelegate but its not liking it.
slider appdelegate.h
#import <UIKit/UIKit.h>
#class SliderViewController;
#class MainMenu;
#interface SliderAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
MainMenu *viewController1;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) IBOutlet SliderViewController *viewController;
#property (nonatomic, retain) IBOutlet MainMenu *viewController1;
#end
Slider appdelegate.m
#import "SliderAppDelegate.h"
#import "SliderViewController.h"
#implementation SliderAppDelegate
#synthesize window;
#synthesize viewController;
#synthesize viewController1;
#pragma mark -
#pragma mark Application lifecycle
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
// Add the view controller's view to the window and display.
[self.window addSubview:viewController1.view];
[self.window makeKeyAndVisible];
return YES;
}
But doing that throws out an error:
error: request for member 'view' in
something not a structure or union
I know its probably a stupid question but could anyone help please.
You need to import that class and make alloc the object first see this
Slider appdelegate.m
#import "SliderAppDelegate.h"
#import "SliderViewController.h"
#import "MainMenu.h"//change here
#implementation SliderAppDelegate
#synthesize window;
#synthesize viewController;
#synthesize viewController1;
#pragma mark -
#pragma mark Application lifecycle
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
viewController = [[[MainMenu alloc] initWithNibName#"MainMenu" bundle:nil] autorelease]; // and here
[self.window addSubview:viewController1.view];
[self.window makeKeyAndVisible];
return YES;
}
This is my first iPhone application and it's based on a top-level tableview. Selections of rows either go to another tableview or to a view. The application runs OK on the simulator but when ported to my iPhone it fails with a EXC_BAD_ACCESS error. This happens while my splash screen is being displayed. NSLog indicates that the program processes in appDelegate.m:
[window addSubview:[navigationController view]];
[window makeKeyAndVisible];
but then it just fails. The code never seems to reach the viewDidLoad in my RootViewController.
I'm sure that I've got the RootViewController and appDelegates mixed up somehow but cannot figure out exactly what's wrong. I've attached the beginning code of my RootViewController, appDelegate - any help appreciated.
RootViewController.h code....
#interface RootViewController : UITableViewController {
TyresViewController *tyresController;
EngineSpecViewController *engineSpecController;
CarbonTaxBandViewController *carbonTaxBandController;
TyreSpecificationsViewController *tyreSpecificationsController;
FuelConsumptionandEmissionsViewController *fuelConsumptionandEmissionsController;
CompanyCarTaxBandViewController *companyCarTaxBandController;
CarbonCalculatorViewController *carbonCalculatorController;
ReminderViewController *reminderController;
//NSString *selectedSpecification;
NSArray *listOfItems;
}
RootViewController.m code ......
#import "RootViewController.h"
#implementation RootViewController
#synthesize listOfItems;
//#synthesize selectedSpecification;
#synthesize carbonTaxBandController;
#synthesize engineSpecController;
#synthesize tyreSpecificationsController;
#synthesize tyresController;
#synthesize fuelConsumptionandEmissionsController;
#synthesize companyCarTaxBandController;
#synthesize carbonCalculatorController;
#synthesize reminderController;
appDelegate.h code.....
#interface MyCar3AppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
UINavigationController *navigationController;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) IBOutlet UINavigationController *navigationController;
#end
appDelegate.m code .....
- (void)applicationDidFinishLaunching:(UIApplication *)application {
// Override point for customization after app launch
[window addSubview:[navigationController view]];
[window makeKeyAndVisible];
}
Just a thought, in your main Info.plist file there should be an entry for Main nib file base name. This refers to the nib that will be loaded when your app starts. The simulator is not case sensitive, but the device is. Check the case of the value of your main nib.