如何设置UIButton的标题？

Question

How can we set the button title for a button,i know this answer its simple,we need to set the title of the button for title ,but my need is somewhat diffrent ,i had a username which dynamically changes according to login.i set this in a button click and display it in a label within that button .my code for this is

- (void)getFacebookProfileFinished:(ASIHTTPRequest *)request
{

    // Use when fetching text data
    NSString *responseString = [request responseString];
    NSLog(@"Got Facebook Profile: %@", responseString);

    NSString *likesString;
    NSMutableDictionary *responseJSON = [responseString JSONValue];   

    NSString *username;
    NSString *firstName = [responseJSON objectForKey:@"first_name"];
    NSString *lastName = [responseJSON objectForKey:@"last_name"];
    if (firstName && lastName) {
        username = [NSString stringWithFormat:@"%@ %@", firstName, lastName];
    } else {
        username = @"mysterious user";
    }
     [_loginButton setTitle:username forState:UIControlStateNormal];
    _lblfaceusername.text = username;


    [self refresh];    
}

i need to display the user name in another button click and have to assing the title of that button to user name the code for this is

- (void)refresh {
    if (_loginState == LoginStateStartup || _loginState == LoginStateLoggedOut) {
        _loginStatusLabel.text = @"Not connected to Facebook";
        [_loginButton setTitle:@"Login" forState:UIControlStateNormal];
        _loginButton.hidden = NO;
    } else if (_loginState == LoginStateLoggingIn) {
        _loginStatusLabel.text = @"Connecting to Facebook...";
        _loginButton.hidden = YES;
    } else if (_loginState == LoginStateLoggedIn) {
        _loginStatusLabel.text = @"Connected to Facebook";
        [_loginButton setTitle:@"" forState:UIControlStateNormal];
        _loginButton.hidden = NO;
    }   
}

i need to set the username in the [_loginButton setTitle:@"" forState:UIControlStateNormal]; i want [_loginButton setTitle:username forState:UIControlStateNormal] ;

Answer 1

Anyhow you have set the button title in the method

- (void)getFacebookProfileFinished:(ASIHTTPRequest *)request

after facebook request done. Then, why you need to set that again in refresh method? Just comment out the line in LoginStateLoggedIn condition in refresh method.

//[_loginButton setTitle:@"" forState:UIControlStateNormal];

Edit

- (void)refresh {
    if (_loginState == LoginStateStartup || _loginState == LoginStateLoggedOut) {
        _loginStatusLabel.text = @"Not connected to Facebook";
        [_loginButton setTitle:@"Login" forState:UIControlStateNormal];
        _loginButton.hidden = NO;
    } else if (_loginState == LoginStateLoggingIn) {
        _loginStatusLabel.text = @"Connecting to Facebook...";
        _loginButton.hidden = YES;
    } else if (_loginState == LoginStateLoggedIn) {
        _loginStatusLabel.text = @"Connected to Facebook";
        NSString *username = [_loginButton titleForState:UIControlStateNormal];
        [_loginButton setTitle:username forState:UIControlStateNormal];
        _loginButton.hidden = NO;
    }   
}

Answer 2

What you need is storing a reference to that message at a location that both pieces of code can access. The typical way to do so is to add a NSString * _username in your interface definition, and setting it to the username when you receive it. That way you can always access it from any location that depends on the current value of it.

Memory management included, that would yield:

[_username release]; // Release possible previous login
_username = [username retain]; // Ownership needed

In refresh:

[_loginButton setTitle:_username forState:UIControlStateNormal];

In dealloc:

[_username release]; // Release ownership when not needed anymore

This allows you to access your variable at any location desired.