關於c++builderjson的信息

本文目錄一覽：

1、如何使用c語言獲取文件中的json數據
2、如何使用c builder
3、怎麼用C語言獲取JSON中的數據？
4、cbuilder是什麼?它與c++builder是一樣的嗎?
5、c語言解析json字符串
6、c++builder 6.0 裏面的json類在哪

如何使用c語言獲取文件中的json數據

直接文件操作就行了。fopen，然後直接讀出文件中的json數據，保存到一個數組裏面就行了

如何使用c builder

新建一個Console Application或者Console Wizard就可以調試C/C++程序了（無需保存工程，可以內存編譯），比VC++要簡單。

怎麼用C語言獲取JSON中的數據？

用C語言獲取JSON中的數據的方法是使用 CJSON。

以下簡單介紹用CJSON的思路及實現：

1）創建json，從json中獲取數據。

#nclude stdio.h

#include “cJSON.h”

char * makeJson()

{

cJSON * pJsonRoot = NULL;

pJsonRoot = cJSON_CreateObject();

if(NULL == pJsonRoot)

{

//error happend here

return NULL;

}

cJSON_AddStringToObject(pJsonRoot, “hello”, “hello world”);

cJSON_AddNumberToObject(pJsonRoot, “number”, 10010);

cJSON_AddBoolToObject(pJsonRoot, “bool”, 1);

cJSON * pSubJson = NULL;

pSubJson = cJSON_CreateObject();

if(NULL == pSubJson)

{

// create object faild, exit

cJSON_Delete(pJsonRoot);

return NULL;

}

cJSON_AddStringToObject(pSubJson, “subjsonobj”, “a sub json string”);

cJSON_AddItemToObject(pJsonRoot, “subobj”, pSubJson);

char * p = cJSON_Print(pJsonRoot);

// else use :

// char * p = cJSON_PrintUnformatted(pJsonRoot);

if(NULL == p)

{

//convert json list to string faild, exit

//because sub json pSubJson han been add to pJsonRoot, so just delete pJsonRoot, if you also delete pSubJson, it will coredump, and error is : double free

cJSON_Delete(pJsonRoot);

return NULL;

}

//free(p);

cJSON_Delete(pJsonRoot);

return p;

}

void parseJson(char * pMsg)

{

if(NULL == pMsg)

{

return;

}

cJSON * pJson = cJSON_Parse(pMsg)；

if(NULL == pJson)

{

// parse faild, return

return ;

}

// get string from json

cJSON * pSub = cJSON_GetObjectItem(pJson, “hello”);

if(NULL == pSub)

{

//get object named “hello” faild

}

printf(“obj_1 : %s\n”, pSub-valuestring);

// get number from json

pSub = cJSON_GetObjectItem(pJson, “number”);

if(NULL == pSub)

{

//get number from json faild

}

printf(“obj_2 : %d\n”, pSub-valueint);

// get bool from json

pSub = cJSON_GetObjectItem(pJson, “bool”);

if(NULL == pSub)

{

// get bool from json faild

}

printf(“obj_3 : %d\n”, pSub-valueint);

// get sub object

pSub = cJSON_GetObjectItem(pJson, “subobj”);

if(NULL == pSub)

{

// get sub object faild

}

cJSON * pSubSub = cJSON_GetObjectItem(pSub, “subjsonobj”);

if(NULL == pSubSub)

{

// get object from subject object faild

}

printf(“sub_obj_1 : %s\n”, pSubSub-valuestring);

cJSON_Delete(pJson);

}

int main()

{

char * p = makeJson();

if(NULL == p)

{

return 0;

}

printf(“%s\n”, p);

parseJson(p);

free(p);//這裡不要忘記釋放內存，cJSON_Print()函數或者cJSON_PrintUnformatted（）產生的內存，使用free(char *)進行釋放

return 0;

}

2）創建json數組和解析json數組

//創建數組，數組值是另一個JSON的item，這裡使用數字作為演示

char * makeArray(int iSize)

