C++ RasDial之调用RasEnumEntries遍历系统中存在的宽带连接名称-优快云博客

本文链接：https://blog.youkuaiyun.com/zhi_qiu/article/details/38501483

本文展示了如何使用C++通过RasEnumEntries函数遍历并获取系统中的所有宽带连接名称。程序首先调用RasEnumEntries获取所需缓冲区大小，然后分配内存，再次调用该函数以枚举连接名称，并打印出来。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

#include <windows.h>
#include <iostream>
#include "ras.h"
#include "raserror.h"
#pragma comment(lib, "rasapi32.lib")

using namespace std;

DWORD  wmain(){

    DWORD dwCb = 0;
    DWORD dwRet = ERROR_SUCCESS;
    DWORD dwEntries = 0;
    LPRASENTRYNAME lpRasEntryName = NULL;

    // Call RasEnumEntries with lpRasEntryName = NULL. dwCb is returned with the required buffer size and
    // a return code of ERROR_BUFFER_TOO_SMALL
    // 用lpRasEntryName = NULL 来调用 RasEnumEntries, 其中dwCb是一个传出值, 用来返回成功调用所需的缓冲区的字节数.

    dwRet = RasEnumEntries(NULL, NULL, lpRasEntryName, &dwCb, &dwEntries);

    // 函数成功返回0
    if (dwRet == ERROR_BUFFER_TOO_SMALL){

        // Allocate the memory needed for the array of RAS entry names.
        // 分配遍历条目所需要的字节输

        lpRasEntryName = (LPRASENTRYNAME) HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, dwCb);

        // 如果lpRasEntryName指针为NULL, 则说明分配内存失败

        if (lpRasEntryName == NULL){
            // cout << "HeapAlloc failed!" << endl;
            cout << "分配内存失败! " << endl;
            return 0;
        }

        // The first RASENTRYNAME structure in the array must contain the structure size
        // 数组中第一个 RASENRTYNAME 结构必须包含结构体的大小

        lpRasEntryName[0].dwSize = sizeof(RASENTRYNAME);

        // Call RasEnumEntries to enumerate all RAS entry names
        // 调用 RasEnumEntries 枚举所有的连接名称

        dwRet = RasEnumEntries(NULL, NULL, lpRasEntryName, &dwCb, &dwEntries);

        // If successful, print the RAS entry names
        // 如果调用成功, 打印出每个连接的名称

        if (ERROR_SUCCESS == dwRet){
            // cout <<  "The following RAS entry names were found:" << endl;
            cout << "枚举出的连接的名称：" << endl;
            for (DWORD i = 0; i < dwEntries; i++){
                cout << lpRasEntryName[i].szEntryName << endl;
            }
        }

        // Deallocate memory for the connection buffer
        // 释放用于存放连接名称的内存
        HeapFree(GetProcessHeap(), 0, lpRasEntryName);

        // 赋值空指针
        lpRasEntryName = NULL;
    }else {

        // There was either a problem with RAS or there are RAS entry names to enumerate
        // 枚举连接名称出现的问题

        if(dwEntries >= 1){

            // cout << "The operation failed to acquire the buffer size." << endl;
            cout << "以上操作未能获取缓冲区的大小. " << endl;
        }else{

            // cout << "There were no RAS entry names found:." << endl;
            cout << "系统中没有RAS连接. " << endl;
        }
    }
    cin.get ();
    return 0;
}