在iOS中切换View Controller的最佳方法

Question

I have 2 view controllers in my project. Inside View Controller1 I want to switch to View Controller 2 by press of a button. Currently I do this

- (IBAction)startController2:(id)sender {

viewController1 vc2 = [[viewController2 alloc] init];
self.view = vc2.view;
}

This seems to work fine, but there is a big delay (4 secs) between the button press and second view controller appears. If I call the viewController2 directly from the AppDelegate things load faster. What am I doing wrong here. Any help is greatly appreciated.

Answer 1

Several things to consider.

Part 1: "What am I doing wrong here"?

1. You definitely didn't mean to do self.view = vc2.view . You just put one view controller in charge of another view controller's view. What you probably mean to say was [self.view addSubview:vc2.view] . This alone might fix your problem, BUT ...

2. Don't actually use that solution. Even though it's almost directly from the samples in some popular iPhone programming books , it's a bad idea. Read "Abusing UIViewControllers" to understand why.

Part 2: What you should be doing

It's all in the chapter "Presenting View Controllers from Other View Controllers" .

It'll come down to either:

• a UINavigationController, (see the excellent Apple guide to them here ) and then you simply [navigationController pushViewController:vc2]

• a "manually managed" stack of modal view controllers, as andoabhay suggests

• explicitly adding a VC as child of another, as jason suggests

Answer 2

You should consider using UINavigationController to switch view controllers. If your building target is iOS 5.0+, you can also use the new controller container concept: [mainViewController addChildViewController:childViewController] .

Answer 3

Use presentModalViewController as follows

[self presentModalViewController:vc2 animated:YES completion:^(void){}];

and in the viewController1 use

[self dismissModalViewControllerAnimated:YES completion:^(void){}];

where ever you want to go back to previous controller.

Answer 4

[aController presentViewController:bController animated:NO completion:nil];
[bController presentViewController:cController animated:NO completion:nil];

when you want dismiss cController, you can do like this

[aController dismissViewControllerAnimated:NO completion:nil];

this is the flow chart.

aController → bController → cController
    ↑___________________________↓

Answer 5

You should use UINavigationController to switch view controllers.

You are on View1 and add the following code on button click method.

View2 *View2Controller = [[View2 alloc] initWithNibName:@"View2" bundle:nil]; [self.navigationController pushViewController:view2Controller animated:YES];