Question

在我的Android应用程序中，我正在检查我的主要活动中是否存在这样的互联网连接。一旦互联网（数据）连接失败，它将正确显示错误。

但是当我退出应用程序并打开互联网连接并运行应用程序时，它也会显示相同的对话框（“没有互联网连接”），当我重新安装应用程序或重新启动设备时它将被清除。

我的代码

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        setContentView(R.layout.activity_main);
        setFirsLaunchFlag();

        cd = new ConnectionDetector(getApplicationContext());

        // Check if Internet present
        if (!cd.isConnectingToInternet()) {
            // Internet Connection is not present
            TextView text = (TextView) findViewById(R.id.loads);
            text.setText("Internet connection error.");
            return;
        }

... 
}

我对android很新..请帮帮我

更新

boolean connected = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        setContentView(R.layout.login_layput);

        ConnectivityManager connectivityManager =

                (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
        if(connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED || 
                connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED) {

            //we are connected to a network
            connected = true;
        }
        else
            connected = false;

        if(connected==false){
            TextView text = (TextView) findViewById(R.id.loads);
            text.setText("Internet connection error.");
            return;
        }
... 

}

Answer 1

使用此代码。

boolean connected = false;

ConnectivityManager connectivityManager =

（ConnectivityManager）getSystemService（Context.CONNECTIVITY_SERVICE）;

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

    //we are connected to a network
    connected = true;
}
else
    connected = false;

使用权限

“android.permission.ACCESS_NETWORK_STATE”

Answer 2

public static boolean hasInternet(Activity a) 
{
        try {
            boolean hasConnectedWifi = false;
            boolean hasConnectedMobile = false;
            ConnectivityManager cm = (ConnectivityManager) a.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo[] netInfo = cm.getAllNetworkInfo();
            for (NetworkInfo ni : netInfo) {
                if (ni.getTypeName().equalsIgnoreCase("wifi"))
                    if (ni.isConnected())
                        hasConnectedWifi = true;
                if (ni.getTypeName().equalsIgnoreCase("mobile"))
                    if (ni.isConnected())
                        hasConnectedMobile = true;
            }
            return hasConnectedWifi || hasConnectedMobile;
        }
        catch (Exception ex) {
        }
        return false;

}

使用此方法检查您是否有互联网连接...如果有互联网，此方法将返回布尔值true，如果没有互联网则返回false

Android无互联网连接检测不变

2 个答案: