在本地化 Objective-c 中连接两个字符串

Question

My Previous Code without Localization. It worked perfect.

case LOGIN_LOGOUT: ((Cell*)cell).lbl.text = [self isLoggedIn] ?   
[NSString stringWithFormat:@"Logout %@", email]   
:NSLocalizedString(@"Login", @"Message");
 break;  

But when I implement Localization in Logout the email will not show.

case LOGIN_LOGOUT: ((Cell*)cell).lbl.text = [self isLoggedIn] ?   
[NSString stringWithFormat:NSLocalizedString(@"Logout", @"Message") ,"%@",   
email] :NSLocalizedString(@"Login", @"Message");
break;  

I know I am missing some basics in stringWithFormat but can anyone offer some guidance to me?

Answer 1

You are looking up the localisation of "Logout". You are using that as a format string. That's not likely to work. Don't make statements that are too complex, it makes it impossible to debug.

I'd write

case LOGIN_LOGOUT: {
    NSString* labelText; 
    if ([self isLoggedIn]) {
        NSString* formatString = NSLocalizedString(@"Logout", @"Message");
        labelText = [NSString stringWithFormat:formatString, "%@", email];
    } else {
        labelText = NSLocalizedString(@"Login", @"Message");
    }

    ((Cell*)cell).lbl.text = labelText;
    break;
}

And now you can actually debug that whole mess. The stringWithFormat parameters look very, very dodgy.

Answer 2

Let's assume, that you have .strings file and it contains entry named "Logout" . You have:

[NSString stringWithFormat:NSLocalizedString(@"Logout", @"Message") ,"%@", email]

here you try to load format string via NSLocalizedString and use it with NSString . That means that you have to put correct format string into your .strings file, so, if currently you have:

"Logout" = "Logout";

In order to make it just like before localization, you need:

"Logout" = "Logout %@";

If you don't have a .strings file or don't have entry named "Logout" , NSLocalizedString will return the key, ie

NSLocalizedString(@"key", @"comment") // returns "key"

That means, that your NSLocalizedString(@"Logout", @"Message") may return "Logout" if NSLocalizedString can't find correct entry in your .strings file.

There are more things that may go wrong, if you want some deeper insides on that, I have written great article on the whole topic: Understanding iOS internationalization .

Also I'd suggest to use +localizedStringWithFormat: instead of just plain +stringWithFormat: , because the former uses current locale.