Android Wifi开关,信号,状态改变监听

在做的项目中需要显示一个WIFI状态的图标,与系统通知栏里的类似,要求动态显示WIFI信号,状态. Wifi在信号改变,开关以及状态改变时都会发送广播,我们接收这几个广播即可. 需要权限:

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

Wifi图标这里,我用了一个ImageView,使用level-list来在信号改变时切换显示的图片:

<?xml version="1.0" encoding="utf-8"?>
<level-list xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:maxLevel="0"
        android:drawable="@drawable/stateitems_wifi_0"
        android:minLevel="0"/>
    <item
        android:drawable="@drawable/stateitems_wifi_1"
        android:maxLevel="1"
        android:minLevel="1"/>
    <item
        android:drawable="@drawable/stateitems_wifi_2"
        android:maxLevel="2"
        android:minLevel="2"/>
    <item
        android:drawable="@drawable/stateitems_wifi_3"
        android:maxLevel="3"
        android:minLevel="3"/>
    <item
        android:drawable="@drawable/stateitems_wifi_4"
        android:maxLevel="4"
        android:minLevel="4"/>

</level-list>

但好像有个问题,在返回信号3时,显示的是4,满格信号,2的时候,显示的3格信号不知道问题出在哪,我确定图片没有弄错. 广播接收器:

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.NetworkInfo;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.widget.ImageView;

public class WifiStateReceiver extends BroadcastReceiver {

    ImageView wifiStateImage;
    Context context;
    public WifiStateReceiver(Context context, ImageView imageView) {
        // TODO Auto-generated constructor stub
        this.wifiStateImage=imageView;
        this.context=context;
        int strength=getStrength(context);
        wifiStateImage.setImageLevel(strength);
        
    }
    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO Auto-generated method stub
        System.out.println(intent.getAction());
        if(intent.getAction().equals(WifiManager.RSSI_CHANGED_ACTION))
        {
            int strength=getStrength(context);
            System.out.println("当前信号 "+strength);
            wifiStateImage.setImageLevel(strength);
        }else if(intent.getAction().equals(WifiManager.NETWORK_STATE_CHANGED_ACTION)){
            System.out.println("网络状态改变");
            NetworkInfo info=intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
            if(info.getState().equals(NetworkInfo.State.DISCONNECTED))
            {//如果断开连接
                wifiStateImage.setImageLevel(0);
            }
        }else if(intent.getAction().equals(WifiManager.WIFI_STATE_CHANGED_ACTION))
        {
            //WIFI开关
            int wifistate=intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE,WifiManager.WIFI_STATE_DISABLED);
            if(wifistate==WifiManager.WIFI_STATE_DISABLED)
            {//如果关闭
                wifiStateImage.setImageLevel(0);
            }
        }

    }
    public int getStrength(Context context)
    {
        WifiManager wifiManager = (WifiManager) context
                .getSystemService(Context.WIFI_SERVICE);
        WifiInfo info = wifiManager.getConnectionInfo();
        if (info.getBSSID() != null) {
            int strength = WifiManager.calculateSignalLevel(info.getRssi(), 5);
            // 链接速度
//			int speed = info.getLinkSpeed();
//			// 链接速度单位
//			String units = WifiInfo.LINK_SPEED_UNITS;
//			// Wifi源名称
//			String ssid = info.getSSID();
            return strength;
            
        }
        return 0;
    }

}

注册广播接收器:

        //WIFI状态接收器
        WifiStateReceiver wifiReceiver=new WifiStateReceiver(this,wifi_state);
        IntentFilter filter=new IntentFilter();
        filter.addAction(WifiManager.RSSI_CHANGED_ACTION);
        filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
        filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
        this.registerReceiver(wifiReceiver,filter);

要加上三个Action