Question

I am inserting label in UIButton using addSubView

Here the label’s value will be change every time.

    UILabel *backTopLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 30, 448, 66)];
    backTopLabel.backgroundColor = [UIColor clearColor];
    backTopLabel.textColor = [UIColor whiteColor];
    backTopLabel.font = [UIFont fontWithName:@"Georgia" size:56];
    backTopLabel.textAlignment = UITextAlignmentCenter;

    backTopLabel.text = [[selectedUsers objectAtIndex:userIndex] valueForKey:@"FirstName"];   // UserIndex will be change and new data will be load in the label


    [btnBackLeftCard addSubview:backTopLabel];   // btnBackLeftCard is the UIButton
    [backTopLabel release];

The Problem is : It successfully changes the label value but it is over writing it.

I am getting the new label value over the old label value.

How can I solve this ?

Answer 1

Every time you call [[UILabel alloc] initWithFrame:CGRectMake(0, 30, 448, 66)] you are creating new memory, not accessing the existing memory.

So, you need to have something like

if(!backTopLabel)
    backTopLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 30, 448, 66)];

so that you only create the memory if it doesn’t exist.

However since your label isn’t a property, you’re essentially losing access to it anyway.
So you either need to add the label as a property of the class you’re in OR tag the view so you can find it again & remove it.

Tag it & find again like this:

for(UIView* labelView in btnBackLeftCard.subviews)
{
   if(labelView.tag = 100)
      [labelView removeFromSuperView];
}

UILabel *backTopLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 30, 448, 66)];
backTopLabel.backgroundColor = [UIColor clearColor];
backTopLabel.textColor = [UIColor whiteColor];
backTopLabel.font = [UIFont fontWithName:@"Georgia" size:56];
backTopLabel.textAlignment = UITextAlignmentCenter;

//here is where you tag the view, so you can find it again
backTopLabel.view.tag = 100;

backTopLabel.text = [[selectedUsers objectAtIndex:userIndex] valueForKey:@"FirstName"];   

[btnBackLeftCard addSubview:backTopLabel];   // btnBackLeftCard is the UIButton
[backTopLabel release];