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C++法式中應用Windows體系Native Wifi API的根本教程

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C++法式中應用Windows體系Native Wifi API的根本教程。本站提示廣大學習愛好者：（C++法式中應用Windows體系Native Wifi API的根本教程）文章只能為提供參考，不一定能成為您想要的結果。以下是C++法式中應用Windows體系Native Wifi API的根本教程正文

Windows運用想要完成銜接wifi，監聽wifi旌旗燈號，斷開銜接等功效，用NativeWifi API是個不錯的選擇。

翻開MSDN,搜刮NativeWifi Api，找到Native Wifi頁。在這裡。

信息量很年夜，假如像我焦急完成上述功效，看海量的文檔有些來不及。假如直接給我例子，在運轉中調試，浏覽代碼，效力會更高。
然則，我並沒有勝利。起首，Sample在SDK中，拜見這裡。我下載幾回都掉敗了，最初廢棄這條路。後來同事給了我一份Sample，我不敢肯定能否就是這個，然則代碼寫的也是很艱澀。我的初志是簡略的應用這些API的例子。

看來照樣本身著手吧。看相干API，假如不懂，就找有經歷人的例子。

幾經周折，終究完成我的需求。讓我漸漸道來。
1.取得可用AP列表
拜見WlanGetAvailableNetworkList的官方文檔，上面有例子。

DWORD WINAPI WlanGetAvailableNetworkList( 
 _In_  HANDLE hClientHandle, 
 _In_  const GUID *pInterfaceGuid, 
 _In_  DWORD dwFlags, 
 _Reserved_ PVOID pReserved, 
 _Out_  PWLAN_AVAILABLE_NETWORK_LIST *ppAvailableNetworkList 
);

由可用列表即可以找到以後哪一個AP正在銜接，並顯示旌旗燈號強度。
2.監聽以後銜接
在取得可用AP列表的基本上，遍歷以後AP，看誰正在銜接，並獲得它的旌旗燈號。代碼片斷以下：

bool isConnect = false; 
int numberOfItems = pWLAN_AVAILABLE_NETWORK_LIST->dwNumberOfItems; 
  for(int i = 0; i <= numberOfItems; i++) 
  { 
   WLAN_AVAILABLE_NETWORK wlanAN = pWLAN_AVAILABLE_NETWORK_LIST->Network[i]; 
   if(wlanAN.dwFlags & WLAN_AVAILABLE_NETWORK_CONNECTED) 
   { 
    Wprintf(WLAN signal is %s:%d\n", wlanAN.strProfileName, wlanAN.wlanSignalQuality); 
    isConnect = true;     
   } 
  } 
  if(!isConnect){    
 wprintf("Wifi is disconnected!\n");}

3.斷開銜接
假如wifi處於銜接狀況，將其斷開。WlanDisconnect照樣輕易應用的。原型以下：

DWORD WINAPI WlanDisconnect( 
 _In_  HANDLE hClientHandle, 
 _In_  const GUID *pInterfaceGuid, 
 _Reserved_ PVOID pReserved 
);

代碼演示在前面。
4.銜接一個有profile的AP（已保留過暗碼）
這是本文的重點。
固然銜接函數WlanConnect原型很簡略：

DWORD WINAPI WlanConnect( 
 _In_  HANDLE hClientHandle, 
 _In_  const GUID *pInterfaceGuid, 
 _In_  const PWLAN_CONNECTION_PARAMETERS pConnectionParameters, 
 _Reserved_ PVOID pReserved 
);

但參數PWLAN_CONNECTION_PARAMETERS倒是很龐雜，只需有一個配錯，銜接就會掉敗。
還好我的需求照樣蠻簡略的，只需銜接已有的profile的AP。那末我的任務就會有針對性的展開。波折了很多多少天，每次都銜接掉敗，緣由是ERROR_INVALID_PARAMETER。
就在明天，我終究勝利了。真是會者不難，難者不會啊。
看看銜接參數的構造體：

typedef struct _WLAN_CONNECTION_PARAMETERS { 
 WLAN_CONNECTION_MODE wlanConnectionMode; 
 LPCWSTR    strProfile; 
 PDOT11_SSID   pDot11Ssid; 
 PDOT11_BSSID_LIST pDesiredBssidList; 
 DOT11_BSS_TYPE  dot11BssType; 
 DWORD    dwFlags; 
} WLAN_CONNECTION_PARAMETERS, *PWLAN_CONNECTION_PARAMETERS;

