如何将Android Wifi扫描结果放入列表中？

Question

我知道如何获取Android Wifi扫描的<List>，但我无法找出将它们制作成列表适配器的最佳方法。我希望能够将扫描的SSID和BSSID绑定到text1和text2上。

我所尝试的示例：

wifi.startScan();
        // get list of the results in object format ( like an array )
        List<ScanResult> results = wifi.getScanResults();`

        // loop that goes through list
        for (ScanResult result : results) {
            Toast.makeText(this, result.SSID + " " + result.level,
                    Toast.LENGTH_SHORT).show();

而且：

private void fillDataFromDb() {
        Cursor scanCursor = Db.fetchAllScans();
        startManagingCursor(scanCursor);`

        // Create an array to specify the fields we want to display in the list
        // (only TITLE)
        String[] from = new String[] { WifiDbAdapter.KEY_BSSID,
                WifiDbAdapter.KEY_SSID };

        // and an array of the fields we want to bind those fields to (in this
        // case just text1)
        int[] to = new int[] { R.id.text1, R.id.text2 };

        // Now create a simple cursor adapter and set it to display
        SimpleCursorAdapter scansdb = new SimpleCursorAdapter(this,
                R.layout.scan_row, scanCursor, from, to);
        setListAdapter(scansdb);
    }

- Seth Hikari

---

我也想看看你的代码。你是否得到了这样的结果？：List<ScanResult> results = wifi.getScanResults(); - eternalmatt

我已经在做这个，只是为了得到Toast消息：wifi.startScan(); // 以对象格式（类似于数组）获取结果列表 List results = wifi.getScanResults(); // 循环遍历列表 for (ScanResult result : results) { Toast.makeText(this, result.SSID + " " + result.level, Toast.LENGTH_SHORT).show(); - Seth Hikari

@eternalmatt 是的，那正是我得到结果的方式，而且效果很好，只是不知道如何将其绑定到列表视图。 - Seth Hikari

Answer 1

尝试运行这段代码

public class WiFiDemo extends Activity implements OnClickListener
 {      
    WifiManager wifi;       
    ListView lv;
    TextView textStatus;
    Button buttonScan;
    int size = 0;
    List<ScanResult> results;

    String ITEM_KEY = "key";
    ArrayList<HashMap<String, String>> arraylist = new ArrayList<HashMap<String, String>>();
    SimpleAdapter adapter;

    /* Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        textStatus = (TextView) findViewById(R.id.textStatus);
        buttonScan = (Button) findViewById(R.id.buttonScan);
        buttonScan.setOnClickListener(this);
        lv = (ListView)findViewById(R.id.list);

        wifi = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        if (wifi.isWifiEnabled() == false)
        {
            Toast.makeText(getApplicationContext(), "wifi is disabled..making it enabled", Toast.LENGTH_LONG).show();
            wifi.setWifiEnabled(true);
        }   
        this.adapter = new SimpleAdapter(WiFiDemo.this, arraylist, R.layout.row, new String[] { ITEM_KEY }, new int[] { R.id.list_value });
        lv.setAdapter(this.adapter);

        registerReceiver(new BroadcastReceiver()
        {
            @Override
            public void onReceive(Context c, Intent intent) 
            {
               results = wifi.getScanResults();
               size = results.size();
            }
        }, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));                    
    }

    public void onClick(View view) 
    {
        arraylist.clear();          
        wifi.startScan();

        Toast.makeText(this, "Scanning...." + size, Toast.LENGTH_SHORT).show();
        try 
        {
            size = size - 1;
            while (size >= 0) 
            {   
                HashMap<String, String> item = new HashMap<String, String>();                       
                item.put(ITEM_KEY, results.get(size).SSID + "  " + results.get(size).capabilities);

                arraylist.add(item);
                size--;
                adapter.notifyDataSetChanged();                 
            } 
        }
        catch (Exception e)
        { }         
    }    
}

WiFiDemo.xml :

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="16dp"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_vertical"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/textStatus"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Status" />

        <Button
            android:id="@+id/buttonScan"
            android:layout_width="wrap_content"
            android:layout_height="40dp"
            android:text="Scan" />
    </LinearLayout>

    <ListView
        android:id="@+id/list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="20dp"></ListView>
</LinearLayout>

