NetworkInfo 无法正确响应运行 Nougat 的手机上的网络更改

前言：这在运行 6.0.1 的手机上运行得很好。但在我运行 7.1.1 的手机上，却不是这样，如下所示。

build.gradle（模块：应用程序）

compileSdkVersion 25
buildToolsVersion "25.0.0"
applicationId "com.gesslar.threshvote"
minSdkVersion 19
targetSdkVersion 25

AndroidManifest.xml

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

    <receiver
        android:name=".NetworkChangeReceiver"
        android:enabled="true"
        android:exported="true">
        <intent-filter>
            <action android:name="android.net.wifi.WIFI_STATE_CHANGED"/>
            <action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
        </intent-filter>
    </receiver>

NetworkUtil.java我有一个 BroadcastReceiver，用来简单地调用 NetworkUtil.updateNetworkStatus(context);

public static void updateNetworkStatus(Context context) {
    final ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    final NetworkInfo activeNetwork = connectivityManager.getActiveNetworkInfo();
    if (activeNetwork == null) {
        Log.d(TAG, "NO CONNECTION INFORMATION");
        return;
    }
    if (activeNetwork.isConnected()) {
        Log.d(TAG, "WE ARE CONNECTED TO A NETWORK");
    } else {
        Log.d(TAG, "WE ARE NOT CONNECTED TO A NETWORK");
        return;
    }
    Log.d(TAG, "NETWORK TYPE: " + activeNetwork.getTypeName());
}

从 WiFi 和数据连接开始我做了以下测试 关闭 WiFi

03-08 20:15:04.664 29796-29796/com.gesslar.threshvote D/NetworkUtil: NO CONNECTION INFORMATION

打开 WiFi：

03-08 20:15:26.333 29796-29796/com.gesslar.threshvote D/NetworkUtil: WE ARE CONNECTED TO A NETWORK
03-08 20:15:26.333 29796-29796/com.gesslar.threshvote D/NetworkUtil: NETWORK TYPE: MOBILE

关闭数据：

No log line written

打开数据：

No log line written

关闭 WiFi，然后关闭数据：

1) 03-08 20:17:13.029 29796-29796/com.gesslar.threshvote D/NetworkUtil: NO CONNECTION INFORMATION
2) No log line written

两者均关闭后，打开 WiFi：

03-08 20:18:00.198 29796-29796/com.gesslar.threshvote D/NetworkUtil: NO CONNECTION INFORMATION
^ showed as soon as it started seeking for WiFi, but no further log line was written when WiFi became active.

我对结果感到非常困惑。我在其他地方看到我应该在运行时绑定它，但是，我唯一的活动是首选项活动。该应用程序并不打算具有运行时 UI，而是使用后台 IntentService 和通知。

根据安卓文档 https://developer.android.com/training/monitoring-device-state/connectivity-monitoring.html,

面向 Android 7.0（API 级别 24）及更高版本的应用不会收到 CONNECTIVITY_ACTION 如果声明了广播接收器则进行广播 在他们的清单中。应用仍会收到 CONNECTIVITY_ACTION 如果他们注册了 BroadcastReceiver 则广播 Context.registerReceiver() 并且该上下文仍然有效。

所以你需要做的是开始一个Service，创建广播接收器的新实例NetworkChangeReceiver并注册以收听android.net.conn.CONNECTIVITY_CHANGE通过使用

registerReceiver(new NetworkChangeReceiver(), new IntentFilter("android.net.conn.CONNECTIVITY_CHANGE"))