為了完成我的請求，可以如許賦值：
wlanConnectionMode這裡設成wlan_connection_mode_profile；
strProfile寫上你要銜接ap的稱號（平日是profile稱號）；
pDot11Ssid用不上，設置NULL；
pDesiredBssidList異樣置成NULL；
dot11BssType我給設成dot11_BSS_type_infrastructure（基本舉措措施？）；
dwFlags設置為WLAN_CONNECTION_HIDDEN_NETWORK。
確切是任務了，strProfile若何獲得呢？拜見監聽銜接旌旗燈號中對可用AP列表中第一個profile的獲得。
完全代碼以下：

// 
#include "stdafx.h" 
#include <windows.h> 
#include <wlanapi.h> 
#include <objbase.h> 
#include <wtypes.h> 
#include <string> 
#include <stdio.h> 
#include <stdlib.h> 
 
// Need to link with Wlanapi.lib and Ole32.lib 
#pragma comment(lib, "wlanapi.lib") 
#pragma comment(lib, "ole32.lib") 
 
using namespace std; 
 
int listenStatus() 
{ 
 HANDLE hClient = NULL; 
 DWORD dwMaxClient = 2;   
 DWORD dwCurVersion = 0; 
 DWORD dwResult = 0; 
 DWORD dwRetVal = 0; 
 int iRet = 0; 
  
 WCHAR GuidString[39] = {0}; 
 //Listen the status of the AP you connected. 
 while(1){ 
  Sleep(5000); 
  PWLAN_INTERFACE_INFO_LIST pIfList = NULL;//I think wlan interface means network card 
  PWLAN_INTERFACE_INFO pIfInfo = NULL; 
 
  DWORD dwFlags = 0;   
  
  dwResult = WlanOpenHandle(dwMaxClient, NULL, &dwCurVersion, &hClient); 
  if (dwResult != ERROR_SUCCESS) { 
   wprintf(L"WlanOpenHandle failed with error: %u\n", dwResult); 
   return 1; 
  } 
 
  dwResult = WlanEnumInterfaces(hClient, NULL, &pIfList); 
  if (dwResult != ERROR_SUCCESS) { 
   wprintf(L"WlanEnumInterfaces failed with error: %u\n", dwResult); 
   return 1; 
  } else { 
 
   wprintf(L"WLAN_INTERFACE_INFO_LIST for this system\n"); 
 
   wprintf(L"Num Entries: %lu\n", pIfList->dwNumberOfItems); 
   wprintf(L"Current Index: %lu\n\n", pIfList->dwIndex); 
   int i; 
   for (i = 0; i < (int) pIfList->dwNumberOfItems; i++) { 
    pIfInfo = (WLAN_INTERFACE_INFO *) &pIfList->InterfaceInfo[i]; 
    wprintf(L" Interface Index[%u]:\t %lu\n", i, i); 
    iRet = StringFromGUID2(pIfInfo->InterfaceGuid, (LPOLESTR) &GuidString, 
     sizeof(GuidString)/sizeof(*GuidString)); 
 
    if (iRet == 0) 
     wprintf(L"StringFromGUID2 failed\n"); 
    else { 
     wprintf(L" InterfaceGUID[%d]: %ws\n",i, GuidString); 
    }  
    wprintf(L" Interface Description[%d]: %ws", i, 
     pIfInfo->strInterfaceDescription); 
    wprintf(L"\n"); 
 