{

cJSON * root = cJSON_CreateArray();

if(NULL == root)

{

printf(“create json array faild\n”);

return NULL;

}

int i = 0;

for(i = 0; i iSize; i++)

{

cJSON_AddNumberToObject(root, “hehe”, i);

}

char * out = cJSON_Print(root);

cJSON_Delete(root);

return out;

}

//解析剛剛的CJSON數組

void parseArray(char * pJson)

{

if(NULL == pJson)

{

return ;

}

cJSON * root = NULL;

if((root = cJSON_Parse(pJson)) == NULL)

{

return ;

}

int iSize = cJSON_GetArraySize(root);

for(int iCnt = 0; iCnt iSize; iCnt++)

{

cJSON * pSub = cJSON_GetArrayItem(root, iCnt);

if(NULL == pSub)

{

continue;

}

int iValue = pSub-valueint;

printf(“value[%2d] : [%d]\n”, iCnt, iValue);

}

cJSON_Delete(root);

return;

}

有兩種方法：

一是標準的輸出輸入方式比如新建一個磁盤文件c:\a.txt，將鍵盤輸入的一字符串寫到文件中：

FILE *ft;

char str[50];

ft=fopen(“c:\\a.txt”,”w+”);

printf(“輸入一個字符串：”);

scanf(“%s”,str);

fputs(str,ft);

fclose(ft);

//重新打開這個文件並讀出字符串，顯示在屏幕上 ft=fopen(“c:\\a.txt”,”rt”);

fgets(str,50,ft);

fclose(ft); printf(“%s”,str);

二是低級輸入輸出方式仍如上例：

int hd; char str[50]; printf(“輸入一個字符串：”);

scanf(“%s”,str);

hd=open(“c:\\a.txt”,O_CREAT|O_TEXT|O_WRONLY);

write(hd,str,strlen(str));

close(hd); //重新打開這個文件並讀出字符串，顯示在屏幕上。

hd=open(“c:\\a.txt”,O_TEXT|O_RDONLY); read(hd,str,50);

close(hd); printf(“%s”,str)。

cbuilder是什麼?它與c++builder是一樣的嗎?

沒有聽說過什麼c

builder

呀，

Borland

C++

Builder

是Borland

公司開發的用於C/C++開發的IDE（

集成開發環境

）

1、沒有聽說過c

builder

2、如果有的話應該是差不多的

IDE，IDE是

編譯器

，

解釋器

，編緝器等的集合體

3、按字面解釋的話，c

builder

應該只能編譯C語言，C++

Builder

有一款開發環境就是Borland

公司的Borland

C++

Builder

，可以編譯C/

C++語言

。

c語言解析json字符串

你好，你用json-c庫，編譯通過了嗎？我是在ubuntu里使用json-c庫，但是無法編譯通過，報錯 undefined reference to ‘json_tokener_parse’，類似的函數沒定義的錯誤，你是怎麼調用的json-c庫？請教一下，謝謝！

c++builder 6.0 裏面的json類在哪

BCB6 不帶json的要2010版本的才有，不過建議自己寫一個用起來更方便

Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the “Software”), to deal

in the Software without restriction, including without limitation the rights

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

copies of the Software, and to permit persons to whom the Software is

furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in

all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

THE SOFTWARE.

#ifndef cJSON__h

#define cJSON__h

#ifdef __cplusplus

extern “C”

{

#endif

/* cJSON Types: */

#define cJSON_False 0

#define cJSON_True 1

#define cJSON_NULL 2

#define cJSON_Number 3

#define cJSON_String 4

#define cJSON_Array 5

#define cJSON_Object 6

#define cJSON_IsReference 256

/* The cJSON structure: */

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;

typedef struct cJSON_Hooks {

void *(*malloc_fn)(size_t sz);

void (*free_fn)(void *ptr);

} cJSON_Hooks;

/* Supply malloc, realloc and free functions to cJSON */

extern void cJSON_InitHooks(cJSON_Hooks* hooks);

