问题
I'm having this problem on some 2013 Nexus 7's.
got some code to work (please see below).
package acme.wifi;
import android.content.*;
import android.net.wifi.*;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import java.math.*;
import java.net.*;
import java.nio.*;
import java.util.*;
public class MainActivity extends AppCompatActivity {
void retry() {
WifiManager wifiMan=(WifiManager)getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInf;
int ipAddress;
List<WifiConfiguration> wifiConfigurations=wifiMan.getConfiguredNetworks();
System.out.println("wifi configurations (all): "+wifiConfigurations.size());
for(WifiConfiguration wifiConfiguration : wifiConfigurations) {
if(wifiConfiguration.toString().contains("192.168.0.")) {
System.out.println("found our network: "+wifiConfiguration.toString());
System.out.println("SSID: "+wifiConfiguration.SSID);
System.out.println("wifi configuration status is disabled: "+(wifiConfiguration.status==WifiConfiguration.Status.DISABLED));
int networkId=wifiConfiguration.networkId;
boolean ok=wifiMan.disconnect();
System.out.println("disconnect() returns: "+ok);
System.out.println("enabling our network: "+networkId);
// https://code.google.com/p/android-developer-preview/issues/detail?id=2218
ok=wifiMan.enableNetwork(networkId,true);
System.out.println("enableNetwork() returns: "+ok);
System.out.println("trying to recommect to wifi.");
ok=wifiMan.reconnect();
System.out.println("reconnect returns: "+ok);
if(ok) {
wifiMan=(WifiManager)getSystemService(Context.WIFI_SERVICE);
wifiInf=wifiMan.getConnectionInfo();
ipAddress=wifiInf.getIpAddress();
System.out.println("wifi ip adress: "+ipAddress);
}
break;
}
}
}
String getIpAddressFromWifiManager() {
WifiManager wifiMan=(WifiManager)getSystemService(Context.WIFI_SERVICE);
System.out.println("isWifiEnabled() returns: "+wifiMan.isWifiEnabled());
WifiInfo wifiInf=wifiMan.getConnectionInfo();
System.out.println("wifi info: "+wifiInf);
int ipAddress=wifiInf.getIpAddress();
System.out.println("wifi ip adress: "+ipAddress);
if(ByteOrder.nativeOrder().equals(ByteOrder.LITTLE_ENDIAN))
ipAddress=Integer.reverseBytes(ipAddress);
byte[] ipByteArray=BigInteger.valueOf(ipAddress).toByteArray();
String ipAddressString=null;
try {
ipAddressString=InetAddress.getByAddress(ipByteArray).getHostAddress();
} catch(UnknownHostException ex) {
System.out.println("Unable to get host address.");
if(true)
retry();
}
return ipAddressString;
}
public class W extends Thread {
W(int sleep) {
this.sleep=sleep;
}
@Override public void run() {
try {
Thread.sleep(sleep);
} catch(InterruptedException e) {
System.out.println("1 caught: "+e);
}
String ipAddress=getIpAddressFromWifiManager();
System.out.println("ip address: "+ipAddress);
if(ipAddress==null)
new W(5_000).start();
}
int sleep;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar=(Toolbar)findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab=(FloatingActionButton)findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view,"Replace with your own action",Snackbar.LENGTH_LONG).setAction("Action",null).show();
}
});
new W(0).start();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main,menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id=item.getItemId();
//noinspection SimplifiableIfStatement
if(id==R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
02-22 19:41:08.637 2715-2734/? I/System.out: isWifiEnabled() returns: true
02-22 19:41:08.638 2715-2734/? I/System.out: wifi info: SSID: , BSSID: 00:00:00:00:00:00, MAC: 02:00:00:00:00:00, Supplicant state: SCANNING, RSSI: -127, Link speed: -1Mbps, Frequency: -1MHz, Net ID: -1, Metered hint: false, score: 0
02-22 19:41:08.638 2715-2734/? I/System.out: wifi ip adress: 0
02-22 19:41:08.638 2715-2734/? I/System.out: Unable to get host address.
