iPhone dynamic addition of UILabel overlap - iphone

Question

I am parsing the XML file through URL and displaying the values as label dynamically.
If values are changed in xml file, the new values of labels are overlapped on old values
How should i fix it
In viewDidLoad
for(int i=0;i<[appDelegate.books count]; i++){
[self createLabel:labelname labelFrame:CGRectMake(LXCOOR, LYCOOR,LWIDTH,LHEIGHT)];
}
-(void) createLabel :(NSString * ) aTitle labelFrame:(CGRect) aFrame{
label1 =[[UILabel alloc] initWithFrame:aFrame];
//label.font=[UIFont fontWithName:#"Helvetica" size:TEXTSIZE];
label1.font=[UIFont systemFontOfSize: 10];
label1.textAlignment = UITextAlignmentLeft;
label1.text=[NSString stringWithString:aTitle];
label1.textColor=[UIColor blackColor];
label1.backgroundColor = [UIColor clearColor];
[sv addSubview:label1];
[self.view addSubview:sv];
}

Answer 1

remove the sv before adding it to the view...
-(void) createLabel :(NSString * ) aTitle labelFrame:(CGRect) aFrame{
if ([[sv subviews] count] > 0)
{
for(int i=0 ; i< [[sv subviews] count] ; i++)
{
UIView *subView = [[sv subviews] objectAtIndex:0];
[subView removeFromSuperview];
i++;
}
}
[sv removeFromSuperView];
label1 =[[UILabel alloc] initWithFrame:aFrame];
//label.font=[UIFont fontWithName:#"Helvetica" size:TEXTSIZE];
label1.font=[UIFont systemFontOfSize: 10];
label1.textAlignment = UITextAlignmentLeft;
label1.text=[NSString stringWithString:aTitle];
label1.textColor=[UIColor blackColor];
label1.backgroundColor = [UIColor clearColor];
[sv addSubview:label1];
[self.view addSubview:sv];
}

Answer 2

In viewDidLoad add,
[self.view addSubview:sv];
Then modify the "createLabel" function to
-(void) createLabel :(NSString * ) aTitle labelFrame:(CGRect) aFrame{
for(UIView *tempView in [sv subviews]) {
[subView removeFromSuperview];
}
label1 =[[UILabel alloc] initWithFrame:aFrame];
//label.font=[UIFont fontWithName:#"Helvetica" size:TEXTSIZE];
label1.font=[UIFont systemFontOfSize: 10];
label1.textAlignment = UITextAlignmentLeft;
label1.text=[NSString stringWithString:aTitle];
label1.textColor=[UIColor blackColor];
label1.backgroundColor = [UIColor clearColor];
[sv addSubview:label1];
}

Answer 3

as mentioned above, you shouldn't recreate the label over and over. Instead you should create one instance of it in viewDidLoad (or something that loads once)
-(void)viewDidLoad { ...
//code
CGRect aFrame = CGRectMake(x, y, width, height);
label1 =[[UILabel alloc] initWithFrame:aFrame];
[sv addSubview:label1];
[self.view addSubview:sv];
}
next you should call createLabel where you want to, for instance a button click or a scroll gesture. This should be your new createLabel without adding a subview
-(void) createLabel :(NSString * ) aTitle labelFrame:(CGRect) aFrame{
label1.font=[UIFont systemFontOfSize: 10];
label1.textAlignment = UITextAlignmentLeft;
label1.text=[NSString stringWithString:aTitle];
label1.textColor=[UIColor blackColor];
label1.backgroundColor = [UIColor clearColor];
}