Scrolling to the end of UITextView's text - ios

Question

I have some contents in a view (such as images, labels) and the last item is a description (UITextView). Now I am trying to scroll the contents dynamically based on UITextView text. Here is my code:
- (void)viewDidAppear:(BOOL)animated {
_descriptions.scrollEnabled = NO;
[_descriptions sizeToFit];
_infoScrollView.contentSize = CGSizeMake(_contentsOnInfoView.frame.size.width,
_contentsOnInfoView.frame.size.height + _descriptions.frame.size.height);
}
Here is the result:
As you can see, there is lots of empty space. I need to scroll to the end of text.

Answer 1

I'd suggest you to try this.
[myTextView scrollRangeToVisible:NSMakeRange([myTextView.text length], 0)]

Answer 2

You should write you code in
-(void) viewDidLayoutSubviews {}
In this method,All components have frame according to running device size. and execute before appear the view.

Answer 3

//may be it will work for you
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc]init];
//set the line break mode
paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping;
NSDictionary *attrDict = [NSDictionary dictionaryWithObjectsAndKeys: description.font,
NSFontAttributeName,
paragraphStyle,
NSParagraphStyleAttributeName,
nil];
CGRect rect = [description.text boundingRectWithSize:CGSizeMake(description.size.width, FLT_MAX)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:attrDict
context:nil];
CGSize size = rect.size;
_infoScrollView.contentSize = CGSizeMake(_contentsOnInfoView.frame.size.width,description.frame.origin.y + size.height + 20)

Answer 4

I just found the answer,in the UI there is line that separates descriptions with the some infos ! I just calculate the line's y and sum up with the descriptions height :
_descriptions.scrollEnabled = NO;
[_descriptions sizeToFit];
_infoScrollView.contentSize = CGSizeMake(_infoView.frame.size.width, _line.frame.origin.y + _descriptions.bounds.size.height);
now it works fine !