    wprintf(L" Interface State[%d]:\t ", i); 
    switch (pIfInfo->isState) { 
    case wlan_interface_state_not_ready: 
     wprintf(L"Not ready\n"); 
     break; 
    case wlan_interface_state_connected: 
     wprintf(L"Connected\n"); 
     break; 
    case wlan_interface_state_ad_hoc_network_formed: 
     wprintf(L"First node in a ad hoc network\n"); 
     break; 
    case wlan_interface_state_disconnecting: 
     wprintf(L"Disconnecting\n"); 
     break; 
    case wlan_interface_state_disconnected: 
     wprintf(L"Not connected\n"); 
     break; 
    case wlan_interface_state_associating: 
     wprintf(L"Attempting to associate with a network\n"); 
     break; 
    case wlan_interface_state_discovering: 
     wprintf(L"Auto configuration is discovering settings for the network\n"); 
     break; 
    case wlan_interface_state_authenticating: 
     wprintf(L"In process of authenticating\n"); 
     break; 
    default: 
     wprintf(L"Unknown state %ld\n", pIfInfo->isState); 
     break; 
    } 
   } 
  } 
 } 
} 
 
int _tmain(int argc, _TCHAR* argv[]) 
{ 
 
 HANDLE hClient = NULL; 
 DWORD dwMaxClient = 2;   
 DWORD dwCurVersion = 0; 
 DWORD dwResult = 0; 
 DWORD dwRetVal = 0; 
 int iRet = 0;  
 
 /* variables used for WlanEnumInterfaces */ 
 
 PWLAN_INTERFACE_INFO_LIST pIfList = NULL; 
 PWLAN_INTERFACE_INFO pIfInfo = NULL; 
 
 LPCWSTR pProfileName = NULL; 
 LPWSTR pProfileXml = NULL; 
 DWORD dwFlags = 0; 
  
 pProfileName = argv[1]; 
  
 wprintf(L"Information for profile: %ws\n\n", pProfileName); 
  
 dwResult = WlanOpenHandle(dwMaxClient, NULL, &dwCurVersion, &hClient); 
 if (dwResult != ERROR_SUCCESS) { 
  wprintf(L"WlanOpenHandle failed with error: %u\n", dwResult); 
  return 1; 
 } 
 
 dwResult = WlanEnumInterfaces(hClient, NULL, &pIfList); 
 if (dwResult != ERROR_SUCCESS) { 
  wprintf(L"WlanEnumInterfaces failed with error: %u\n", dwResult); 
  return 1; 
 } else { 
  dwResult = WlanDisconnect(hClient, &pIfList->InterfaceInfo[0].InterfaceGuid,NULL);//DISCONNECT FIRST 
  if(dwResult != ERROR_SUCCESS) 
  { 
   printf("WlanDisconnect failed with error: %u\n",dwResult); 
   return -1; 
  } 
  PWLAN_AVAILABLE_NETWORK_LIST pWLAN_AVAILABLE_NETWORK_LIST = NULL; 
  dwResult = WlanGetAvailableNetworkList(hClient, &pIfList->InterfaceInfo[0].InterfaceGuid, 
    WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_MANUAL_HIDDEN_PROFILES, 
    NULL, &pWLAN_AVAILABLE_NETWORK_LIST); 
  if (dwResult != ERROR_SUCCESS) 
  {    
   printf("WlanGetAvailableNetworkList failed with error: %u\n",dwResult); 
   WlanFreeMemory(pWLAN_AVAILABLE_NETWORK_LIST); 
   return -1; 
  } 
  WLAN_AVAILABLE_NETWORK wlanAN = pWLAN_AVAILABLE_NETWORK_LIST->Network[0];//PLEASE CHECK THIS YOURSELF 
  if(pProfileName == NULL) 
   pProfileName = wlanAN.strProfileName;  
  WLAN_CONNECTION_PARAMETERS wlanConnPara; 
  wlanConnPara.wlanConnectionMode =wlan_connection_mode_profile ; //YES,WE CONNECT AP VIA THE PROFILE 
  wlanConnPara.strProfile =pProfileName;       // set the profile name 
  wlanConnPara.pDot11Ssid = NULL;         // SET SSID NULL 
  wlanConnPara.dot11BssType = dot11_BSS_type_infrastructure;  //dot11_BSS_type_any,I do not need it this time.   
  wlanConnPara.pDesiredBssidList = NULL;       // the desired BSSID list is empty 
  wlanConnPara.dwFlags = WLAN_CONNECTION_HIDDEN_NETWORK;   //it works on my WIN7\8 
 
