ios - Applying different attributes for different portions of an NSAttributedstring

Question

I know it is possible to apply attributes to an NSAttributedString.

But how can we apply different attributes to same attributed string.

for the string "This is an attributed text."

How can we set a particular attribute(background color or foreground color) to "This is" another attribute(background color or foreground color) to "an attributed text."

Is there any way to achieve this....?

Also is there any way to set the background color of an NSAttributedString in iOS?

Answer 1

Make a mutable copy of the attributed string, and then use either:

-setAttributes:range:
-addAttributes:range:
-addAttribute:value:range:
-removeAttributes:range:

for example, to set a red color for the first four letters:

NSMutableAttributedString *mutAttrStr = [attributedString mutableCopy];
CGColorRef redClr = [UIColor redColor].CGColor;
NSDictionary *newAttributes = [NSDictionary dictionaryWithObject:(id)redClr forKey:(id)kCTForegroundColorAttributeName];
[mutAttrStr addAttributes:newAttributes range:NSMakeRange(0, 4)];

http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSMutableAttributedString_Class/Reference/Reference.html

There's no built-in way to draw the background color on iOS. You can create a custom string constant for the attribute, eg "MyBackgroundColorAttributeName", and then you'll have to draw it yourself.