找不到附近的 WiFi-Direct 设备，显示“未找到设备！"； [英] Can't find nearby WiFi- Direct devices showing "No Device Found!"
本文介绍了找不到附近的 WiFi-Direct 设备，显示“未找到设备！"；的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在尝试使用 WifiDirect 相互发现两台设备.设备分别运行 Android 8.0 和 9.0 版.但没能成功.
I am trying to Discover two devices each other using WifiDirect. Devices are running Android version 8.0 and 9.0 respectively. But not able to succeed.
我第一次点击两台设备上的发现"按钮时，都会等待 2-3 秒并显示没有找到 Toast 设备.我第二次尝试在一秒钟内发现两者都显示 No device found Toast.
First time I click on Discover button on both devices both waits for 2-3 seconds and shows No device found Toast. Second time I try to discover on both within a second both show up the No device found Toast.
MainActivity.java
package com.example.prototypewfp2p;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import android.Manifest;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.net.wifi.WifiManager;
import android.net.wifi.p2p.WifiP2pDevice;
import android.net.wifi.p2p.WifiP2pDeviceList;
import android.net.wifi.p2p.WifiP2pManager;
import android.os.Build;
import android.os.Bundle;
import android.os.Looper;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.security.Permission;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
Button btnOnOff, btnDiscover, btnSend;
ListView listView;
TextView read_msg_box, ConnectoinStatus;
EditText writeMsg;
WifiManager wifiManager;
WifiP2pManager mMangaer;
WifiP2pManager.Channel mChannel;
BroadcastReceiver mReceiver;
IntentFilter mIntentFilter;
List<WifiP2pDevice> peers = new ArrayList<WifiP2pDevice>();
String[] deviceNameArray;
WifiP2pDevice[] deviceArray;
// Permissions Related
public String[] PermissionsList = {Manifest.permission.CHANGE_WIFI_STATE, Manifest.permission.ACCESS_WIFI_STATE, Manifest.permission.INTERNET, Manifest.permission.ACCESS_NETWORK_STATE
, Manifest.permission.CHANGE_NETWORK_STATE, Manifest.permission.ACCESS_FINE_LOCATION};
public int permsRequestCode = 200;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Permissions
for (int i = 0; i < PermissionsList.length; i++) {
if (ContextCompat.checkSelfPermission(MainActivity.this, PermissionsList[i]) == PackageManager.PERMISSION_DENIED) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(PermissionsList, permsRequestCode);
}
} else {
Toast.makeText(MainActivity.this, "Permissions Granted Already!", Toast.LENGTH_SHORT).show();
}
}
//Calling Functions Declared below
initialWork();
exqListener();
}
//Permission (Override stuff)
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (permsRequestCode) {
case 200:
if(grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
Toast.makeText(this,"Permission[1] granted!",Toast.LENGTH_LONG);
}
else{Toast.makeText(this,"Permission[1] Denied!",Toast.LENGTH_LONG);}
if(grantResults.length > 0 && grantResults[2] == PackageManager.PERMISSION_GRANTED){Log.i("myTag","Permission 3 granted");}
if(grantResults.length > 0 && grantResults[3] == PackageManager.PERMISSION_GRANTED){Log.i("myTag","Permission 4 granted");}
if(grantResults.length > 0 && grantResults[4] == PackageManager.PERMISSION_GRANTED){Log.i("myTag","Permission 5 granted");}
if(grantResults.length > 0 && grantResults[5] == PackageManager.PERMISSION_GRANTED){Log.i("myTag","Permission 6 granted");}
if(grantResults.length > 0 && grantResults[1] == PackageManager.PERMISSION_GRANTED){Log.i("myTag","Permission 2 granted");}
// boolean first = grantResults[0] == PackageManager.PERMISSION_GRANTED;
// boolean second = grantResults[1] == PackageManager.PERMISSION_GRANTED;
// boolean third = grantResults[2] == PackageManager.PERMISSION_GRANTED;
// boolean fourth = grantResults[3] == PackageManager.PERMISSION_GRANTED;
// boolean fifth = grantResults[4] == PackageManager.PERMISSION_GRANTED;
// boolean sixth = grantResults[5] == PackageManager.PERMISSION_GRANTED;
break;
}
}
private void exqListener() {
btnOnOff.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (wifiManager.isWifiEnabled()) {
wifiManager.setWifiEnabled(false);
// Toast.makeText(MainActivity.this,"Wifi is turned OFF",Toast.LENGTH_LONG).show();
} else {
wifiManager.setWifiEnabled(true);
// Toast.makeText(MainActivity.this,"Wifi is turned ON",Toast.LENGTH_LONG).show();
}
}
});
btnDiscover.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION},1);
}
return;
}
mMangaer.discoverPeers(mChannel, new WifiP2pManager.ActionListener() {
@Override
public void onSuccess() {
ConnectoinStatus.setText("Discovery Started!");
}
@Override
public void onFailure(int reason) {
ConnectoinStatus.setText("Could not start Discovery");
}
});
}
});
}
private void initialWork() {
btnOnOff = (Button) findViewById(R.id.onOff);
btnDiscover = (Button) findViewById(R.id.discover);
btnSend = (Button) findViewById(R.id.sendButton);
listView = (ListView) findViewById(R.id.peerListView);
read_msg_box = (TextView) findViewById(R.id.readMsg);
ConnectoinStatus = (TextView) findViewById(R.id.connectionStatus);
writeMsg = (EditText) findViewById(R.id.writeMsg);
wifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
mMangaer = (WifiP2pManager) getSystemService(Context.WIFI_P2P_SERVICE);
mChannel = mMangaer.initialize(this, getMainLooper(),null);
