android - Wifi 扫描结果广播接收器不工作

Question

我编写了一个简单的广播接收器来在 wifi 扫描完成时显示 toast 消息。什么都没有显示。这是我的代码:

package com.wifi;

import java.util.List;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import android.widget.Toast;

public class wifiReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        Toast.makeText(context,"Scan completed", Toast.LENGTH_LONG).show();

    }

}

这是 list 文件:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.wifi"
      android:versionCode="1"
      android:versionName="1.0">


    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".wifi" android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    <receiver android:name=".wifiReceiver">
        <intent-filter>
            <action android:name="android.net.wifi.SCAN_RESULTS"></action>
        </intent-filter>
    </receiver>
    </application>
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
</manifest>

Answer 1

好吧，没那么容易;-)
有几样东西不见了...... 这是 wifi 扫描的示例 - 原始源代码位于此处 http://www.androidsnippets.com/scan-for-wireless-networks

package com.android.wifitester;

import java.util.List;
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.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;

public class WifiTester extends Activity {
TextView mainText;
WifiManager mainWifi;
WifiReceiver receiverWifi;
List<ScanResult> wifiList;
StringBuilder sb = new StringBuilder();

public void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.main);
   mainText = (TextView) findViewById(R.id.mainText);
   mainWifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);
   receiverWifi = new WifiReceiver();
   registerReceiver(receiverWifi, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
   mainWifi.startScan();
   mainText.setText("\\nStarting Scan...\\n");
}

public boolean onCreateOptionsMenu(Menu menu) {
    menu.add(0, 0, 0, "Refresh");
    return super.onCreateOptionsMenu(menu);
}

public boolean onMenuItemSelected(int featureId, MenuItem item) {
    mainWifi.startScan();
    mainText.setText("Starting Scan");
    return super.onMenuItemSelected(featureId, item);
}

protected void onPause() {
    unregisterReceiver(receiverWifi);
    super.onPause();
}

protected void onResume() {
    registerReceiver(receiverWifi, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
    super.onResume();
}

class WifiReceiver extends BroadcastReceiver {
    public void onReceive(Context c, Intent intent) {
        sb = new StringBuilder();
        wifiList = mainWifi.getScanResults();
        for(int i = 0; i < wifiList.size(); i++){
            sb.append(new Integer(i+1).toString() + ".");
            sb.append((wifiList.get(i)).toString());
            sb.append("\\n");
        }
        mainText.setText(sb);
    }
}
}