android11上wifi开发完整案例

以下是一个在Android 11上的WiFi开发完整案例：

1. Manifest文件配置权限和服务。

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

<service
    android:name="com.example.wifiservice.WifiService"
    android:enabled="true"
    android:exported="false"/>

2. 创建Service类，实现WifiManager的各种相关操作。其中需要注意的是，在Android 11及以上版本，通过WifiManager获取到的Wifi信息已经不再包含SSID等敏感信息，需要通过registerNetworkCallback或者扫描接口获取到。

public class WifiService extends Service {

    private final String TAG = WifiService.class.getSimpleName();

    private WifiManager wifiManager;

    private Context context;

    private WifiScanResultListener scanResultListener;

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();

        Log.d(TAG, "WifiService onCreate");

        wifiManager = (WifiManager) this.getApplicationContext().getSystemService(Context.WIFI_SERVICE);

        context = this.getApplicationContext();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d(TAG, "WifiService onStartCommand");

        if (intent != null) {

            String action = intent.getAction();

            if (action != null && action.equals("start_scan")) {

                startScan();

            }

        }

        return START_STICKY;
    }

    /**
     * 开始扫描Wifi
     */
    private void startScan() {

        wifiManager.startScan();

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {

            registerNetworkCallback();

        } else {

            scanResultListener = new WifiScanResultListener();

            IntentFilter filter = new IntentFilter();

            filter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);

            context.registerReceiver(scanResultListener, filter);

        }
    }

    /**
     * Android 11及以上版本通过registerNetworkCallback获取Wifi信息
     */
    @RequiresApi(api = Build.VERSION_CODES.R)
    private void registerNetworkCallback() {

        NetworkRequest.Builder builder = new NetworkRequest.Builder();

        builder.addTransportType(NetworkCapabilities.TRANSPORT_WIFI);

        final ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

        if (connectivityManager != null) {

            connectivityManager.registerNetworkCallback(builder.build(),

                    new ConnectivityManager.NetworkCallback() {

                        @Override
                        public void onAvailable(Network network) {

                            Log.d(TAG, "onAvailable network=" + network);

                            List<ScanResult> scanResults = wifiManager.getScanResults();

                            if (scanResults != null && scanResults.size() > 0) {

                                for (ScanResult scanResult : scanResults) {

                                    Log.d(TAG, "onAvailable scanResult=" + scanResult.toString());

                                }

                            }

                        }

                    });

        }

    }

    /**
     * Android 11以下版本通过扫描接口获取Wifi信息
     */
    private class WifiScanResultListener extends BroadcastReceiver {

        @Override
        public void onReceive(Context context, Intent intent) {

            String action = intent.getAction();

            if (action != null && action.equals(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)) {

                List<ScanResult> scanResults = wifiManager.getScanResults();

                if (scanResults != null && scanResults.size() > 0) {

                    for (ScanResult scanResult : scanResults) {

                        Log.d(TAG, "onReceive scanResult=" + scanResult.toString());

                    }

                }

            }

        }
    }

}

3. 在Activity中控制Service的开启和关闭。

public class MainActivity extends AppCompatActivity {

    private Button btnStart, btnStop;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btnStart = findViewById(R.id.btn_start);
        btnStop = findViewById(R.id.btn_stop);

        btnStart.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                Intent intent = new Intent(MainActivity.this, WifiService.class);

                intent.setAction("start_scan");

                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

                    startForegroundService(intent);

                } else {

                    startService(intent);

                }

            }

        });

        btnStop.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                Intent intent = new Intent(MainActivity.this, WifiService.class);

                stopService(intent);

            }

        });

    }

}

以上就是一个在Android 11上的WiFi开发完整案例，通过使用Service和WifiManager，实现了对WiFi的扫描和获取WiFi信息的功能，并根据不同Android版本做了不同的处理。