ConnectivityManager主要管理和网络连接相关的操作，NetworkInfo类包含了对wifi和mobile两种网络模式连接的详细描述,通过其getState()方法获取的State对象则代表着连接成功与否等状态。

CONNECTED

Detailed state	Coarse-grained state
IDLE	DISCONNECTED
SCANNING	CONNECTING
CONNECTING	CONNECTING
AUTHENTICATING	CONNECTING
CONNECTED
DISCONNECTING	DISCONNECTING
DISCONNECTED	DISCONNECTED
UNAVAILABLE	DISCONNECTED
FAILED	DISCONNECTED

       State state = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState();  

 if(State.CONNECTED==state){  

  Log.i("TAG", "GPRS网络已连接");  

 }  

   

 state = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState();  

 if(State.CONNECTED==state){  

  Log.i("TAG“, "WIFI网络已连接");  

 } 

//判断网络是否可用 public static boolean isNetworkAvaiable(Context context){ ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(CONNECTIVITY_SERVICE); NetworkInfo info = connectivityManager.getActiveNetworkInfo(); // 获取代表联网状态的NetWorkInfo对象 return (info != null && info.isConnected()); } //判断WIFI是否可用 public static boolean isWifiActive(Context context){ ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(CONNECTIVITY_SERVICE); NetworkInfo[] info = connectivityManager.getAllNetworkInfo(); if(info!=null){ for(int i=0;i<info.length;i++){ // if(info[i].getTypeName().equals(ConnectivityManager.TYPE_WIFI)&& info[i].isConnected()) return true; } } return false; }

ConnectivityManager.TYPE_WIFI 表示wifi连接

ConnectivityManager.TYPE_MOBILE 表示3G连接

网络设置Intent:

new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS)   // 跳转到无线网络设置界面 

new Intent(android.provider.Settings.ACTION_WIFI_SETTINGS) // 跳转到无线wifi网络设置界面 

最后别忘了在mainifest文件中加上权限：

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