Change UILabel text in UIScrollView

Question

I'm trying to make an app in which there's a scrollview with frame and content size set from storyboard. i have inserted a label and both scrollview and uilabel have iboutlet created. i want to change text of uilabel each time i scroll with paging. content is saved in a nsmutable array as string. there's only single uilabel, and i wanna reuse it with content from array in every page of scroll view. please help..

The iOSDev The iOSDev · Accepted Answer · 2012-06-01T08:31:01

I think you need to use one of the method of UIScrollViewDelegate like scrollViewDidEndDecelerating: in this you can change the text of label and also the frame of the label to show it in visible rect of scrollview

- (void)scrollViewDidEndDecelerating:(UIScrollView *)ascrollView
{

    if(lastContentOffset < ascrollView.contentOffset.x)
    {
        if(index-2 >= 0)
        {
            [ascrollView addSubview:[thumbs objectAtIndex:index-2]];
            index-=1;
            //change label text using the index and also it's frame's origin.x
            NSLog(@"Direction Right Index %d",index);
        }
    }
    else if(lastContentOffset > ascrollView.contentOffset.x)
    {
        if(index+2 < [thumbs count])
        {
            [ascrollView addSubview:[thumbs objectAtIndex:index+2]];
            index+=1;
             //change label text using the index and also it's frame's origin.x
            NSLog(@"Direction Left Index %d",index);
        }
    }
    NSLog(@"ScrollViewDidScroll is called");
    lastContentOffset = ascrollView.contentOffset.x;
}

here the lastContentOffset is float variable which holds the current visible frame's x of the scrollview

in .m file declare two ivars below all the @synthesize as

NSMutableArray *arr; & float lastContentOffset;

then when you fill your scrollView just assign it's frame's origin.x to the lastContentOffset and then use the arr to change the text of label

Change UILabel text in UIScrollView

1 Answers