初记：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     @Override13     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 }