/* Supply a block of JSON, and this returns a cJSON object you can interrogate. Call cJSON_Delete when finished. */

extern cJSON *cJSON_Parse(const char *value);

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

extern char *cJSON_Print(cJSON *item);

/* Render a cJSON entity to text for transfer/storage without any formatting. Free the char* when finished. */

extern char *cJSON_PrintUnformatted(cJSON *item);

/* Delete a cJSON entity and all subentities. */

extern void cJSON_Delete(cJSON *c);

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

extern int cJSON_GetArraySize(cJSON *array);

/* Retrieve item number “item” from array “array”. Returns NULL if unsuccessful. */

extern cJSON *cJSON_GetArrayItem(cJSON *array,int item);

/* Get item “string” from object. Case insensitive. */

extern cJSON *cJSON_GetObjectItem(cJSON *object,const char *string);

/* For analysing failed parses. This returns a pointer to the parse error. You’ll probably need to 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();

/* These calls create a cJSON item of the appropriate type. */

extern cJSON *cJSON_CreateNull();

extern cJSON *cJSON_CreateTrue();

extern cJSON *cJSON_CreateFalse();

extern cJSON *cJSON_CreateBool(int b);

extern cJSON *cJSON_CreateNumber(double num);

extern cJSON *cJSON_CreateString(const char *string);

extern cJSON *cJSON_CreateArray();

extern cJSON *cJSON_CreateObject();

/* These utilities create an Array of count items. */

extern cJSON *cJSON_CreateIntArray(int *numbers,int count);

extern cJSON *cJSON_CreateFloatArray(float *numbers,int count);

extern cJSON *cJSON_CreateDoubleArray(double *numbers,int count);

extern cJSON *cJSON_CreateStringArray(const char **strings,int count);

/* Append item to the specified array/object. */

extern void cJSON_AddItemToArray(cJSON *array, cJSON *item);

extern void cJSON_AddItemToObject(cJSON *object,const char *string,cJSON *item);

/* Append reference to item to the specified array/object. Use this when you want to add an existing cJSON to a new cJSON, but don’t want to corrupt your existing cJSON. */

extern void cJSON_AddItemReferenceToArray(cJSON *array, cJSON *item);

extern void cJSON_AddItemReferenceToObject(cJSON *object,const char *string,cJSON *item);

/* Remove/Detatch items from Arrays/Objects. */

extern cJSON *cJSON_DetachItemFromArray(cJSON *array,int which);

extern void cJSON_DeleteItemFromArray(cJSON *array,int which);

extern cJSON *cJSON_DetachItemFromObject(cJSON *object,const char *string);

extern void cJSON_DeleteItemFromObject(cJSON *object,const char *string);

/* Update array items. */

extern void cJSON_ReplaceItemInArray(cJSON *array,int which,cJSON *newitem);

extern void cJSON_ReplaceItemInObject(cJSON *object,const char *string,cJSON *newitem);

#define cJSON_AddNullToObject(object,name) cJSON_AddItemToObject(object, name, cJSON_CreateNull())

#define cJSON_AddTrueToObject(object,name) cJSON_AddItemToObject(object, name, cJSON_CreateTrue())

#define cJSON_AddFalseToObject(object,name) cJSON_AddItemToObject(object, name, cJSON_CreateFalse())

#define cJSON_AddNumberToObject(object,name,n) cJSON_AddItemToObject(object, name, cJSON_CreateNumber(n))

#define cJSON_AddStringToObject(object,name,s) cJSON_AddItemToObject(object, name, cJSON_CreateString(s))

#ifdef __cplusplus

}

#endif

原創文章，作者：小藍，如若轉載，請註明出處：https://www.506064.com/zh-hk/n/183764.html

關於c++builderjson的信息

本文目錄一覽：

如何使用c語言獲取文件中的json數據

如何使用c builder

怎麼用C語言獲取JSON中的數據？

cbuilder是什麼?它與c++builder是一樣的嗎?

c語言 解析json字符串

c++builder 6.0 裏面的json類在哪

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c語言解析json字符串