需要用到的許可權

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

判斷網路的工具類

package com.bwie.administrator.yuekaoalianxi.notwork;

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

public class MyNotWork {
    public static boolean getNetWork(Context context) {
        //設定一個變數
        boolean boo = false;
        //設定網路管理類  CONNECTIVITY_SERVICE  連線服務
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

        NetworkInfo info = manager.getActiveNetworkInfo();
        //isAvailable   是否可以獲得網路
        if (info != null && info.isAvailable()) {
            boo = true;
        } else {
            boo = false;
        }
        return boo;
    }
}

 

主頁面程式碼

package com.bwie.administrator.yuekaoalianxi;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;

import com.bwie.administrator.yuekaoalianxi.notwork.MyNotWork;

public class MainActivity extends AppCompatActivity {

/*    private NetWorkChangeReceiver receiver;*/

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

        boolean work = MyNotWork.getNetWork(this);
        if (work){
            Toast.makeText(this, "當前有網路連線", Toast.LENGTH_SHORT).show();
        }else{
            Toast.makeText(this, "當前無網路連線", Toast.LENGTH_SHORT).show();
        }
    }
}