13

我正在做一个通过应用程序使用 Internet 连接的应用程序。如果在使用应用程序时互联网连接丢失，应用程序将被强制关闭。为避免这种情况，如果互联网不可用，我想显示一条警报消息。我怎样才能做到这一点。在登录时，我正在使用以下代码检查连接。但是我怎样才能在后台为整个应用程序做到这一点。

private boolean haveInternet(){
        NetworkInfo info = ((ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();
        if (info==null || !info.isConnected()) {
                return false;
        }
        if (info.isRoaming()) {
                // here is the roaming option you can change it if you want to disable internet while roaming, just return false
                return true;
        }
        return true;
}

谢谢..

4

1 回答 1

42

您应该BroadcastReceiver在连接状态发生变化时触发一个：

     public class BroadCastSampleActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        this.registerReceiver(this.mConnReceiver,
                new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
    }
    private BroadcastReceiver mConnReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            boolean noConnectivity = intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);
            String reason = intent.getStringExtra(ConnectivityManager.EXTRA_REASON);
            boolean isFailover = intent.getBooleanExtra(ConnectivityManager.EXTRA_IS_FAILOVER, false);

            NetworkInfo currentNetworkInfo = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);
            NetworkInfo otherNetworkInfo = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager.EXTRA_OTHER_NETWORK_INFO);

            if(currentNetworkInfo.isConnected()){
                Toast.makeText(getApplicationContext(), "Connected", Toast.LENGTH_LONG).show();
            }else{
                Toast.makeText(getApplicationContext(), "Not Connected", Toast.LENGTH_LONG).show();
            }
        }
    };
}

然后在你的AndroidManifest你可以检查你是否有连接：

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

下载源代码 -这里

于 2012-04-27T12:22:03.810 回答