android-验证网络是否可用

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"/>"