简单的网络状态监听

第一步、自己写一个broadcast接收者

package com.bruce.netconnectionlistener;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.widget.Toast;

/**
 * Created by Administrator on 2016/5/10 0010.
 */
public class ConnectionChangeReceiver extends BroadcastReceiver {
    private Context context;

    @Override
    public void onReceive(Context context, Intent intent) {
        this.context = context;
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo mobNetInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
        NetworkInfo wifiNetInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

        if (!mobNetInfo.isConnected() && !wifiNetInfo.isConnected()) {
            showToast("网络不可以用");
            //改变背景或者 处理网络的全局变量
        } else {
            showToast("网络可以用");
            //改变背景或者 处理网络的全局变量
        }
    }

    /**
     * 解决思路：   不用计算Toast的时间之类的，就是定义一个全局的成员变量Toast, 这个Toast不为null的时候才去make,否则直接setText
     * .为了按返回键后立即使Toast不再显示，重写父类Activity的onBackPressed()方法里面去cancel你的Toast即可.
     *
     * @param text
     */
    Toast mToast;

    public void showToast(String text) {
        if (mToast == null) {
            mToast = Toast.makeText(context, text, Toast.LENGTH_SHORT);
        } else {
            mToast.setText(text);
            mToast.setDuration(Toast.LENGTH_SHORT);
        }
        mToast.show();
    }

    public void cancelToast() {
        if (mToast != null) {
            mToast.cancel();
        }
    }
}

第二步、写一个baseactivity，作为基类，里面注册广播。

package com.bruce.netconnectionlistener;

import android.app.Activity;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.os.Bundle;

/**
 * Created by Administrator on 2016/5/10 0010.
 */
public class BaseActivity extends Activity {
    private ConnectionChangeReceiver myReceiver;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        registerReceiver();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver();
    }

    private void registerReceiver() {
        IntentFilter filter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
        myReceiver = new ConnectionChangeReceiver();
        this.registerReceiver(myReceiver, filter);
    }

    private void unregisterReceiver() {
        if (myReceiver != null) {
            this.unregisterReceiver(myReceiver);
        }
    }
}

3、在需要的类继承该baseactivity

package com.bruce.netconnectionlistener;

import android.os.Bundle;

public class MainActivity extends BaseActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

4、需要的权限

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