C#中两种方式转换Json的方法

方法一：拼接字符串

优点：自定义，灵活度高
缺点：编码容易出差错，还要处理末尾的元素

  string str = "{";
  for (int i = 0; i < list_head.Count; i++)
  {
       str += "\""+list_head[i]+"\":[";
       var value=list.Where(x => x.TypeName == list_head[i]).ToList();
          for (int j = 0; j < value.Count; j++)
                {
                    if (j== value.Count-1)
                    {
    str += "{\"ID\":\"" + value[j].ID + "\",\"Number\":\"" + value[j].Number + "\",\"TypeName\":\"" + value[j].TypeName + "\"}";
                    }
                    else
                    {
     str += "{\"ID\":\"" + value[j].ID + "\",\"Number\":\"" + value[j].Number + "\",\"TypeName\":\"" + value[j].TypeName + "\"},";
                    }
                }
                if (i== list_head.Count-1)
                {
                    str += "]";
                }
                else
                {
                    str += "],";
                }
            }
            str += "}";

方法二：使用第三方库（Newtonsoft）

优点：直接调用第三方封装好的方法，使用方便简洁
缺点：有版本的区别（其实也不算缺点），没有方法一灵活，其他都比较好

//模型类，定义Json结构
public class BaseModel
{
public List<ModelData> list_student { get; set; } = new List<ModelData>();
public List<ModelData> list_teacher { get; set; } = new List<ModelData>();
public List<ModelData> list_headteacher { get; set; } = new List<ModelData>();
public List<ModelData> list_gradedirector { get; set; } = new List<ModelData>();
public List<ModelData> list_deanr { get; set; } = new List<ModelData>();
}

//实例化，存储数据
BaseModel model = new BaseModel();
model.list_student = list.Where(x => x.TypeName == "学生").ToList();
model.list_teacher = list.Where(x => x.TypeName == "老师").ToList();
model.list_headteacher = list.Where(x => x.TypeName == "班主任").ToList();
model.list_gradedirector = list.Where(x => x.TypeName == "年级主任").ToList();
model.list_deanr = list.Where(x => x.TypeName == "院长").ToList();
string json2=JsonConvert.SerializeObject(model);

其他代码

//模型类
   public class ModelData
    {
        public ModelData(int iD, int number, string typeName)
        {
            ID = iD;
            Number = number;
            TypeName = typeName;
        }

        public int ID { get; set; }
        public int Number { get; set; }
        public string TypeName { get; set; }
    }

//测试数据
 class Program
    {
        static void Main(string[] args)
        {
            List<ModelData> list = new List<ModelData>(100);

            for (int i = 1; i <=100; i++)
            {
                if (i<50)
                {
                    list.Add(new ModelData(i, 10, "学生"));
                }
                else if (i>=50&&i<75)
                {
                    list.Add(new ModelData(i, 20, "老师"));
                }
                else if (i >= 75 && i <85)
                {
                    list.Add(new ModelData(i, 30, "班主任"));
                }
                else if (i >= 85 && i < 95)
                {
                    list.Add(new ModelData(i, 40, "年级主任"));
                }
                else
                {
                    list.Add(new ModelData(i, 40, "院长"));
                }
            }
            BaseModel model = new BaseModel();
            model.list_student = list.Where(x => x.TypeName == "学生").ToList();
            model.list_teacher = list.Where(x => x.TypeName == "老师").ToList();
            model.list_headteacher = list.Where(x => x.TypeName == "班主任").ToList();
            model.list_gradedirector = list.Where(x => x.TypeName == "年级主任").ToList();
            model.list_deanr = list.Where(x => x.TypeName == "院长").ToList();

            List<string> list_head = new List<string>() { "学生", "老师", "班主任", "年级主任","院长" };
            string str = "{";
            for (int i = 0; i < list_head.Count; i++)
            {
               str += "\""+list_head[i]+"\":[";
               var value=list.Where(x => x.TypeName == list_head[i]).ToList();
                for (int j = 0; j < value.Count; j++)
                {
                    if (j== value.Count-1)
                    {
                        str += "{\"ID\":\"" + value[j].ID + "\",\"Number\":\"" + value[j].Number + "\",\"TypeName\":\"" + value[j].TypeName + "\"}";
                    }
                    else
                    {
                        str += "{\"ID\":\"" + value[j].ID + "\",\"Number\":\"" + value[j].Number + "\",\"TypeName\":\"" + value[j].TypeName + "\"},";
                    }
                }
                if (i== list_head.Count-1)
                {
                    str += "]";
                }
                else
                {
                    str += "],";
                }
            }
            str += "}";
            Console.WriteLine(str);
            Console.WriteLine("-------------------------------------------------");
            string json2=JsonConvert.SerializeObject(model);
            Console.WriteLine(json2);

            Console.ReadKey();
        }

总结

方法二确实好，也有很多人使用，方法一也有自己的优点，如果格式唯一，改动小，可以直接使用方法二直接搞笑，如果格式经常需要改动，或者数据比较小的时候，用方法一，这个方便修改！主要是今天我用方法一做的程序，被老大说了，这种写法不好，直接否掉了，让我用第二种方法，在这记录一下！