android开发中，在做网络请求前判断当前网络连接状态有时很有必要。本文将介绍如何获取android设备当前网络连接状态！
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）
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。