Android-驗證網絡是否可用

ConnectivityManager主要管理和網絡連接相關的操作，NetworkInfo類包含了對wifi和mobile兩種網絡模式連接的詳細描述,通過其getState()方法獲取的State對象則代表著連接成功與否等狀態。

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網絡已連接");  
 }  
   
 state = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState();  
 if(State.CONNECTED==state){  
  Log.i("TAG“, "WIFI網絡已連接");  
 } 

1. //判斷網絡是否可用   
2.   
3. public static boolean isNetworkAvaiable(Context context){  
4.     ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(CONNECTIVITY_SERVICE);  
5.     NetworkInfo info = connectivityManager.getActiveNetworkInfo(); // 獲取代表聯網狀態的NetWorkInfo對象     
6.     return (info != null && info.isConnected());  
7. }  
8.   
9. //判斷WIFI是否可用   
10.   
11. public static boolean isWifiActive(Context context){  
12.       
13.     ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(CONNECTIVITY_SERVICE);  
14.     NetworkInfo[] info = connectivityManager.getAllNetworkInfo();  
15.     if(info!=null){  
16.         for(int i=0;i<info.length;i++){  
17.             //   
18.             if(info[i].getTypeName().equals(ConnectivityManager.TYPE_WIFI)&& info[i].isConnected())  
19.                 return true;  
20.         }  
21.     }  
22.     return false;  
23. }  

ConnectivityManager.TYPE_WIFI 表示wifi連接

ConnectivityManager.TYPE_MOBILE 表示3G連接

網絡設置Intent:

new Intent(Android.provider.Settings.ACTION_WIRELESS_SETTINGS)   // 跳轉到無線網絡設置界面 

new Intent(android.provider.Settings.ACTION_WIFI_SETTINGS) // 跳轉到無線wifi網絡設置界面 

最後別忘了在mainifest文件中加上權限：

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