SIMPLE ONE

Question

我正在使用以下代码检查我的应用中的互联网连接。

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。

每当我尝试使用F8键断开/连接网络时，我都会收到 “UNFORTUNATELY APP已停止” ，而我不是在logcat中获取任何印刷品。

我能知道我在做什么错吗？

Answer 1

您是否已在AndroidManifest.xml添加此内容？

<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

以上代码无法正常用于Wi-Fi连接。这是修改后的

SIMPLE ONE

。的AndroidManifest.xml

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

androidmanifest.xml的应用程序内部标记

<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. ");
    }
}

Answer 3

针对Android 7.0（API级别24）及更高版本的应用如果在其清单中声明广播接收器，则不会收到此广播。如果应用程序使用Context.registerReceiver（）注册其BroadcastReceiver并且该上下文仍然有效，它们仍将接收广播。

https://developer.android.google.cn/reference/android/net/ConnectivityManager.html?hl=zh-cn#CONNECTIVITY_ACTION

不幸的是，在检查网络时app正在停止

3 个答案:

SIMPLE ONE