insertSubview: AtIndex: does not work - iphone

Question

I went through the material regarding this issue but still can't figure it out completely.
The main issue is that i am using this method but the view does not show...
The app is built out of two view - the main one (i added it as a subview to the main nib) -
Has of a text field where i write some text.
Has a button that when pressed, the action method loads a second view that has a label with some text in it.
the source code of the first viewController:
#import <UIKit/UIKit.h>
#class TxtRunnerViewController;
#interface Itai_s_text_app_take_2ViewController : UIViewController {
int sliderSpeed;
IBOutlet UITextField *textInput;
TxtRunnerViewController *trvc;
}
#property (nonatomic, retain) IBOutlet UITextField *textInput;
#property (retain, nonatomic) TxtRunnerViewController *trvc;
- (IBAction)sliderChanged:(id)sender;//speed of text show changed
- (IBAction)textFieldDoneEditing:(id)sender;//dor 'DONE' on keyboard
- (IBAction)backgroundTap:(id)sender;//for handling tapping on background
- (IBAction)textEmButtonPressed:(id)sender;
#end
the .m of the first ViewController:
#import "Itai_s_text_app_take_2ViewController.h"
#import "TxtRunnerViewController.h"
#implementation Itai_s_text_app_take_2ViewController
#synthesize textInput;
#synthesize trvc;
- (IBAction)sliderChanged:(id)sender
{
UISlider *slider = (UISlider *)sender;
sliderSpeed = (int)(slider.value + 0.5f);//setting the speed determinned by the usr in slider
NSLog(#"Slider value is %#", sliderSpeed);
}
- (IBAction)textFieldDoneEditing:(id)sender
{
[sender resignFirstResponder];
NSLog(#"our text input is %#", textInput.text);
}
- (IBAction)backgroundTap:(id)sender
{
[textInput resignFirstResponder];
}
- (IBAction)textEmButtonPressed:(id)sender
{
NSLog(#"button pressed");
if ([textInput.text length]==0)
{
NSString *msg = nil;
msg = #"Write text to transmit";
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Forgot something?"
message:msg
delegate:self
cancelButtonTitle:#"Back"
otherButtonTitles:nil];
[alert show];
[alert release];
[msg release];
}
else { //init
NSLog(#"HI!");
if (self.trvc == nil)
{
NSLog(#"if accepted");
TxtRunnerViewController *tr = [[TxtRunnerViewController alloc] initWithNibName:#"TxtRunner"
bundle:nil];
self.trvc = tr;
[tr release];
}
[self.view removeFromSuperview];
[self.view insertSubview:trvc.view atIndex:0];
NSLog(#"InsertAtIndex was operated...!");
//[self.view addSubview:tvc.view];
}
}
/*
// The designated initializer. Override to perform setup that is required before the view is loaded.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
*/
/*
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
}
*/
/*
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
[super viewDidLoad];
}
*/
/*
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
*/
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
if(self.trvc.view.superview == nil)
self.trvc = nil;
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[trvc release];
[super dealloc];
}
The second View is simply empty (has a label added to it in it's nib file):
#import
#interface TxtRunnerViewController : UIViewController {
}
#end
It's .m file is the default one, added no code to it.
When i press the button in the first view - it's view disappears but the second view does not appear instead, only a blank white view appears, nothing on it.
Doe

Answer 1

If you push the TxtRunnerViewController it will completely hide the first one, but it still exist in background. (without removeFromSuperview)
TxtRunnerViewController *vw = [[TxtRunnerViewController alloc]initWithNibName:#"TxtRunner" bundle:nil];
[self.view pushViewController:vw.view animated:NO];
[vw release];
To remove the first view it's a bit more difficult. You would need to implement a delegate in RootViewController which will be fired after clicking the done Button of the first view. Then in your RootViewController some code is executed which displays the second view and removes the first view.
For a delegate sample open the Utility Application Sample when creating a new project and figure out how it works or search some examples online.

Answer 2

The line:
[self.view removeFromSuperview];
Removes the view from its super
then the call
[self.view insertSubview:trvc.view atIndex:0];
Adds trvc to it - but that view has been removed and not visible anymore.
You need to add trvc to the superview.