Android 網絡連接的變更

監聽網絡連接的變更

package com.fengtai.utils;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.telephony.TelephonyManager;
import java.util.ArrayList;
import java.util.List;

/**
 * 監聽網絡改變的廣播接收者
 * @author Administrator
 *
 */
public class NetChangeReceiver extends BroadcastReceiver {

    /**
     * 枚舉網絡狀態
     * NET_NO：沒有網絡
     * NET_2G:2g網絡
     * NET_3G：3g網絡
     * NET_4G：4g網絡
     * NET_WIFI：wifi
     * NET_UNKNOWN：未知網絡
     */
    public static enum NetState{NET_NO,NET_2G,NET_3G,NET_4G,NET_WIFI,NET_UNKNOWN};

    public static List<NetEventHandle> ehList = new ArrayList<NetEventHandle>();

    public static interface NetEventHandle {
        /**
         * 網絡狀態碼
         * @param netCode
         */
        void netState(NetState netCode);
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        //向所有實現接口的activity傳遞消息
        for (NetEventHandle e : ehList) {
            e.netState(isConnected(context));
        }
    }

    /**
     * 判斷當前是否網絡連接,返回網絡類型
     *
     * @param context
     * @return 狀態碼
     */
    public static NetState isConnected(Context context) {
        NetState stateCode = NetState.NET_NO;
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo ni = cm.getActiveNetworkInfo();
        if (ni != null && ni.isConnectedOrConnecting()) {
            switch (ni.getType()) {
                case ConnectivityManager.TYPE_WIFI:
                    stateCode = NetState.NET_WIFI;
                    break;
                case ConnectivityManager.TYPE_MOBILE:
                    switch (ni.getSubtype()) {
                        case TelephonyManager.NETWORK_TYPE_GPRS: //聯通2g
                        case TelephonyManager.NETWORK_TYPE_CDMA: //電信2g
                        case TelephonyManager.NETWORK_TYPE_EDGE: //移動2g
                        case TelephonyManager.NETWORK_TYPE_1xRTT:
                        case TelephonyManager. NETWORK_TYPE_IDEN:
                            stateCode = NetState.NET_2G;
                            break;
                        case TelephonyManager.NETWORK_TYPE_EVDO_A: //電信3g
                        case TelephonyManager.NETWORK_TYPE_UMTS:
                        case TelephonyManager.NETWORK_TYPE_EVDO_0:
                        case TelephonyManager.NETWORK_TYPE_HSDPA:
                        case TelephonyManager.NETWORK_TYPE_HSUPA:
                        case TelephonyManager.NETWORK_TYPE_HSPA:
                        case TelephonyManager.NETWORK_TYPE_EVDO_B:
                        case TelephonyManager.NETWORK_TYPE_EHRPD:
                        case TelephonyManager.NETWORK_TYPE_HSPAP:
                            stateCode = NetState.NET_3G;
                            break;
                        case TelephonyManager.NETWORK_TYPE_LTE:
                            stateCode = NetState.NET_4G;
                            break;
                        default:
                            stateCode = NetState.NET_UNKNOWN;
                    }
                    break;
                default:
                    stateCode = NetState.NET_UNKNOWN;
            }
        }
        return stateCode;
    }
}

在Activity的中實現NetEventHandle藉口。實現裏邊的抽象方法。

	@Override
	public void netState(NetState netCode) {
		// TODO Auto-generated method stub
		getNetState(netCode);
	}

	/**
	 * 判斷當前的網絡狀態
	 * @param netCode
	 */
	public void getNetState(NetState netCode) {
		switch (netCode) {
		case NET_NO:
			System.out.println("沒有網絡連接");
			break;
		case NET_2G:
			System.out.println("2g網絡");
			if(IMflag==1){
				LoginIM();
			}
			break;
		case NET_3G:
			System.out.println("3g網絡");
			if(IMflag==1){
				LoginIM();
			}
			break;
		case NET_4G:
			System.out.println("4g網絡");
			if(IMflag==1){
				LoginIM();
			}
			break;
		case NET_WIFI:
			System.out.println("WIFI網絡");
			if(IMflag==1){
				LoginIM();
			}
			break;
		case NET_UNKNOWN:
			System.out.println("未知網絡");
			break;
		default:
		}
	}

注意：還有在Activity的OnCreate方法中，添加NetChangeReceiver.ehList.add(this);在OnDestory（）中添加NetChangeReceiver.ehList.remove(this);