mReceiver = new WiFiDirectBroadcastReciever(mMangaer,mChannel,this);
mIntentFilter = new IntentFilter();
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION);
mIntentFilter.addAction(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
}
WifiP2pManager.PeerListListener peerListListener = new WifiP2pManager.PeerListListener() {
@Override
public void onPeersAvailable(WifiP2pDeviceList peerList) {
if(!peerList.getDeviceList().equals(peers) ){
peers.clear();
peers.addAll(peerList.getDeviceList());
deviceNameArray = new String[peerList.getDeviceList().size()]; //Size of deviceNameArray initialized
deviceArray = new WifiP2pDevice[peerList.getDeviceList().size()]; //Size of deviceArray initialized
int index = 0;
//assigning device name and device to 'deviceNameArray' and 'deviceArray'
for (WifiP2pDevice device: peerList.getDeviceList()){
deviceNameArray[index] = device.deviceName;
deviceArray[index] = device;
index++;
}
ArrayAdapter<String> adapter= new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1,deviceNameArray);
listView.setAdapter(adapter);
}
if(peers.size()==0){
Toast.makeText(MainActivity.this,"No Device Found!",Toast.LENGTH_LONG).show();
return;
}
}
};
@Override
protected void onResume() {
super.onResume();
registerReceiver(mReceiver,mIntentFilter);
}
@Override
protected void onPause() {
super.onPause();
unregisterReceiver(mReceiver);
}
}
WiFiDirectBroadcastReciever.java
package com.example.prototypewfp2p;
import android.Manifest;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.wifi.WifiManager;
import android.net.wifi.p2p.WifiP2pManager;
import android.widget.Toast;
import androidx.core.app.ActivityCompat;
import static android.media.audiofx.Visualizer.STATE_ENABLED;
public class WiFiDirectBroadcastReciever extends BroadcastReceiver {
private WifiP2pManager mMangaer;
private WifiP2pManager.Channel mChannel;
private MainActivity mActivity;
public WiFiDirectBroadcastReciever(WifiP2pManager mMangaer, WifiP2pManager.Channel mChannel, MainActivity mActivity) {
this.mMangaer = mMangaer;
this.mActivity = mActivity;
this.mChannel = mChannel;
}
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (WifiP2pManager.WIFI_P2P_STATE_CHANGED_ACTION.equals(action)) {
int state = intent.getIntExtra(WifiP2pManager.EXTRA_WIFI_STATE, -1);
if (state == WifiP2pManager.WIFI_P2P_STATE_ENABLED) {
Toast.makeText(context, "Wifi is On", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(context, "Wifi is Off", Toast.LENGTH_SHORT).show();
}
} else if (WifiP2pManager.WIFI_P2P_PEERS_CHANGED_ACTION.equals(action)) {
if (mMangaer != null) {
if (ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
Toast.makeText(context,"Acces Location (BroadcastRec) Not granted",Toast.LENGTH_SHORT).show();
}
mMangaer.requestPeers(mChannel, mActivity.peerListListener);
}
}
else if(WifiP2pManager.WIFI_P2P_CONNECTION_CHANGED_ACTION.equals(action)){
}
else if(WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action)){
}
}
}
activitymain.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="@+id/onOff"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginStart="24dp"
android:layout_marginTop="47dp"
android:text="Wifi On/Off"
android:textSize="13dp" />
<Button
android:id="@+id/discover"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/onOff"
android:layout_alignBottom="@+id/onOff"
android:layout_centerHorizontal="true"
android:layout_marginBottom="3dp"
android:layout_marginLeft="0dp"
android:text="discover" />
<ListView
android:id="@+id/peerListView"
android:layout_width="match_parent"
android:layout_height="200dp"
android:layout_alignParentStart="true"
android:layout_below="@+id/onOff"
android:layout_marginTop="25dp"
android:background="@android:color/holo_orange_light" />
<TextView
android:id="@+id/readMsg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentStart="true"
android:layout_below="@+id/peerListView"
android:layout_marginTop="31dp"
android:text="Message"
android:textAlignment="center"
android:textSize="20sp"
android:textStyle="italic" />
<EditText
android:id="@+id/writeMsg"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentStart="true"
android:ems="10"
android:inputType="textPersonName"
android:layout_toStartOf="@+id/sendButton" />
<Button
android:id="@+id/sendButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:text="Send" />
<TextView
android:id="@+id/connectionStatus"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_marginTop="15dp"
android:text="Connection Status"
android:textAlignment="center"
android:textColor="@android:color/holo_blue_dark"
android:textSize="18sp"
android:textStyle="italic" />
</RelativeLayout>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.prototypewfp2p">
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/Theme.Prototypewfp2p">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
推荐答案
IDK 为什么 但是您必须在两台设备上都启用 gps(位置).我还使用 android 8 版设备和 android 10 设备 gps 进行了测试，两者都运行良好.
IDK why But you have to enable gps (Location) on both devices. I have also tested with android version 8 device and android 10 device gps enabled Both are working perfectly fine.
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