我正在开发一个应用程序来检查Wifi点。
我在wifiManager.getScanResults()处收到错误“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));
}
}
表现
<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
我观察到了类似的question,但是由于我已经声明了权限,因此该解决方案不适用。
有人知道可能是什么问题吗?谢谢。
最佳答案
在Android M中,您需要在每次开始使用之前向用户要求在PermissionModel中定义为危险的许可,如下所示:
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 :
private static final int REQUEST_FINE_LOCATION=0
并在运行时使用以下命令加载它:
loadPermissions(Manifest.permission.ACCESS_FINE_LOCATION,REQUEST_FINE_LOCATION);
要评估权限请求的结果,可以重写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;
}
}