With this following code, you can change the height of your UITextView depending of a fixed width (it's working on iOS 7 and previous version) :
- (CGFloat)textViewHeightForAttributedText:(NSAttributedString *)text andWidth:(CGFloat)width
{
UITextView *textView = [[UITextView alloc] init];
[textView setAttributedText:text];
CGSize size = [textView sizeThatFits:CGSizeMake(width, FLT_MAX)];
return size.height;
}
With this function, you will take a NSAttributedString and a fixed width to return the height needed.
If you want to calculate the frame from a text with a specific font you, need to use the following code :
- (CGSize)text:(NSString *)text sizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size
{
if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0"))
{
CGRect frame = [text boundingRectWithSize:size
options:(NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading)
attributes:@{NSFontAttributeName:font}
context:nil];
return frame.size;
}
else
{
return [text sizeWithFont:font constrainedToSize:size];
}
}
You can add that SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO
on your prefix.pch file in your project as:
#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)
You can also replace the previous test SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)
by :
if ([text respondsToSelector:@selector(boundingRectWithSize:options:attributes:context:)])