例子1、解析JSON

char * json = "{ \"json\" : { \"id\":1, \"nodeId\":11, \"deviceId\":111, \"deviceName\":\"aaa\", \"ieee\":\"01212\", \"ep\":\"1111\", \"type\":\"bbb\" }}";

char * json1 = "{\"id\":1, \"nodeId\":11, \"deviceId\":111, \"deviceName\":\"aaa\"}";

cJSON * root;

cJSON * format;

int value_int;

char * value_string;

root = cJSON_Parse(json);

format = cJSON_GetObjectItem(root,"json");

value_int = cJSON_GetObjectItem(format,"nodeId")->valueint;

value_string = cJSON_GetObjectItem(format,"ieee")->valuestring;

printf( "%d\n", value_int );

printf( "%s\n", value_string );

cJSON_Delete(root);

root = cJSON_Parse(json1);

value_int = cJSON_GetObjectItem(root,"id")->valueint;

value_string = cJSON_GetObjectItem(root,"deviceName")->valuestring;

printf( "%d\n", value_int );

printf( "%s\n", value_string );

cJSON_Delete(root);例子二：生成JSON数据

cJSON* pRoot = cJSON_CreateObject();

cJSON* pArray = cJSON_CreateArray();

cJSON_AddItemToObject(pRoot, "students_info", pArray);

char* szOut = cJSON_Print(pRoot);

cJSON* pItem = cJSON_CreateObject();

cJSON_AddStringToObject(pItem, "name", "chenzhongjing");

cJSON_AddStringToObject(pItem, "sex", "male");

cJSON_AddNumberToObject(pItem, "age", 28);

cJSON_AddItemToArray(pArray, pItem);

pItem = cJSON_CreateObject();

cJSON_AddStringToObject(pItem, "name", "fengxuan");

cJSON_AddStringToObject(pItem, "sex", "male");

cJSON_AddNumberToObject(pItem, "age", 24);

cJSON_AddItemToArray(pArray, pItem);

pItem = cJSON_CreateObject();

cJSON_AddStringToObject(pItem, "name", "tuhui");

cJSON_AddStringToObject(pItem, "sex", "male");

cJSON_AddNumberToObject(pItem, "age", 22);

cJSON_AddItemToArray(pArray, pItem);

char* szJSON = cJSON_Print(pRoot);

cJSON_Delete(pRoot);

//free(szJSON);

pRoot = cJSON_Parse(szJSON);

pArray = cJSON_GetObjectItem(pRoot, "students_info");

if (NULL == pArray)

{

return -1;

}

int iCount = cJSON_GetArraySize(pArray);

for (int i = 0; i < iCount; ++i)

{

cJSON* pItem = cJSON_GetArrayItem(pArray, i);

if (NULL == pItem)

{

continue;

}

string strName = cJSON_GetObjectItem(pItem, "name")->valuestring;

string strSex = cJSON_GetObjectItem(pItem, "sex")->valuestring;

int iAge = cJSON_GetObjectItem(pItem, "age")->valueint;

}

cJSON_Delete(pRoot);

free(szJSON);