public static boolean isNetworkAvailable(Context context) {
        ConnectivityManager connectivity = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
        if (connectivity == null) {
            Log.i("NetWorkState", "Unavailabel");
            return false;
        } else {
            NetworkInfo[] info = connectivity.getAllNetworkInfo();
            if (info != null) {
                for (int i = 0; i < info.length; i++) {
                    if (info[i].getState() == NetworkInfo.State.CONNECTED) {
                        Log.i("NetWorkState", "Availabel");
                        return true;
                    }
                }
            }
        }
        return false;
    }

public static boolean isNetworkAvailable(Context context) { ConnectivityManager connectivity = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE); if (connectivity == null) { Log.i("NetWorkState", "Unavailabel"); return false; } else { NetworkInfo[] info = connectivity.getAllNetworkInfo(); if (info != null) { for (int i = 0; i < info.length; i++) { if (info[i].getState() == NetworkInfo.State.CONNECTED) { Log.i("NetWorkState", "Availabel"); return true; } } } } return false; }

 

上面这个方法就是判断网络是否连接的代码，返回true表示有网络，返回false表示无网络。  在Android网络应用程序开发中，经常要判断网络连接是否可用，因此经常有必要监听网络状态的变化。android的网络状态监听可以用BroadcastReceiver来接收网络状态改变的广  播，具体实现如下：

@Override
public void onReceive(Context context, Intent intent) {
Log.e(TAG, "网络状态改变");

boolean success = false;

//获得网络连接服务
ConnectivityManager connManager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
// State state = connManager.getActiveNetworkInfo().getState();
State state = connManager.getNetworkInfo(
ConnectivityManager.TYPE_WIFI).getState(); // 获取网络连接状态
if (State.CONNECTED == state) { // 判断是否正在使用WIFI网络
success = true;
}

state = connManager.getNetworkInfo(
ConnectivityManager.TYPE_MOBILE).getState(); // 获取网络连接状态
if (State.CONNECTED != state) { // 判断是否正在使用GPRS网络
success = true;
}

if (!success) {
Toast.makeText(LocationMapActivity.this, "您的网络连接已中断", Toast.LENGTH_LONG).show();
}

}

@Override public void onReceive(Context context, Intent intent) { Log.e(TAG, "网络状态改变"); boolean success = false; //获得网络连接服务 ConnectivityManager connManager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE); // State state = connManager.getActiveNetworkInfo().getState(); State state = connManager.getNetworkInfo( ConnectivityManager.TYPE_WIFI).getState(); // 获取网络连接状态 if (State.CONNECTED == state) { // 判断是否正在使用WIFI网络 success = true; } state = connManager.getNetworkInfo( ConnectivityManager.TYPE_MOBILE).getState(); // 获取网络连接状态 if (State.CONNECTED != state) { // 判断是否正在使用GPRS网络 success = true; } if (!success) { Toast.makeText(LocationMapActivity.this, "您的网络连接已中断", Toast.LENGTH_LONG).show(); } }

在Activity的onCreate中:

//注册网络监听
IntentFilter filter = new IntentFilter();
filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
registerReceiver(mNetworkStateReceiver, filter);
//在Activity中的onDestroy中:'

unregisterReceiver(mNetworkStateReceiver); //取消监听

//注册网络监听 IntentFilter filter = new IntentFilter(); filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION); registerReceiver(mNetworkStateReceiver, filter); //在Activity中的onDestroy中:' unregisterReceiver(mNetworkStateReceiver); //取消监听