Switching between views in Objective C - ios

Question

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// UIScreen represents the entire screen. Its bounds method
// returns the rectangle that corresponds to the entire screen
// CGRect is a C struct that used to group four floating
// point values that represent the x and y coordinates of the upper left
// corner, as well as the width and the height.
//
CGRect windowRect = [[UIScreen mainScreen] nativeBounds];
UIWindow *window = [[UIWindow alloc] initWithFrame:windowRect];
[window setBackgroundColor:[UIColor lightGrayColor]];
[self setWindow:window];
UIViewController *vc = [[UIViewController alloc]init];
window.rootViewController = vc;
self.mainView = vc.view;
[window makeKeyAndVisible];
//Window is now visible
//Add created views to the mainView to make them visible.
//Example : add a "Hello World" label
UIView *dealerView=[[UIView alloc]initWithFrame:self.mainView.bounds];
UIView *view1=[[UIView alloc]initWithFrame:self.mainView.bounds];
CGRect labelRect = { 150.0, 150.0, 150.0, 50.0 };
UIButton *button1 = [[UIButton alloc] initWithFrame:labelRect];
[button1 setBackgroundColor:[UIColor blackColor]];
[button1 setTitle:#"ENTER HERE" forState: (UIControlState)UIControlStateNormal];
[button1 addTarget:self action:#selector(enterHereClicked:)
forControlEvents:UIControlEventTouchUpInside];
[button1 setUserInteractionEnabled:YES];
[view1 addSubview:button1];
[dealerView addSubview:view1];
return YES;
}
-(void) enterHereClicked:(UIButton *) button{
CGRect labelRect = { 150.0, 400.0, 150.0, 50.0 };
UIButton *sender=button;
UIView *view1=[sender superview];
UIView *view2=[[sender superview]superview];
[view1 removeFromSuperview];
UIView *view=[[UIView alloc]initWithFrame:self.mainView.bounds];
UIButton *button2 = [[UIButton alloc] initWithFrame:labelRect];
[button2 setBackgroundColor:[UIColor blackColor]];
[button2 setTitle:#"Another View" forState: (UIControlState)UIControlStateNormal];
[button2 addTarget:self action:#selector(clickView:) forControlEvents:
UIControlEventTouchUpInside];
[view addSubview:button2];
[view2 addSubview: view];
}
-(void)clickView:(UIButton *) button{
NSLog(#"anand");
UIButton *sender=button;
UIView *view1=[sender superview];
UIView *view3=[[sender superview]superview];
[view1 removeFromSuperview];
CGRect labelRect = { 150.0, 400.0, 150.0, 50.0 };
UIView *view=[[UIView alloc]initWithFrame:labelRect];
[view setBackgroundColor:[UIColor greenColor]];
[view3 addSubview:view];
}
I have edited the code as per you advise. But still not working.
I am creating a new view dealerview and adding and removing the subviews views from it. I am going somewhere wrong but still could not figure it out.
Looks like I am going wrong in the -(BOOL) application method.

Answer 1

It's very atypical to do this sort of thing in the app delegate. It would be better to do this in a subclass of UIViewController and add an instance of that subclass as the rootViewController of the UINavigationController you make key and visible in didFinishLaunchingWithOptions.
You also likely do not want to remove the root view of a UIViewController from it's super view. Currently, you care creating an action for a button that removes its superview, vc.view, from the view hierarchy. The problem is view1 and self.mainView are the same so with:
UIView *view1=[sender superview];
[view1 removeFromSuperview];
[self.mainView addSubview:view];
You're removing a view from the view hierarchy then adding a view to the view that's just been removed and expecting to see it.
You should have one view that acts as a container for button1 and another view that acts as a container for button2 but are both added and removed to/from self.mainView.

Answer 2

UIButton *addVehicleBackbtn=button;
UIView *addVehicleView=[addVehicleBackbtn superview];
[addVehicleView setHidden:YES];
I did hide the View using setHidden:YES in order to switch back between the views.