Looping Through NSAttributedString Attributes to Increase Font SIze

Question

All I need is to loop through all attributes of NSAttributedString and increase their font size. So far I got to the point where I successfully loop through and manipulate attributes but I cannot save back to NSAttributedString. The line I commented out is not working for me. How to save back?

NSAttributedString *attrString = self.richTextEditor.attributedText;  [attrString enumerateAttributesInRange: NSMakeRange(0, attrString.string.length)                                options:NSAttributedStringEnumerationReverse usingBlock:  ^(NSDictionary *attributes, NSRange range, BOOL *stop) {       NSMutableDictionary *mutableAttributes = [NSMutableDictionary dictionaryWithDictionary:attributes];               UIFont *font = [mutableAttributes objectForKey:NSFontAttributeName];      UIFont *newFont = [UIFont fontWithName:font.fontName size:font.pointSize*2];               [mutableAttributes setObject:newFont forKey:NSFontAttributeName];      //Error: [self.richTextEditor.attributedText setAttributes:mutableAttributes range:range];      //no interfacce for setAttributes:range:   }]; 

Answer 1

Something like this should work:

NSMutableAttributedString *res = [self.richTextEditor.attributedText mutableCopy];  [res beginEditing]; __block BOOL found = NO; [res enumerateAttribute:NSFontAttributeName inRange:NSMakeRange(0, res.length) options:0 usingBlock:^(id value, NSRange range, BOOL *stop) {     if (value) {         UIFont *oldFont = (UIFont *)value;         UIFont *newFont = [oldFont fontWithSize:oldFont.pointSize * 2];         [res removeAttribute:NSFontAttributeName range:range];         [res addAttribute:NSFontAttributeName value:newFont range:range];         found = YES;     } }]; if (!found) {     // No font was found - do something else? } [res endEditing]; self.richTextEditor.attributedText = res; 

At this point res has a new attributed string with all fonts being twice their original size.