Android WifiManager getScanResult抱怨需要ACCESS_COARSE_LOCATION或ACCESS_FINE_LOCATION权限，尽管已声明权限 [英] Android WifiManager getScanResult complains Need ACCESS_COARSE_LOCATION or ACCESS_FINE_LOCATION permission although declared permission

问题描述

我正在开发一个用于检查Wifi点的应用程序.

I am developing an App to check Wifi points.

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

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.

主要活动

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));
    }
}

清单

<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>

我在使用SDK 6.0

I am on SDK 6.0

我观察到类似的问题，但是由于我已经解决了，所以解决方案不适用宣布允许.

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

有人知道可能是什么问题吗?谢谢.

Anyone know what might be problem? Thank you.

推荐答案

在Android M中，您需要在每次使用前向用户要求PermissionModel中定义为危险的权限，例如:

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;
    }

将此添加到您的活动中:

Add this to your Activity:

private static final int REQUEST_FINE_LOCATION=0

并在运行时使用以下命令加载它:

and load it during runtime with:

loadPermissions(Manifest.permission.ACCESS_FINE_LOCATION,REQUEST_FINE_LOCATION);

要评估权限请求的结果，可以覆盖onRequestPermissionsResult方法:

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;
        }

}

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