NSMutableAttributedString 富文本的使用

//富文本的使用
    UILabel *testLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, 100, 320, 30)];
    
    testLabel.backgroundColor = [UIColor lightGrayColor];
    
    testLabel.textAlignment = NSTextAlignmentCenter;
    
    NSMutableAttributedString *AttributedStr = [[NSMutableAttributedString alloc]initWithString:@"今天天气不错呀"];
    
    [AttributedStr addAttribute:NSFontAttributeName
     
                          value:[UIFont systemFontOfSize:25.0]
     
                          range:NSMakeRange(2, 2)];
    
    [AttributedStr addAttribute:NSForegroundColorAttributeName
     
                          value:[UIColor redColor]
     
                          range:NSMakeRange(2, 2)];
    
    testLabel.attributedText = AttributedStr;
    
    [self.view addSubview:testLabel];