  dwResult=WlanConnect(hClient,&pIfList->InterfaceInfo[0].InterfaceGuid,&wlanConnPara ,NULL); 
  if (dwResult==ERROR_SUCCESS) 
  { 
   printf("WlanConnect success!\n"); 
  } 
  else 
  { 
   printf("WlanConnect failed err is %d\n",dwResult); 
  } 
 } 
 
 listenStatus(); //LISTEN THE STATUS 
 
 if (pProfileXml != NULL) { 
  WlanFreeMemory(pProfileXml); 
  pProfileXml = NULL; 
 } 
 
 if (pIfList != NULL) { 
  WlanFreeMemory(pIfList); 
  pIfList = NULL; 
 } 
 return dwRetVal; 
}

5.翻開收集設置界面
碰到之前沒有銜接過的AP，須要輸出暗碼，那末，直接翻開設置裝備擺設界面讓用戶本身來弄吧。

ShellExecute( 
 NULL, 
 L"open", 
 L"shell:::{21EC2020-3AEA-1069-A2DD-08002B30309D}\\::{38a98528-6cbf-4ca9-8dc0-b1e1d10f7b1b}", 
 NULL, 
 NULL, 
 SW_SHOWNORMAL);

6.RSSI
當屏幕上打印出“WlanConnect success!”的時刻，別提多愉快了。
就像愛迪生實驗燈絲一下，在有數次掉敗後，終究找到了一種資料可以勝任燈絲的任務。這類喜悅真的使人振奮，昔日的陰霾和不爽終究一掃而空。
其實我也測驗考試過WlanGetProfile和WlanSetProfile，固然有時成果是可以或許連上指定AP，然則函數前往成果卻老是ERROR_INVALID_PARAMETER。
網上的例子，許多都是抄來抄去的，寫的不明不白，固然有過贊助，然則也有些誤導。
明天本身勝利的銜接到指定AP了（用敕令交運行我的例子，輸出參數profile name），我必定要把它揭橥出來，讓其別人有個參考。
我以為這是一件誠意的作品，在此也感謝給過我贊助的同伙。
最初說一下取得的旌旗燈號。尺度旌旗燈號RSSI是負值，而這裡取得的旌旗燈號都是正值（0~100），在有些須要RSSI的處所，我們須要轉換一下：

if (pBssEntry->wlanSignalQuality == 0) 
  iRSSI = -100; 
 else if (pBssEntry->wlanSignalQuality == 100)  
  iRSSI = -50; 
 else 
  iRSSI = -100 + (pBssEntry->wlanSignalQuality/2);  
  
 wprintf(L" Signal Quality[%u]:\t %u (RSSI: %i dBm)\n", j, 
  pBssEntry->wlanSignalQuality, iRSSI);

7.Wifi on與wifi off
上面要說的是在軟件層面掌握無線網卡的開和關。
成績聽起來簡略，查詢拜訪起來龐雜，但處理起來卻也簡略。症結函數就是Native wifi api中的WlanSetInterface。其實這個API功效也長短
常壯大的，我只用到個中掌握wifi radio state的功效。官網文檔在此。
函數原型：

DWORD WINAPI WlanSetInterface( 
 _In_  HANDLE hClientHandle, 
 _In_  const GUID *pInterfaceGuid, 
 _In_  WLAN_INTF_OPCODE OpCode, 
 _In_  DWORD dwDataSize, 
 _In_  const PVOID pData, 
 _Reserved_ PVOID pReserved 
);

