Label文字多种颜色

NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"总共%@题",numStr]];      [str addAttribute:NSForegroundColorAttributeName value:DOMINICAL_COLOR range:NSMakeRange(0,2)];      [str addAttribute:NSForegroundColorAttributeName value:SHALLOW_GREEN_COLOR range:NSMakeRange(2,numStr.length)];      [str addAttribute:NSForegroundColorAttributeName value:DOMINICAL_COLOR range:NSMakeRange(2+numStr.length,1)];            UILabel *titleLabel3 = [[UILabel alloc] initWithFrame:CGRectMake(5, CGRectGetMaxY(lineView.frame)+5, 100, 20)];      titleLabel3.backgroundColor = [UIColor clearColor];      titleLabel3.font = MBLACK15_FONT;      titleLabel3.attributedText = str;      [self addSubview:titleLabel3];