Question

我正在尝试制作一个简单的应用程序，该应用程序将通知是否有可用的互联网连接，并且互联网连接发生更改。我在互联网上找到了一些解决方案，并尝试实施它们，但是不知何故，它不起作用。我已在清单文件中注册的广播接收器未调用网络连接更改。

清单

 <uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <receiver
        android:name=".NetworkStateChangeReceiver">
        <intent-filter >
            <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
        </intent-filter>
    </receiver>

</application>

广播接收器

package com.gdm.internetconnectivitycheck;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;

import static android.content.Context.CONNECTIVITY_SERVICE;

public class NetworkStateChangeReceiver extends BroadcastReceiver {

public static final String NETWORK_AVAILABLE_ACTION = "com.gdm.retailalfageek.NetworkAvailable";
public static final String IS_NETWORK_AVAILABLE = "isNetworkAvailable";

@Override
public void onReceive(Context context, Intent intent) {
    Intent networkStateIntent = new Intent(NETWORK_AVAILABLE_ACTION);
    networkStateIntent.putExtra(IS_NETWORK_AVAILABLE,  isConnectedToInternet(context));
    LocalBroadcastManager.getInstance(context).sendBroadcast(networkStateIntent);
    Log.e("Network Available ", "On receive called");
}

private boolean isConnectedToInternet(Context context) {
    try {
        if (context != null) {
            ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
            return networkInfo != null && networkInfo.isConnected();
        }
        return false;
    } catch (Exception e) {
        Log.e(NetworkStateChangeReceiver.class.getName(), e.getMessage());
        return false;
    }
}
}

主要活动

package com.gdm.internetconnectivitycheck;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.support.v4.content.LocalBroadcastManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.design.widget.Snackbar;

import static com.gdm.internetconnectivitycheck.NetworkStateChangeReceiver.IS_NETWORK_AVAILABLE;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    IntentFilter intentFilter = new IntentFilter(NetworkStateChangeReceiver.NETWORK_AVAILABLE_ACTION);
    LocalBroadcastManager.getInstance(this).registerReceiver(new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            boolean isNetworkAvailable = intent.getBooleanExtra(IS_NETWORK_AVAILABLE, false);
            String networkStatus = isNetworkAvailable ? "connected" : "disconnected";

            Snackbar.make(findViewById(R.id.main_activity), "Network Status: " + networkStatus, Snackbar.LENGTH_LONG).show();

        }
    }, intentFilter);


}
}

Answer 1

定位到Android 7.0（API级别24）及更高版本的应用必须注册以下
广播

registerReceiver(BroadcastReceiver,IntentFilter)

在清单中声明接收者无效。

CONNECTIVITY_ACTION

从Android 8.0（API级别26）开始，系统对清单声明的接收者施加了其他限制。如果您的应用定位到API级别26或更高级别，则不能使用清单，声明大多数隐式广播的接收者（不专门针对您的应用的广播）。你仍然可以当用户积极使用您的帐户时，请使用上下文注册的接收者应用程序。

直接来自官方doc。

您需要在运行时从活动注册CONNECTIVITY_CHANGE操作。使用 registerReceiver 。

IntentFilter filter = new IntentFilter();
filter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
registerReceiver(new NetworkStateChangeReceiver(), filter);

别忘了注销。

广播接收器未调用Internet连接检查

1 个答案: