Android利用廣播監聽設備網絡連接(斷網)的變化情況

package cc.testnetworkchange;
import android.os.Bundle;
import android.app.Activity;
/**
 * Demo描述:
 * 利用廣播監聽設備網絡連接的變化情況
 * 亦可借此監測到設備是否已經斷開網絡
 */
public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
	}
}

package cc.testnetworkchange;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.NetworkInfo.State;

public class NetWorkChangeBroadcastReceiver extends BroadcastReceiver {

	@Override
	public void onReceive(Context context, Intent intent) {
		ConnectivityManager connectivityManager=
		(ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
		if (connectivityManager!=null) {
			NetworkInfo [] networkInfos=connectivityManager.getAllNetworkInfo();
			for (int i = 0; i < networkInfos.length; i++) {
				State state=networkInfos[i].getState();
				if (NetworkInfo.State.CONNECTED==state) {
					System.out.println("------------> Network is ok");
					return;
				}
			}
		}
		
		//沒有執行return,則說明當前無網絡連接
		System.out.println("------------> Network is validate");
		intent.setClass(context, NetWorkErrorActivity.class);
		intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intent);
	}

}

package cc.testnetworkchange;
import android.os.Bundle;
import android.app.Activity;
public class NetWorkErrorActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.networkerror);
	}
}