重點說一下三個參數：
（1） OpCode，指定要設置的參數。我們選擇wlan_intf_opcode_radio_state
（2） DwDataSize，pData的size。傳入時用sizeof獲得。
（3） pData，radio state對應的data是WLAN_PHY_RADIO_STATE。
看看這個state構造體：

typedef struct _WLAN_PHY_RADIO_STATE { 
 DWORD    dwPhyIndex; 
 DOT11_RADIO_STATE dot11SoftwareRadioState; 
 DOT11_RADIO_STATE dot11HardwareRadioState; 
} WLAN_PHY_RADIO_STATE, *PWLAN_PHY_RADIO_STATE;

Index設為0.
State設置以下：

typedef enum _DOT11_RADIO_STATE { 
 dot11_radio_state_unknown, 
 dot11_radio_state_on, 
 dot11_radio_state_off 
} DOT11_RADIO_STATE, *PDOT11_RADIO_STATE;

與前幾個API（好比wlanconnect）比擬，這個函數的應用簡略多了。全體源碼以下：

// ManageWirelessNetwork.cpp : Defines the entry point for the console application. 
// 
 
#include "stdafx.h" 
#include <stdio.h> 
#include <windows.h> 
#include <shellapi.h> 
#include <wlanapi.h> 
 
// Need to link with shell32.lib 
#pragma comment(lib, "shell32.lib") 
#pragma comment(lib, "wlanapi.lib") 
 
int _tmain(int argc, _TCHAR* argv[]) 
{ 
 DWORD dwResult = 0; 
 DWORD dwMaxClient = 2; 
 DWORD dwCurVersion = 0; 
 HANDLE hClient = NULL; 
 PWLAN_INTERFACE_INFO_LIST pIfList = NULL; 
 PWLAN_INTERFACE_INFO pIfInfo = NULL; 
 
 dwResult = WlanOpenHandle(dwMaxClient, NULL, &dwCurVersion, &hClient); 
 if (dwResult != ERROR_SUCCESS) { 
  wprintf(L"WlanOpenHandle failed with error: %u\n", dwResult); 
  return false; 
 } 
 
 dwResult = WlanEnumInterfaces(hClient, NULL, &pIfList); 
 if (dwResult != ERROR_SUCCESS) { 
  wprintf(L"WlanEnumInterfaces failed with error: %u\n", dwResult); 
  return false; 
 } 
  
 WLAN_PHY_RADIO_STATE state; 
 state.dwPhyIndex = 0; 
 state.dot11SoftwareRadioState = dot11_radio_state_on; 
 PVOID pData = &state; 
 
 dwResult = WlanSetInterface(hClient,&pIfList->InterfaceInfo[0].InterfaceGuid, 
  wlan_intf_opcode_radio_state,sizeof(WLAN_PHY_RADIO_STATE),pData,NULL); 
 
 if(dwResult == ERROR_SUCCESS) 
 { 
  wprintf(L"set state success!\n"); 
 } 
 else 
 { 
  wprintf(L"set state failed!err is %d\n",dwResult); 
 } 
 
 return 0; 
}

8.GOTO在釋放資本時的感化
GOTO語句有著很臭的名聲，我們的先生常常教誨我們說，不要隨意馬虎應用它。
C++跳轉語句有三個：goto、break和continue。它們只是對象，我認為成績不克不及歸罪於對象，成績在於人。
就像指針一樣，goto這個無前提跳轉語句力氣照樣很壯大的，假如濫用，湧現成績很難排查。
但有些時刻goto確切是不貳選擇，例如我碰到的，在函數中有多個出口，而每一個出口都碰到釋放資本的時刻，與其都把釋放語句誨人不倦的寫一遍，
不如一個goto語句來的爽性拖拉。
上面的例子取自上一篇Native Wifi API文章，因為我們的法式常常掌握的wifi的on和off，必需留意釋放資本。就拿WlanOpenHandle來講，
假如不留意對稱WlanCloseHandler，法式幾回運轉後報錯：ERROR_REMOTE_SESSION_LIMIT_EXCEEDED
官網說明為：Too many handles have been issued by the server.
所以我們會在每一個API挪用後，確認前往值，假如毛病，法式將不再持續向下運轉，return之前，我們必需釋放資本。當出口許多時，我們要寫許多異樣的代碼，
很焦躁，難讀，代碼急速收縮。但應用goto後，成績便輕松了很多，請看簡略例子：

