iOS label设置不同的字体 颜色

UILabel * lable = [[UILabel alloc] initWithFrame:CGRectMake(0, 70, 320, 40)];
lable.numberOfLines = 0;
//    lable.backgroundColor = [UIColor greenColor];
[self.view addSubview:lable];

NSString *string =
@"我是好人"@"我是好人"@"我是个好人"@"额鹅鹅鹅鹅鹅鹅饿"@"哇哇哇哇哇哇哇";
// 创建可变属性化字符串
NSMutableAttributedString *attrString =
[[NSMutableAttributedString alloc] initWithString:string];
//改变字符串当中从第18位置向后的10位数的字体
UIFont *smallFont = [UIFont systemFontOfSize:12];
[attrString addAttribute:NSFontAttributeName value:smallFont range:NSMakeRange(18, 10)];
//改变字符串当中第一个“1”的颜色
UIColor *rcolor = [UIColor redColor];

[attrString addAttribute:NSForegroundColorAttributeName value:rcolor range:[string rangeOfString:@"鹅"]];
lable.attributedText = attrString;