Android Wifi 控制

//首先取得Wi-Fi服務控制Manager
WifiManager mWifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);

※ Wi-Fi偵測 :
//先判斷是否有開啟Wi-Fi，有開啟則回傳true沒有則回傳false
if(mWifiManager.isWifiEnabled())
{
        //重新掃描Wi-Fi資訊
        mWifiManager.startScan();
        //偵測周圍的Wi-Fi環境(因為會有很多組Wi-Fi，所以型態為List)
        mWifiScanResultList = mWifiManager.getScanResults();
        //手機內已存的Wi-Fi資訊(因為會有很多組Wi-Fi，所以型態為List)
    mWifiConfigurationList = mWifiManager.getConfiguredNetworks();
        //目前已連線的Wi-Fi資訊
        mWifiInfo = mWifiManager.getConnectionInfo();
        
        for(int i = 0 ; i < mWifiScanResultList.size() ; i++ )
        {
             //手機目前周圍的Wi-Fi環境
             SSID (Wi-Fi名稱) = mWifiScanResultList.get(i).SSID ;
             LEVEL (Wi-Fi訊號強弱) = mWifiScanResultList.get(i).level) ;
        }
        
        for(int i = 0 ; i < mWifiConfigurationList.size() ; i++ )
        {
             //手機內已儲存(已連線過)的Wi-Fi資訊
             SSID (Wi-Fi名稱) = mWifiConfigurationList.get(i).SSID ;
             NETWORKID (Wi-Fi連線ID) = mWifiConfigurationList.get(i).networkId ;
        }
        
        //目前手機已連線(現在連線)的Wi-Fi資訊
        SSID (Wi-Fi名稱) = mWifiInfo.getSSID() ;
        NETWORKID (Wi-Fi連線ID) = mWifiInfo.getNetworkId() ;
        IPADRRESS (Wi-Fi連線位置) = mWifiInfo.getIpAddress() ;
        IP (Wi-Fi IP位置) = String.format("%d.%d.%d.%d", (IPADRRESS & 0xff), (IPADRRESS >> 8 & 0xff), (IPADRRESS >> 16 & 0xff),( IPADRRESS >> 24 & 0xff)) ;
}
else 
{
        //把Wi-Fi開啟
        mWifiManager.setWifiEnabled(true);
        Toast.makeText(MainActivity.this, "Wi-Fi開啟中", Toast.LENGTH_SHORT).show();
}

※ Wi-Fi連線 :
//選擇欲連線的Wi-Fi ID帶入即可進行連線
int NETWORKID = 已連線過的Wi-Fi ID ;
mWifiManager.enableNetwork(NETWORKID,true);

※ Wi-Fi中斷 :
//中斷目前的Wi-Fi連線訊號
mWifiManager.disconnect();



source:http://dean-android.blogspot.tw/2013/08/androidwi-fiip.html