Switching View through a function - iphone

Question

I'm working on an iPhone/iPad application and trying to switch views through a function call, not by a button. I've seen lots of sources switching views triggered by a button, but there's nothing that explains how to switch views triggered by a function. I tried to do this on my own, but it failed. Here's the code that I tried:
- (void)viewDidLoad
{
[super viewDidLoad];
if (self.webview == nil) {
self.webview = [[MainViewController alloc] init];
/* webview initialized with storyboard */
if (self.view.superview == nil) {
[self.view insertSubview:self.webview.view atIndex:0];
}
[storyboard release];
}
}
This is viewDidLoad of the viewController.m. First, it shows WebView.
- (void)changeView {
self.normview = [[AlternateViewController alloc] init];
/* normview initialized with storyboard */
[UIView beginAnimations:#"View Flip" context:nil];
[UIView setAnimationDuration:0.75];
[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.view cache:YES];
[self.webview viewWillDisappear:YES];
[self.webview viewDidDisappear:YES];
[self.webview.view removeFromSuperview];
[self.view insertSubview:self.normview.view atIndex:0];
[self.normview viewWillAppear:YES];
[self.normview viewDidAppear:YES];
[UIView commitAnimations];
}
And when this changeView function (in a viewController.m) is called, It should change the view from webview to normview (actually, it works fine when the same code is triggered by a button). But when I call this function in other file (not viewController.m), such as
ViewController *viewcontroller = [[ViewController alloc] init];
[viewcontroller changeView];
It doesn't work. Anyone can give a clue to solve this or an alternative way? (ps. I'm testing on iPad.)

Answer 1

You can switch views with this function:
YourView *screen = [[YourView alloc] initWithNibName:nil bundle:nil];
screen.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentModalViewController:screen animated:YES];
[screen release];
You can set the modaltransitionstyle to your willings.
Don't forget to import your headerfile at the top of your class.
#import "YourView.h"