未收到扫描结果

Question

我不知道我做错了什么。我已经注册了 BroadcastReceiver。我定期调用 onReceive，但 WifiManager 的扫描结果为 0。

当我将 wifi 状态打印到日志中时，它总是变得 WIFI_STATE_UNKNOWN。当我检查 wifi 设置中的结果时，我有很多扫描结果。我什至连接到一个。

接收者：

public class NetworkManager extends BroadcastReceiver {
private final static String TAG = NetworkManager.class.getSimpleName();

private WifiManager access;

private static NetworkManager manager;
private List<WifiScanCallback> callbackList;

public static NetworkManager getManager(Context context) {
    if (manager == null) {
        manager = new NetworkManager();
        manager.init(context);
    }

    return manager;
}

public void init(Context context){
    access = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
    callbackList = new ArrayList<>();
}

public NetworkManager() {
    manager = this;
}

@Override
public void onReceive(Context context, Intent intent) {
    int wifiState = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, WifiManager.WIFI_STATE_UNKNOWN);
    Log.d(TAG, "onReceive: "+intent);
    debugWifiState(wifiState);
    if(!isAccessNull()){
        List<ScanResult> result = access.getScanResults();
        if(callbackList != null && result != null && result.size() > 0 && callbackList.size() > 0){
            for(ScanResult currResult : result){
                Log.d(TAG, "onReceive: "+currResult.SSID);
                for(WifiScanCallback callback : callbackList){
                    String ssid = currResult.SSID;
                    callback.onResult(ssid, null);
                }
            }

        }
    }
    scan(true);
}
}

主要活动

@Override
protected void onResume() {
    super.onResume();
    networkManager = NetworkManager.getManager(this);

    IntentFilter filter = new IntentFilter();
    filter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
    registerReceiver(networkManager, filter);

    networkManager.scan(true);
}

清单

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

Answer 1

从 Android 6.0 开始，您必须在运行时请求权限，这个答案对我有帮助：

未收到扫描结果

No scan results received

android

android-wifi

wifimanager