Question

i am having a weird problem with uialert views.

i have several alerts are member variables in my .h file

UIAlertView *changepwalert;  //change password alert.
UIAlertView *delallalert;  //delete selected transactions.
UIAlertView *logout; //logout alert.
UIAlertView *closingbalancealert; //closing balance alert.
UIAlertView *totalreportalert; //total report alert.
UIAlertView *ordercashalert; //order cash alert.
UIAlertView *unlockingalert; //unlocking alert.
UIAlertView *receivecashalert;

in my .m file i have the following for didDismissWithButtonIndex delegate method.

if(alertView==unlockingalert && buttonIndex==0)
{
    //code
}

else if(alertView==ordercashalert && buttonIndex==0)
{
    //code

}
else if(alertView==receivecashalert && buttonIndex==0)
{
    //code
}
else if (alertView==logout && buttonIndex == 0)
{
    //code
}
else if(alertView==closingbalancealert && buttonIndex==0)
{
       //code
}
else if (alertView==changepwalert && buttonIndex==0)
{
    //code
}
else if(alertView==delallalert && buttonIndex==0)
{
    //code
}   

Here is a sample of how i am initializing the uialertview

ordercashalert = [[UIAlertView alloc] initWithTitle:nil message:@"Enter Password\n\n\n\n\n\n" delegate:self 
                                    cancelButtonTitle:@"Ok" otherButtonTitles:@"Cancel",nil];


logout = [[UIAlertView alloc] initWithTitle:@"Logout" message:@"Are You Sure?" delegate:self cancelButtonTitle:@"YES" otherButtonTitles:@"NO",nil];
[logout show];
[logout release];

when i click the logout button it runs the delegate method but it matches the alert to ordercashalert or receivecashalert.i am not sure why. it should actually match with logout alert. i am at the final stages of delivering the product and all of a sudden i have this bug. can some one help me please.

Answer 1

I’d suggest you use tag and enumeration trick. First – create enumeration for all possible alerts:

enum {
    RSChangePasswordAlertTag,
    RSDeleteAlertTag,
    ....
    ReceiveCashAlertTag
};

Then when creating the alert, just assign appropriate tag to it

UIAlertView *myAlert = [[[UIAlertView alloc] initWithTitle:....] autorelease];
[myAlert setTag:RSDeleteAlertTag];
[myAlert show];

Then in delegate method use switch statement for alertView‘s tag:

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSUInteger)buttonIndex {
    switch (alertView.tag) {
        case RSPasswordAlertTag: {
            // Do password alert thing
            break;
        }
        case RSDeleteAlertTag: { 
            // do delete thing
            break;
        }
        .... // here be other cases
    }
}

This way you’d be comparing only integers instead of pointers and your code will be cleaner with less instance variables.