Android设备判断网络连接状态，android网络连接,所需权限（Android

Android设备判断网络连接状态，android网络连接,所需权限（Android

所需权限（AndroidManifest.xml文件中添加）：

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

Java代码（MainActivity.java文件）```java package com.example.androidtest;

import android.net.ConnectivityManager;  import android.net.NetworkInfo;  import android.net.NetworkInfo.State;  import android.os.Bundle;  import android.app.Activity;  import android.content.Context;  import android.util.Log;  import android.view.Menu;public class MainActivity extends Activity {    @Override      protected void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          setContentView(R.layout.activity_main);        boolean bFlag = isNetworkAvailable(this.getApplicationContext());          if (bFlag) {              Log.i("Network state - ", "connected");          } else {              Log.i("Network state - ", "disconnected");          }    }    /**      * 判断网络连接状况      *       * @param ctx      * @return      */      public boolean isNetworkAvailable(Context ctx) {          boolean bFlag = false;          if (ctx != null) {              ConnectivityManager conMan = (ConnectivityManager) ctx                      .getSystemService(Context.CONNECTIVITY_SERVICE);              if (conMan != null) {                  // wifi Network                  NetworkInfo nInfoW = conMan                          .getNetworkInfo(ConnectivityManager.TYPE_WIFI);                  if (nInfoW != null) {                      State wifi = nInfoW.getState();                      if (State.CONNECTED == wifi) {                          bFlag = true;                      }                  }                  if (!bFlag) {                      // mobile Network                      NetworkInfo nInfoM = conMan                              .getNetworkInfo(ConnectivityManager.TYPE_MOBILE);                      if (nInfoM != null) {                          State mobile = nInfoM.getState();                          if (State.CONNECTED == mobile) {                              bFlag = true;                          }                      }                  }              }          }          return bFlag;      }    @Override      public boolean onCreateOptionsMenu(Menu menu) {          // Inflate the menu; this adds items to the action bar if it is present.          getMenuInflater().inflate(R.menu.activity_main, menu);          return true;      }}

```isNetworkAvailable方法里先做wifi连接状态判断，如果wifi未连接，再做2g/3g/4g...手机网连接状态判断。