互联网连接更改广播未发生

Question

由于某种原因，我的网络更改接收器无法正常工作，并向我的 Android 应用程序中的 NetworkStateReceiver 类广播 CONNECTIVITY_CHANGE。我检查了它是否只是我的对话框的问题，但应该打印出来的 Log.d 不是。

这是 AndroidManifest.xml 的代码：

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<receiver android:name="com.main.main.NetworkStateReceiver">
        <intent-filter>
            <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
        </intent-filter>
    </receiver>

这是 NetworkStateReceiver.java 的代码：

package com.main.main;

import android.app.AlertDialog;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.util.Log;

public class NetworkStateReceiver extends BroadcastReceiver {
@Override
public void onReceive(final Context context, final Intent intent) {
    final AlertDialog dialog = new AlertDialog.Builder(context)
            .setTitle("Connection Failed")
            .setMessage("Please Check Your Internet Connection")
            .setPositiveButton("Try Again", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    //Code for try again
                }
            })
            .setNegativeButton("Exit", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {

                }
            }).create();
    if (intent.getExtras() != null) {
        final ConnectivityManager connectivityManager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
        final NetworkInfo ni = connectivityManager.getActiveNetworkInfo();
        if (ni != null && ni.isConnectedOrConnecting()) {
            Log.d("INTERNET_MESSAGE", "Connected to internet");
            dialog.dismiss();
        } else if (intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, Boolean.FALSE)) {
            Log.d("INTERNET_MESSAGE", "Disconnected from internet");
        }
    }
}

}

Answer 1

最好按如下方式检查 Internet 连接：

只需将一个通用实用程序类中的一个通用函数设为

  /*
* A Common function to check internet connection.
* */
public static boolean isOnline(Context c) {
    try {
        ConnectivityManager cm = (ConnectivityManager) c.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netInfo = cm.getActiveNetworkInfo();
        if (netInfo != null && netInfo.isConnectedOrConnecting()) {
            return true;
        }
        return false;
    } catch (Exception e) {
        e.printStackTrace();
        return false;
    }
}

现在，在您的代码中需要互联网连接的地方使用它，如下所示：

       if (isOnline(YourActivity.this)) {
            //Your Tasks..
        } else {
          //Display your AlertBox..
        }

Answer 2

您需要在清单中启用您的接收器..它会工作..

<receiver android:name="com.main.main.NetworkStateReceiver"
          android:enabled="true">
    <intent-filter>
        <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
    </intent-filter>
</receiver>