小记：判断设备是否联网！

 1 package com.lixu.getInternet;
 2 
 3 import android.app.Activity;
 4 import android.content.Context;
 5 import android.net.ConnectivityManager;
 6 import android.net.NetworkInfo;
 7 import android.os.Bundle;
 8 import android.widget.Toast;
 9 
10 public class MainActivity extends Activity {
11 
12     @Override
13     protected void onCreate(Bundle savedInstanceState) {
14         super.onCreate(savedInstanceState);
15         setContentView(R.layout.activity_main);
16 
17         boolean b = isConnect(this);
18 
19         if (b == true)
20             Toast.makeText(this, "您的手机已经联网!", Toast.LENGTH_LONG).show();
21 
22         else if (b == false)
23             Toast.makeText(this, "您的手机没有联网！", Toast.LENGTH_LONG).show();
24 
25     }
26 
27     public boolean isConnect(Context context) {
28         ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
29         if (cm != null) {
30             NetworkInfo info = cm.getActiveNetworkInfo();
31             if (info != null && info.isConnected()) {
32                 if (info.getState() == NetworkInfo.State.CONNECTED) {
33                     return true;
34                 }
35             }
36         }
37         return false;
38     }
39 
40 }