Question

我正在尝试向我的应用添加一些连接状态感知功能。使用这里的示例和google的文档，我们想出了一个接收器，它可以在连接状态发生变化时正确显示警报，但每当创建活动时也会不需要地显示警报。

ConnectStatusReceiver：

package com.zivtaller.placefinder.receivers;

 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.util.Log;
 import android.widget.Toast;

  public class ConnectStatusReceiver extends BroadcastReceiver {

private String TAG = "netReceiver";

public ConnectStatusReceiver() {
    super();
}

@Override
public void onReceive(Context context, Intent arg1) {
    ConnectivityManager cm = (ConnectivityManager) context
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
    boolean isConnected = activeNetwork != null
            && activeNetwork.isConnectedOrConnecting();
    if (isConnected) {
        Log.d(TAG, "Data connected");
        Toast.makeText(context, "Data connected", Toast.LENGTH_SHORT)
                .show();
    } else {
        Log.d(TAG, "Data not connected");
        Toast.makeText(context, "Data not connected", Toast.LENGTH_SHORT)
                .show();
    }

}

}

在活动的onResume（）中初始化和注册：

        netReceiver = new ConnectStatusReceiver();
    IntentFilter netFilter = new IntentFilter();
    netFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
    registerReceiver(netReceiver, netFilter);

Answer 1

系统可能会生成粘性广播android.net.conn.CONNECTIVITY_CHANGE意图。粘性广播在发送后留在身边。每当您注册BroadcastReceiver以侦听粘性广播时，最近广播的意图将在调用registerReceiver()时立即传递给接收方。

测试android.net.conn.CONNECTIVITY_CHANGE广播是否为粘性的简便方法是检查registerReceiver()

中onResume()来电的返回值

netReceiver = new ConnectStatusReceiver();
IntentFilter netFilter = new IntentFilter();
netFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
Intent intent = registerReceiver(netReceiver, netFilter);
if (intent != null) {
    // broadcast is sticky
}

如果您能够确定广播确实是粘性的，那么您所遇到的是预期的行为。

请参阅what is the difference between sendStickyBroadcast and sendBroadcast in Android。

Answer 2

请做，

unregisterReceiver(netReceiver);

使用onPause()方法。

Answer 3

正如Bryan Dunlap所说，你正在处理粘性意图。要检查您收到的意图是否具有粘性，请致电onReceive()

中的isInitialStickyBroadcast()

https://stackoverflow.com/a/11825203/1735100

连接变化接收器在android中得到错误的意图

3 个答案: