adding interactive label to a window based iPhone application - objective-c

Question

I am trying to add a variable label to a simple window base iPhone application.
I am using XCode 3.2.6.
The app is an exaple I downloaded from the web and is just as simple as this:
a label where the user can type some text
a submit button
When the user clicks on submit, the text in the label is recorded in a mysql database with a simple query (the db is on my local machine and handled with a php script).
The query works, I just would like to add the label to write the result of the query.
So I added this code:
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 320.0f, 20.0f)];
[label setText:#"write some text"];
But it doesn't work.
Do I need to connect the label to some object in Interface Builder?
Thanks so much

Answer 1

i think you forget to add label to your view like this :
[self.view addSubView: label];
this will insert your label on your current view

Answer 2

UITextField sounds a better solution... With that, you can edit the message and set programmatically the text.
Doc: http://developer.apple.com/library/ios/#documentation/uikit/reference/UITextField_Class/Reference/UITextField.html

Answer 3

You should better make the UILabel *label as the property of the AppDelegate.
And then in the AppDelegate.m , you can init the UILabel
_label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 320.0f, 20.0f)];
At the end of your code of Launch , you should add the _label to the window bring the _label to front
[self.window addSubView:_label]
and in AppDelegate you should public a method to set the text.
- (void)showText:(NSString *)text
{
[_label setText:text];
[self.window bringSubviewToFront:_label];
}
And In your view or viewControll(should improt your AppDelegate.h) , when you click the submit button
- (void)clickSubmitButton:(UIButton)button
{
// TODO : get your text string
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate showText:YOURTEXT];
}

Answer 4

SOLVED!
I missed the #synthesize label !