How to use NSString drawInRect to center text?

Vertical alignment you’ll have to do yourself ((height of view + height of string)/2). Horizontal alignment you can do with:

NSMutableParagraphStyle *style = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
style.alignment = NSTextAlignmentCenter;
NSDictionary *attr = [NSDictionary dictionaryWithObject:style forKey:NSParagraphStyleAttributeName];
[myString drawInRect:someRect withAttributes:attr];