java - Android WifiManager getScanResult 提示需要 ACCESS_COARSE_LOCATION 或 ACCESS_FINE_LOCATION 权限，尽管已声明权限

Question

我正在开发一个应用程序来检查 Wifi 热点。

我在 wifiManager.getScanResults() 收到错误“java.lang.SecurityException:需要 ACCESS_COARSE_LOCATION 或 ACCESS_FINE_LOCATION 权限才能获取扫描结果”，即使我已经声明了这些权限。

主要 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));
    }
}

list

<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>

我在 SDK 6.0 上

我观察到类似的question ，但解决方案不适用，因为我已经声明许可。

谁知道可能是什么问题？谢谢。

Answer 1

在Android M中，每次开始使用前都需要向用户请求PermissionModel中定义为危险的权限，是这样的:

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;
    }

将此添加到您的 Activity 中:

private static final int REQUEST_FINE_LOCATION=0

并在运行时加载它:

loadPermissions(Manifest.permission.ACCESS_FINE_LOCATION,REQUEST_FINE_LOCATION);

要评估您的权限请求的结果，您可以覆盖 onRequestPermissionsResult 方法:

@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;
        }

}