不幸的是,在检查网络时app正在停止

Question

我使用以下代码通过我的应用程序检查互联网连接.

public class ConnectionChangeReceiver extends BroadcastReceiver
{
  @Override
  public void onReceive( Context context, Intent intent )
  {
    ConnectivityManager connectivityManager = (ConnectivityManager)context.getSystemService( Context.CONNECTIVITY_SERVICE );
    NetworkInfo activeNetInfo = connectivityManager.getActiveNetworkInfo();
    NetworkInfo mobNetInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE );

    if (activeNetInfo != null)
    {
        Toast.makeText( context, "Active Network Type : " + 
                       activeNetInfo.getTypeName(), Toast.LENGTH_SHORT ).show();
    }
    if(mobNetInfo != null)
    {
        Toast.makeText( context, "Mobile Network Type : " + 
                          mobNetInfo.getTypeName(), Toast.LENGTH_SHORT ).show();
    }
  }
}

我已在清单文件中定义了必需的权限.

每当我试图断开/连接使用F8键,我会收到网络"不幸的是APP已经停止",而我没有得到任何打印logcat.

我能知道我在做什么错吗？

Answer 1

你加入了AndroidManifest.xml吗？

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

如果您已添加以上内容,请检查此代码:

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

和

public class UpdateReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {

          ConnectivityManager connectivityManager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE );
          NetworkInfo activeNetInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
          boolean isConnected = activeNetInfo != null && activeNetInfo.isConnectedOrConnecting();   
          if (isConnected)       
              Log.i("NET", "Connected" + isConnected);   
          else 
              Log.i("NET", "Not Connected" + isConnected);
    }
}

注意:如果您的目标是Android N Preview.上面的接收器不会受到Google限制的限制.

链接:https://developer.android.com/preview/features/background-optimization.html#connectivity-action

Answer 2

上面的代码不能正常用于Wi-Fi连接.这是修改

简单一个

.AndroidManifest.xml中

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

androidmanifest.xml的内部应用程序标签

<receiver android:name="android.YOUR-JAVA-CLASS-PATH.BackgroundSync" android:enabled="true">
      <intent-filter>
          <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
      </intent-filter>
</receiver>

BackgroundSync.java

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

public class BackgroundSync extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) { 
        ConnectivityManager cm =(ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        if (cm.getActiveNetworkInfo()!=null){
            Toast.makeText(context, "Connected to Internet", Toast.LENGTH_LONG).show();
        }
        else Log.i("INTERNET","---------------------> Internet Disconnected. ");
    }
}