Question

我发现了很多关于如何检查互联网访问的主题。但我无法理解如何动态制作它。例如，我发送一个请求（它将在另一个线程中工作），并且设备丢失了Internet连接。我如何取消对此活动的请求？

Answer 1

这是我之前做过的东西;也许它会有所帮助：

public class NetworkStateMonitor extends BroadcastReceiver {
    public interface Listener {
        void onNetworkStateChange(boolean up);
    }
    Context     mContext;
    boolean     mIsUp;

    public
    NetworkStateMonitor(Context context) {
        mContext = context;
        //mListener = (Listener)context;
        IntentFilter intentFilter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
        context.registerReceiver(this, intentFilter);
        mIsUp = isUp();
    }
    public void
    unregister() {  // call this when finished with it, and no later than onStop(): callback will crash if app has been destroyed
        mContext.unregisterReceiver(this);
    }
    public boolean
    isUp() {        // can be called at any time
        ConnectivityManager connectivityManager = (ConnectivityManager) mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
        return activeNetworkInfo!=null && activeNetworkInfo.isConnectedOrConnecting();
    }
    @Override public void
    onReceive(Context context, Intent intent) {     // registerReceiver callback, passed to mListener
        boolean upNow = isUp();
        if (upNow == mIsUp) return;     // no change
        mIsUp = upNow;
        ((Listener)mContext).onNetworkStateChange(mIsUp);
    }
}

Answer 2

这是我的建议，在您的函数中调用此方法以了解互联网是否可用

private boolean isNetworkConnected() {
  ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

  return cm.getActiveNetworkInfo() != null;
 }

在你的清单中

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

或者您可以将该方法放在父活动或片段中（有条件的）。

Answer 3

您可以使用连接管理器

ConnectivityManager cm =
          (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);

 NetworkInfo activeNetwork =   cm.getActiveNetworkInfo();
  boolean isConnected = activeNetwork != null &&
                     activeNetwork.isConnectedOrConnecting();

如何实时检查Internet访问？

3 个答案: