你如何检查android中的互联网连接？

Question

我想检查每项活动的互联网连接.如果丢失,则应显示消息.

任何人都可以指导我如何实现这一目标吗？

Answer 1

任何一个点上只能有一个连接处于活动状态.所以更简单的答案是:

final ConnectivityManager conMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
final NetworkInfo activeNetwork = conMgr.getActiveNetworkInfo();
if (activeNetwork != null && activeNetwork.isConnected()) {
    // notify user you are online
} else {
    // notify user you are not online
} 

它还适用于任何新类型的网络,如ConnectivityManager#TYPE_WIMAX

还要确保您具有监视网络状态所需的权限.您需要将此权限添加到AndroidManifest.xml:

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

Answer 2

您可以使用ConnectivityManager检查网络状态.

ConnectivityManager conMgr = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);

if ( conMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED 
    || conMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED ) {

    // notify user you are online

}
else if ( conMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.DISCONNECTED 
    || conMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.DISCONNECTED) {

    // notify user you are not online
}

请注意,常量ConnectivityManager.TYPE_MOBILE和ConnectivityManager.TYPE_WIFI表示连接类型,这两个值并非详尽无遗.请参阅此处以获取详尽的清单.

还要确保您具有监视网络状态所需的权限.您需要将此权限添加到AndroidManifest.xml:

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

Answer 3

您可以针对各种类型的网络状态执行此操作

public void  checkNetworkStatus(){

    final ConnectivityManager connMgr = (ConnectivityManager)
     this.getSystemService(Context.CONNECTIVITY_SERVICE);

     final android.net.NetworkInfo wifi =
     connMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

     final android.net.NetworkInfo mobile =
     connMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

     if( wifi.isAvailable() ){

     Toast.makeText(this, "Wifi" , Toast.LENGTH_LONG).show();
     }
     else if( mobile.isAvailable() ){

     Toast.makeText(this, "Mobile 3G " , Toast.LENGTH_LONG).show();
     }
     else
     {

         Toast.makeText(this, "No Network " , Toast.LENGTH_LONG).show();
     }

}

Answer 4

您可以直接查看Mobile和Wi-Fi的网络覆盖范围和数据可用性

对于网络覆盖可用性,

private boolean isNetworkAvailable()
{
 ConnectivityManager conxMgr = (ConnectivityManager)getSystemService(CONNECTIVITY_SERVICE);

 NetworkInfo mobileNwInfo = conxMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
 NetworkInfo wifiNwInfo   = conxMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

return ((mobileNwInfo== null ? false : mobileNwInfo.isAvailable()) || (wifiNwInfo == null ? false : wifiNwInfo.isAvailable()));

}

对于数据的可用性,如果网络可用

private boolean isDataAvailable()
{
  ConnectivityManager conxMgr = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);

 NetworkInfo mobileNwInfo = conxMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
 NetworkInfo wifiNwInfo   = conxMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

return ((mobileNwInfo== null? false : mobileNwInfo.isConnected() )|| (wifiNwInfo == null? false : wifiNwInfo.isConnected()));
}

Answer 5

更正

if ( conMgr.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTED 
    ||  conMgr.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTING  ) {
   //notify user you are online
}

应该

if ( conMgr.getNetworkInfo(0).getState() == NetworkInfo.State.CONNECTED 
    ||  conMgr.getNetworkInfo(1).getState() == NetworkInfo.State.CONNECTED ) {
    //notify user you are online
}