java.lang.InstantiationException：类没有无参数的构造 [英] java.lang.InstantiationException: class has no zero argument constructor

问题描述

我想使用一个BroadcastReceiver作为一个内部类来跟踪网络状态，但我得到了标题中的例外。我应该怎么做才能解决这个问题？

 公共类NetworkChangeReceiver扩展广播接收器{
    公共NetworkChangeReceiver（）{
    }    @覆盖
    公共无效的onReceive（上下文的背景下，意图意图）{
        最后ConnectivityManager connMgr =（ConnectivityManager）上下文
                .getSystemService（Context.CONNECTIVITY_SERVICE）;        最后android.net.NetworkInfo无线= connMgr.getNetworkInfo（ConnectivityManager.TYPE_WIFI）;        最后android.net.NetworkInfo移动= connMgr.getNetworkInfo（ConnectivityManager.TYPE_MOBILE）;        如果（wifi.isAvailable（）|| mobile.isAvailable（））{
            setupData（）;
            Log.d（Netowk可用，旗1号）;
        }    }
}
 

解决方案

您

  

内广播接收机必须是静态的（通过清单登记）

或

  

非静态广播接收机必须注册和未注册的父类中。

这一点。

我用内广播reciver，未经类中注册它。要么让静态的，舱单注册，或使其不静，注册和注销的父类中。

I am trying to use a BroadcastReceiver as an inner class to track the network state but I got the exception in the title. What should I do to fix this problem?

public class NetworkChangeReceiver extends BroadcastReceiver {
    public NetworkChangeReceiver() {
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        final ConnectivityManager connMgr = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);

        final android.net.NetworkInfo wifi = connMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

        final android.net.NetworkInfo mobile = connMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

        if (wifi.isAvailable() || mobile.isAvailable()) {
            setupData();
            Log.d("Netowk Available ", "Flag No 1");
        }

    }
}

解决方案

Your

inner Broadcast receiver must be static ( to be registered through Manifest)

OR

Non-static broadcast receiver must be registered and unregistered inside the Parent class

for this.

I was using an Inner broadcast reciver, without registering it within the class. Either make it static and register in Manifest , or Make it non static and register and unregister inside the parent class .

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