Set line height in UITextView

After iOS 7, the styleString approach no longer works.

Two new alternatives are available.

Firstly, TextKit; a powerful new layout engine. To change line spacing, set the UITextView’s layout manager’s delegate:

textView.layoutManager.delegate = self; // you'll need to declare you implement the NSLayoutManagerDelegate protocol

Then override this delegate method:

- (CGFloat)layoutManager:(NSLayoutManager *)layoutManager lineSpacingAfterGlyphAtIndex:(NSUInteger)glyphIndex withProposedLineFragmentRect:(CGRect)rect
{
    return 20; // For really wide spacing; pick your own value
}

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Secondly, iOS 7 now supports NSParagraphStyle’s lineSpacing. This gives even more control, e.g. first line indentation, and calculation of a bounding rect. So alternatively…

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.headIndent = 15; // <--- indention if you need it
paragraphStyle.firstLineHeadIndent = 15;

paragraphStyle.lineSpacing = 7; // <--- magic line spacing here!

NSDictionary *attrsDictionary =
@{ NSParagraphStyleAttributeName: paragraphStyle }; // <-- there are many more attrs, e.g NSFontAttributeName

self.textView.attributedText = [[NSAttributedString alloc] initWithString:@"Hello World over many lines!" attributes:attrsDictionary];

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FWIW, the old contentInset method to align the text along the left edge of UITextView is also no use under iOS7. Instead, to remove the margin:

textView.textContainer.lineFragmentPadding = 0;