针对ListView- row.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="8dp">

    <TextView
        android:id="@+id/list_value"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="14dp" />
</LinearLayout>

在AndroidManifest.xml中添加这些权限。

<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" />

- Anshul

---

注销广播接收器怎么样？ - bk138

textStatus 是无用的。 - Beyondo

谢谢您提供这段代码。我该如何在列表中持续扫描Wifi并返回RSS值？ - Reyha

Answer 2

除了接受的答案之外，您还需要在AndroidManifest中添加以下权限才能使其正常工作：

 <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
 <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" /> 

- Carlos

Answer 3

将List<ScanResult>包装在ArrayAdapter中。重写getView()方法以使用ScanResult数据填充行。这里是我一本书的免费节选，介绍如何创建类似此类自定义ArrayAdapters。

- CommonsWare

---

你能给我演示一下这道题吗？ - Nirav Ranpara

这本书看起来不错。谢谢。 - Robin

Answer 4

以下是完整的工作示例：

以下是@Android的代码，非常好，但存在一些问题，即：

1. ListView填充代码需要移动到BroadCastReceiver的onReceive方法中，因为只有在那里才会有结果。如果结果在第二次尝试时获得，则需要这样做。
2. 在获取结果后，需要取消注册BroadCastReceiver。
3. size = size -1 看起来是不必要的。

以下是修改过的@Android代码作为工作示例:

WifiScanner.java是主要活动

package com.arjunandroid.wifiscanner;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

public class WifiScanner extends Activity implements View.OnClickListener{


    WifiManager wifi;
    ListView lv;
    Button buttonScan;
    int size = 0;
    List<ScanResult> results;

    String ITEM_KEY = "key";
    ArrayList<String> arraylist = new ArrayList<>();
    ArrayAdapter adapter;

    /* Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        getActionBar().setTitle("Widhwan Setup Wizard");

        setContentView(R.layout.activity_wifi_scanner);

        buttonScan = (Button) findViewById(R.id.scan);
        buttonScan.setOnClickListener(this);
        lv = (ListView)findViewById(R.id.wifilist);


        wifi = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        if (wifi.isWifiEnabled() == false)
        {
            Toast.makeText(getApplicationContext(), "wifi is disabled..making it enabled", Toast.LENGTH_LONG).show();
            wifi.setWifiEnabled(true);
        }
        this.adapter =  new ArrayAdapter<>(this,android.R.layout.simple_list_item_1,arraylist);
        lv.setAdapter(this.adapter);

        scanWifiNetworks();
    }

    public void onClick(View view)
    {
        scanWifiNetworks();
    }

    private void scanWifiNetworks(){

        arraylist.clear();
        registerReceiver(wifi_receiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));

        wifi.startScan();

        Log.d("WifScanner", "scanWifiNetworks");

        Toast.makeText(this, "Scanning....", Toast.LENGTH_SHORT).show();

    }

    BroadcastReceiver wifi_receiver= new BroadcastReceiver()
    {

        @Override
        public void onReceive(Context c, Intent intent)
        {
            Log.d("WifScanner", "onReceive");
            results = wifi.getScanResults();
            size = results.size();
            unregisterReceiver(this);

            try
            {
                while (size >= 0)
                {
                    size--;
                    arraylist.add(results.get(size).SSID);
                    adapter.notifyDataSetChanged();
                }
            }
            catch (Exception e)
            {
                Log.w("WifScanner", "Exception: "+e);

            }


        }
    };

}

activity_wifi_scanner.xml是该Activity的布局文件。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:padding="10dp"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ListView
        android:id="@+id/wifilist"
        android:layout_width="match_parent"
        android:layout_height="312dp"
        android:layout_weight="0.97" />


    <Button
        android:id="@+id/scan"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_gravity="bottom"
        android:layout_margin="15dp"
        android:background="@android:color/holo_green_light"
        android:text="Scan Again" />
</LinearLayout>

同样如上所述，不要忘记在AndroidManifest.xml中添加Wifi权限。

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" /> 

- antman

Answer 5

请参考以下链接，获取已从列表中删除冗余 SSID 的 ScanResult：

扫描 WiFi 结果中的重复 SSID

- vikoo