Android Practice – Android Wi-Fi direct connection

Android wi-fi directly connected

Wi-fi direct connection is a new feature added in Android 4.0(API Level 14) or later. You can use the Wi-Fi direct connection related API to discover and connect to devices that support Wi-Fi direct connection. After the connection, devices can communicate with each other over a much longer distance than bluetooth

Summary of the API

• Wi-fi direct connection method
  
  classWifiP2pManagerProvides methods to discover connected devices using associated interfaces for Wi-Fi direct connection

• Wi-fi connection monitoring
  
  classWifiP2pManagerAlso provides a lot of listening interfaces, timing notifications of the currentactivityRelated to searching and linking
  
  The results of

• Wi-fi directly connectedIntent

Create an application for direct Wi-Fi connection

• Initialization Settings

  First of all, make sure to set up the protocol to support wi-fi direct connection. If so, we can get an instance of WifiP2pManager, create and register the related broadcast. Android :minSdkVersion=”14″ Android :minSdkVersion=”14″

  <uses-sdk android:minSdkVersion="14" />
  <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
  <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
  <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
  <uses-permission android:name="android.permission.INTERNET" />
  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />Copy the code

• Initialize the WifiP2pManager instance and register the related broadcasts to listen for wi-fi direct connection status

  private WifiP2pManager mManager;
  private Channel mChannel;
  private IntentFilter directFilter;
  private WiFiDirectReceiver directReceiver ;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
  
    mManager = (WifiP2pManager)this.getSystemService(Context.WIFI_P2P_SERVICE);
    mChannel = mManager.initialize(this.this.getMainLooper(), null);
    directReceiver = new WiFiDirectReceiver(mManager, mChannel, this);
  
    directFilter = new IntentFilter();
    directFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
    directFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
    directFilter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
    directFilter.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
  
  }
  
  // Register a broadcast listener
  @Override
  protected void onResume(a) {
    super.onResume();
    this.registerReceiver(directReceiver, directFilter);
  }
  
  // Cancel registration
  @Override
  protected void onPause(a) {
    super.onPause();
    this.unregisterReceiver(directReceiver);
  }Copy the code

Radio and accept

  public class WiFiDirectReceiver extends BroadcastReceiver{

      private WifiP2pManager mManager;
      private Channel mChannel;
      private MainActivity mActivity;
      private PeerListListener mListener;
      private WifiP2pConfig mConfig = new WifiP2pConfig();

      public WiFiDirectReceiver(){}

      public WiFiDirectReceiver(WifiP2pManager manager,Channel channel,MainActivity activity){
          this.mManager = manager;
          this.mChannel = channel;
          this.mActivity = activity;

      }

      @Override
      public void onReceive(Context context, Intent intent) {
          String action = intent.getAction();
          Log.e("tag"."===============wifi direct action: "+action);
          if(action.equals(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION)){
              int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, - 1);
              if(state == WifiP2pManager.WIFI_P2P_STATE_ENABLED){
                  / / open
              }else if(state == WifiP2pManager.WIFI_P2P_STATE_DISABLED){
                  / / close}}else if(action.equals(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION)){}else if(action.equals(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION)){}else if(action.equals(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION)){}}}Copy the code

• Find equipment

  Wifip2pmanager.wifi_p2p_state_changed_action is broadcast after the initialize() method is called. If the status of WifiP2pManager.WIFI_P2P_STATE_ENABLED is enabled, call the discoverPeers method in BroadcastReceiver, and call the onSuccess method if the device is found

  mManager.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
  @Override
                      public void onSuccess(a) {
                          Log.e("tag"."===================discovery success");
                      }
  
                      @Override
                      public void onFailure(int reason) {
                          Log.e("tag"."===================discovery failed"); }});Copy the code

  Wifip2pmanager. WIFI_P2P_PEERS_CHANGED_ACTION if a device is found, the system fires the broadcast wifiP2pManager. WIFI_P2P_PEERS_CHANGED_ACTION, in which the requestPeers method is called to list all devices

  if(null! = mManager){ mManager.requestPeers(mChannel,new WifiP2pManager.PeerListListener() {
  
                  @Override
                  public void onPeersAvailable(WifiP2pDeviceList peers) {
                      Log.e("tag"."==================peers list size: "+peers.getDeviceList().size());
                      for(WifiP2pDevice device: peers.getDeviceList()){
                          Log.e("tag"."==================device addr: "+device.deviceName+" name: "+device.deviceName); }}}); }Copy the code

• Connected devices

  For discovered devices we can call the connect() method to connect. We need to initialize WifiP2pConfig and set the deviceAddress of config

  private WifiP2pConfig mConfig = new WifiP2pConfig();  
  mConfig.deviceAddress = device.deviceAddress;
                          mManager.connect(mChannel, mConfig, new WifiP2pManager.ActionListener() {
                              @Override
                              public void onSuccess(a) {
                                  Log.e("tag"."==============connnect success");
                              }
  
                              @Override
                              public void onFailure(int reason) {
                                  Log.e("tag"."=================connect failed"); }});Copy the code

  A successful connection is called back to the onSuccess method

  Data transmission to be continued…