Android WifiManager getScanResult complains Need ACCESS_COARSE_LOCATION or ACCESS_FINE_LOCATION permission although declared permission

I am developing an App to check Wifi points.

I am getting error "java.lang.SecurityException: Need ACCESS_COARSE_LOCATION or ACCESS_FINE_LOCATION permission to get scan results" at wifiManager.getScanResults() even though I already declared those permissions.

main activity

public class MainActivity extends AppCompatActivity {

WifiManager wifiManager;
String[] wifis;
WifiReceiver wifiReceiver;

ListView wifiListView;

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

    wifiListView = (ListView) findViewById(R.id.wifi_list);

    wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
    wifiReceiver = new WifiReceiver();
    wifiManager.startScan();
}

protected void onPause() {
    unregisterReceiver(wifiReceiver);
    super.onPause();
}

protected void onResume() {
    registerReceiver(wifiReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
    super.onResume();
}

private class WifiReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        List<ScanResult> wifiScanList = wifiManager.getScanResults();
        wifis = new String[wifiScanList.size()];

        for (int i = 0; i < wifiScanList.size(); i++) {
            wifis[i] = wifiScanList.get(i).toString();
        }

        wifiListView.setAdapter(new ArrayAdapter<>(getApplicationContext(), android.R.layout.simple_list_item_1, wifis));
    }
}

manifest

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.sample">

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<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_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

<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>
</application>

I am on SDK 6.0

I observed similar question, but solution does not apply since I already declared permission.

Anyone know what might be problem? Thank you.

In Android M, you need to ask for the permission which is defined as dangerous in PermissionModel to the user before start using each time, it as such:

private boolean mayRequestLocation() {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
            return true;
        }
        if (checkSelfPermission(ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
            return true;
        }
        if (shouldShowRequestPermissionRationale(ACCESS_FINE_LOCATION)) {
            Snackbar.make(mView, R.string.permission_rationale, Snackbar.LENGTH_INDEFINITE)
                    .setAction(android.R.string.ok, new View.OnClickListener() {
                        @Override
                        @TargetApi(Build.VERSION_CODES.M)
                        public void onClick(View v) {
                            requestPermissions(new String[]{ACCESS_FINE_LOCATION}, REQUEST_FINE_LOCATION);
                        }
                    });
        } else {
            requestPermissions(new String[]{ACCESS_FINE_LOCATION}, REQUEST_FINE_LOCATION);
        }
        return false;
    }

Add this to your Activity:

private static final int REQUEST_FINE_LOCATION=0

and load it during runtime with:

loadPermissions(Manifest.permission.ACCESS_FINE_LOCATION,REQUEST_FINE_LOCATION);

To evaluate the results of your permission request, you can override onRequestPermissionsResult method:

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    switch (requestCode) {
        case REQUEST_FINE_LOCATION: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // The requested permission is granted.
            }
            else{
                // The user disallowed the requested permission.
            }
            return;
        }

}

Antonios Vortis

MADAO is right: you should turn on GPS to get the WIFI access point list.

But I'm not sure about PEERS_MAC_ADDRESS. If you look at the source code (line 957):

/**
 * Return the results of the most recent access point scan, in the form of
 * a list of {@link ScanResult} objects.
 * @return the list of results
 */
public List<ScanResult> getScanResults(String callingPackage) {
    enforceAccessPermission();
    int userId = UserHandle.getCallingUserId();
    int uid = Binder.getCallingUid();
    boolean canReadPeerMacAddresses = checkPeersMacAddress();
    boolean isActiveNetworkScorer =
            NetworkScorerAppManager.isCallerActiveScorer(mContext, uid);
    boolean hasInteractUsersFull = checkInteractAcrossUsersFull();
    long ident = Binder.clearCallingIdentity();
    try {
        if (!canReadPeerMacAddresses && !isActiveNetworkScorer
                && !isLocationEnabled()) {
            return new ArrayList<ScanResult>();
        }
        if (!canReadPeerMacAddresses && !isActiveNetworkScorer
                && !checkCallerCanAccessScanResults(callingPackage, uid)) {
            return new ArrayList<ScanResult>();
        }
        if (mAppOps.noteOp(AppOpsManager.OP_WIFI_SCAN, uid, callingPackage)
                != AppOpsManager.MODE_ALLOWED) {
            return new ArrayList<ScanResult>();
        }
        if (!isCurrentProfile(userId) && !hasInteractUsersFull) {
            return new ArrayList<ScanResult>();
        }
        return mWifiStateMachine.syncGetScanResultsList();
    } finally {
        Binder.restoreCallingIdentity(ident);
    }
}

The first if is checking canReadPeerMacAddresses which the code for checkPeersMacAddress() is:

/**
 * Returns true if the caller holds PEERS_MAC_ADDRESS.
 */
private boolean checkPeersMacAddress() {
    return mContext.checkCallingOrSelfPermission(
            android.Manifest.permission.PEERS_MAC_ADDRESS) == PackageManager.PERMISSION_GRANTED;
}

If you add the permission you can bypass if (!canReadPeerMacAddresses && !isActiveNetworkScorer && !isLocationEnabled()) {. I've tested but I cannot get WIFI MAC list by just using the permission and disabling location.

MADAO

ACCESS_FINE_LOCATION or ACCESS_COARSE_LOCATION is necessary. To get a valid result, you also have to turn on GPS or get a PEERS_MAC_ADDRESS permission like Setting.

来源：https://stackoverflow.com/questions/33730781/android-wifimanager-getscanresult-complains-need-access-coarse-location-or-acces

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