02-22 19:41:08.644 2715-2734/? I/System.out: wifi configurations (all): 1
02-22 19:41:08.646 2715-2734/? I/System.out: found our network: ID: 0 SSID: "tablets" PROVIDER-NAME: null BSSID: null FQDN: null PRIO: 2
02-22 19:41:08.646 2715-2734/? I/System.out: numAssociation 74
02-22 19:41:08.646 2715-2734/? I/System.out: numNoInternetAccessReports 11
02-22 19:41:08.646 2715-2734/? I/System.out: KeyMgmt: NONE Protocols: WPA RSN
02-22 19:41:08.647 2715-2734/? I/System.out: AuthAlgorithms: OPEN SHARED
02-22 19:41:08.647 2715-2734/? I/System.out: PairwiseCiphers: TKIP CCMP
02-22 19:41:08.647 2715-2734/? I/System.out: GroupCiphers: TKIP CCMP
02-22 19:41:08.647 2715-2734/? I/System.out: PSK:
02-22 19:41:08.647 2715-2734/? I/System.out: Enterprise config:
02-22 19:41:08.647 2715-2734/? I/System.out: password NULL
02-22 19:41:08.647 2715-2734/? I/System.out: engine 0
02-22 19:41:08.647 2715-2734/? I/System.out: client_cert NULL
02-22 19:41:08.647 2715-2734/? I/System.out: anonymous_identity NULL
02-22 19:41:08.647 2715-2734/? I/System.out: identity NULL
02-22 19:41:08.647 2715-2734/? I/System.out: domain_suffix_match NULL
02-22 19:41:08.647 2715-2734/? I/System.out: phase2 NULL
02-22 19:41:08.647 2715-2734/? I/System.out: altsubject_match NULL
02-22 19:41:08.647 2715-2734/? I/System.out: subject_match NULL
02-22 19:41:08.647 2715-2734/? I/System.out: ca_cert NULL
02-22 19:41:08.647 2715-2734/? I/System.out: phase1 NULL
02-22 19:41:08.647 2715-2734/? I/System.out: key_id NULL
02-22 19:41:08.647 2715-2734/? I/System.out: engine_id NULL
02-22 19:41:08.647 2715-2734/? I/System.out: eap NULL
02-22 19:41:08.647 2715-2734/? I/System.out: IP config:
02-22 19:41:08.647 2715-2734/? I/System.out: IP assignment: STATIC
02-22 19:41:08.647 2715-2734/? I/System.out: Static configuration: IP address 192.168.0.11/24 Gateway 192.168.0.1 DNS servers: [ 8.8.8.8 ] Domains
02-22 19:41:08.647 2715-2734/? I/System.out: Proxy settings: NONE
02-22 19:41:08.647 2715-2734/? I/System.out: cuid=1000 cname=android.uid.system:1000 luid=1000 lname=android.uid.system:1000 lcuid=10044 userApproved=USER_APPROVED noInternetAccessExpected=false roamingFailureBlackListTimeMilli: 1000
02-22 19:41:08.647 2715-2734/? I/System.out: triggeredLow: 0 triggeredBad: 0 triggeredNotHigh: 0
02-22 19:41:08.647 2715-2734/? I/System.out: ticksLow: 0 ticksBad: 0 ticksNotHigh: 0
02-22 19:41:08.647 2715-2734/? I/System.out: triggeredJoin: 0
02-22 19:41:08.648 2715-2734/? I/System.out: autoJoinBailedDueToLowRssi: false
02-22 19:41:08.648 2715-2734/? I/System.out: autoJoinUseAggressiveJoinAttemptThreshold: 0
02-22 19:41:08.648 2715-2734/? I/System.out: SSID: "tablets"
02-22 19:41:08.648 2715-2734/? I/System.out: wifi configuration status is disabled: false
02-22 19:41:08.649 2715-2734/? I/System.out: disconnect() returns: true
02-22 19:41:08.649 2715-2734/? I/System.out: enabling our network: 0
02-22 19:41:08.738 2715-2734/? I/System.out: enableNetwork() returns: true
02-22 19:41:08.738 2715-2734/? I/System.out: trying to recommect to wifi.
02-22 19:41:08.739 2715-2734/? I/System.out: reconnect returns: true
02-22 19:41:08.740 2715-2734/? I/System.out: wifi ip adress: 0
02-22 19:41:08.740 2715-2734/? I/System.out: ip address: null
02-22 19:41:13.744 2715-2741/? I/System.out: isWifiEnabled() returns: true
02-22 19:41:13.747 2715-2741/? I/System.out: wifi info: SSID: tablets, BSSID: 60:e3:27:fb:8d:5a, MAC: 02:00:00:00:00:00, Supplicant state: COMPLETED, RSSI: -40, Link speed: 54Mbps, Frequency: 2462MHz, Net ID: 0, Metered hint: false, score: 60
02-22 19:41:13.747 2715-2741/? I/System.out: wifi ip adress: 184592576
02-22 19:41:13.748 2715-2741/? I/System.out: ip address: 192.168.0.11
回答1:
I was facing the same problem, but I have solved it.
Add these permissions:
android.permission.ACCESS_FINE_LOCATIONandroid.permission.ACCESS_COARSE_LOCATION
and Keep Location Service ON.
Strange but true.
回答2:
I have same issue with 5.1.1 and Try to ping server of google.com like:
public Boolean isOnline() {
try {
// Process p1 = runtime.exec("/system/bin/ping -c 1 8.8.8.8");
Process p1 = java.lang.Runtime.getRuntime().exec("ping -c 1 www.google.com");
int returnVal = p1.waitFor();
boolean reachable = (returnVal==0);
return reachable;
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return false;
}
this will give you correct response.
回答3:
I think need to add Network State Access permission in AndroidManifest.xml
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
回答4:
Add permission in the manifest file:
android.permission.ACCESS_FINE_LOCATIONandroid.permission.ACCESS_COARSE_LOCATION- Turn on Location Service
回答5:
The new code in the question seems to work.
4/16 now the code has stopped working :(
来源：https://stackoverflow.com/questions/35282807/android-studio-1-5-1-marshmallow-no-internet-access-detected-wont-automaticall