cJSON结构：

typedef struct cJSON {
	struct cJSON *next,*prev;	/* next/prev allow you to walk array/object chains. Alternatively, use GetArraySize/GetArrayItem/GetObjectItem */
	struct cJSON *child;		/* An array or object item will have a child pointer pointing to a chain of the items in the array/object. */
	int type;					/* The type of the item, as above. */
	char *valuestring;			/* The item's string, if type==cJSON_String */
	int valueint;				/* The item's number, if type==cJSON_Number */
	double valuedouble;			/* The item's number, if type==cJSON_Number */
	char *string;				/* The item's name string, if this item is the child of, or is in the list of subitems of an object. */
} cJSON;

/* Supply a block ofJSON, and this returns a cJSON object you can interrogate. Call cJSON_Deletewhen finished. */

extern cJSON *cJSON_Parse(const char *value);//从 给定的json字符串中得到cjson对象

/* Render a cJSONentity to text for transfer/storage. Free the char* when finished. */

extern char *cJSON_Print(cJSON *item);//从cjson对象中获取有格式的json对象

/* Render a cJSONentity to text for transfer/storage without any formatting. Free the char* whenfinished. */

extern char *cJSON_PrintUnformatted(cJSON *item);//从cjson对象中获取无格式的json对象

 

/* Delete a cJSONentity and all subentities. */

extern void  cJSON_Delete(cJSON *c);//删除cjson对象，释放链表占用的内存空间

 

/* Returns thenumber of items in an array (or object). */

extern int   cJSON_GetArraySize(cJSON *array);//获取cjson对象数组成员的个数

/* Retrieve itemnumber "item" from array "array". Returns NULL ifunsuccessful. */

extern cJSON *cJSON_GetArrayItem(cJSON*array,int item);//根据下标获取cjosn对象数组中的对象

/* Get item"string" from object. Case insensitive. */

extern cJSON *cJSON_GetObjectItem(cJSON*object,const char *string);//根据键获取对应的值（cjson对象）

 

/* For analysingfailed parses. This returns a pointer to the parse error. You'll probably needto look a few chars back to make sense of it. Defined when cJSON_Parse()returns 0. 0 when cJSON_Parse() succeeds. */

extern const char *cJSON_GetErrorPtr(void);//获取错误字符串

示例：

//解析json字符串
#include<stdlib.h>
#include<stdio.h> 
#include <string.h>
#include <iostream>
#include "cJSON.h"
int main()
{   
      char* json = "{\"id\":\"1200000000\",\"number\":1}";
      cJSON * root_base = cJSON_Parse(json);//change to json object
      if(root_base )
      { printf("root_base is not null!\n ");        
        cJSON * cParse1 = cJSON_GetObjectItem(root_base,"id");
        cJSON * cParse2 = cJSON_GetObjectItem(root_base,"number");	 
        //get the value 
        std::string id = cParse->valuestring;
        std::string number= cParse->valueint;
        printf("id      :  %s\n",id.c_str()); 
        printf("number:  %d\n",number);  
        cJSON_Delete(root_base );//用完需要释放	 
     }
     return 0;
}

组json的常用函数：

cJSON * root  = cJSON_CreateObject();                    //创建JSON结构体
cJSON_AddNumberToObject(root, "number", 0);   //添加键值对
cJSON_AddStringToObject(root, "name", "i")  ;       //添加键值对

cJSON * root_arry = cJSON_CreateArray();//创建json数组型结构体

cJSON_AddItemToArray(root_arry,root); //为数组添加对象
cJSON_AddItemToObject(root_base, "array", root_array);//为对象添加数组

需要使用cjson时 可在工程中直接将以下文件作为源文件使用，官网可下载，应该也有相应的生成库，以下是我上传的文件链接：

文件： 点击打开链接