How to set margins (padding) in UITextView?

Starting from iOS 7 you can use textContainerInset property:

Objective-C

textView.textContainerInset = UIEdgeInsetsMake(0, 20, 0, 20);

Swift

textView.textContainerInset = UIEdgeInsets(top: 0, left: 20, bottom: 0, right: 20)

After fiddling around with this for a while I found another solution if you're only developing for iOS 6. Set the top and bottom margins with contentInset:

textView = [[UITextView alloc] init];
textView.contentInset = UIEdgeInsetsMake(20.0, 0.0, 20.0, 0.0);

For the left and right margins don't add your plain text right away but use an NSAttributedString instead with properly set left and right indents with an NSMutableParagraphStyle:

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.headIndent = 20.0;
paragraphStyle.firstLineHeadIndent = 20.0;
paragraphStyle.tailIndent = -20.0;

NSDictionary *attrsDictionary = @{NSFontAttributeName: [UIFont fontWithName:@"TrebuchetMS" size:12.0], NSParagraphStyleAttributeName: paragraphStyle};
textView.attributedText = [[NSAttributedString alloc] initWithString:myText attributes:attrsDictionary];

This gives you a UITextView with your text (in my case from the variable myText) with 20 pixels padding that properly scrolls.

Try this

UIBezierPath* aObjBezierPath = [UIBezierPath bezierPathWithRect:CGRectMake(0, 0, 20, 20)];
txtView.textContainer.exclusionPaths  = @[aObjBezierPath];