// ManageWirelessNetwork.cpp : Defines the entry point for the console application. 
// 
 
#include "stdafx.h" 
#include <stdio.h> 
#include <windows.h> 
#include <shellapi.h> 
#include <wlanapi.h> 
 
// Need to link with shell32.lib 
#pragma comment(lib, "shell32.lib") 
#pragma comment(lib, "wlanapi.lib") 
 
int _tmain(int argc, _TCHAR* argv[]) 
{ 
  DWORD dwResult = 0; 
  DWORD dwMaxClient = 2; 
  DWORD dwCurVersion = 0; 
  HANDLE hClient = NULL; 
  PWLAN_INTERFACE_INFO_LIST pIfList = NULL; 
  PWLAN_INTERFACE_INFO pIfInfo = NULL; 
 
  dwResult = WlanOpenHandle(dwMaxClient, NULL, &dwCurVersion, &hClient); 
  if (dwResult != ERROR_SUCCESS) { 
    wprintf(L"WlanOpenHandle failed with error: %u\n", dwResult); 
    return false; 
  } 
 
  dwResult = WlanEnumInterfaces(hClient, NULL, &pIfList); 
  if (dwResult != ERROR_SUCCESS) { 
    wprintf(L"WlanEnumInterfaces failed with error: %u\n", dwResult); 
    goto RELEASE_RESOURCE; 
  } 
   
  WLAN_PHY_RADIO_STATE state; 
  state.dwPhyIndex = 0; 
  state.dot11SoftwareRadioState = dot11_radio_state_on;//off here too. 
  PVOID pData = &state; 
 
  dwResult = WlanSetInterface(hClient,&pIfList->InterfaceInfo[0].InterfaceGuid, 
    wlan_intf_opcode_radio_state,sizeof(WLAN_PHY_RADIO_STATE),pData,NULL); 
 
  if(dwResult == ERROR_SUCCESS) 
  { 
    wprintf(L"set state success!\n"); 
  } 
  else 
  { 
    wprintf(L"set state failed!err is %d\n",dwResult); 
  } 
RELEASE_RESOURCE: 
  if(hClient) 
  { 
    WlanCloseHandle(hClient,NULL); 
    hClient = NULL; 
  } 
  if(pIfList) 
  { 
    WlanFreeMemory(pIfList); 
    pIfList = NULL; 
  } 
  if(pIfInfo) 
  { 
    WlanFreeMemory(pIfInfo); 
    pIfInfo = NULL; 
  } 
  return 0; 
}

最初，goto還會用來跳出多重輪回。但須要留意的是，只能從內層跳到外層，弗成逆操作。

跋文：
其實幾個月前就要完成windows上的wifi on和off，問了很多人，發了很多帖子，最初都不了了之。以後的日子裡也產生了很多事。國際的
搜刮無果，加上谷歌的沒法應用，都對換查增長了些許難度。我們把重點先放到了native wifi api的幾個辦法，見上一篇玩轉文章。但
那其實不是我想要的。
原認為windows也會想android一樣，通俗運用沒有權限來掌握wifi的開關呢，成果其實不是如許。這也宣布了之前我的斷定掉誤。
直到明天，經由過程Bing發明了幾條線索。那是經由過程C#挪用native wifi api的成績，外面說起了之前並沒有看重的wlansetinterface。
Interface，在這裡我認為可以懂得成無線網卡。相似的WlanEnumInterfaces中完成的功效是枚舉出以後無線網卡。
無線網卡的設置，個中有一項是radio的狀況。
果真，這一切都有了了斷。