Java Android BroadcastReceiver:无法实例化接收器-没有空构造函数

我的收音机有问题。如果我以这种方式在清单中声明操作：

    <receiver android:name="com.app.activity.observer.DataEntryObserver" >
        <intent-filter>
            <action android:name= "@string/action_db_updated" />
        </intent-filter>
    </receiver>

---

}需要清空构造函数

public DataEntryObserver() {
    this.dLoader = null;
}

---

您需要这样一个空构造函数：

public class DataEntryObserver extends BroadcastReceiver{

    private AppUsageLoader dLoader;

    // Empty constructor
    public DataEntryObserver() { }

    public DataEntryObserver(AppUsageLoader dLoader) {
        this.dLoader = dLoader;

        IntentFilter filter = new IntentFilter(
                ReaLifeApplication.ACTION_DB_UPDATED);
        dLoader.getContext().registerReceiver(this, filter);
    }


    @Override
    public void onReceive(Context arg0, Intent arg1) {

        // Tell the loader about the change.
        dLoader.onContentChanged();

    }
}

---

虽然我不确定保留非空构造函数是否会产生相同的错误。如果是这样，您将不得不删除它。

将该类设置为静态类，否则它将“视”为原始包含类实例的一部分

因此：

---

这不是空构造函数。将BroadcastReceiver设置为静态类是一种糟糕的体系结构。它将阻止您调用其中的许多方法，包括

startActivity

如果接收者已经在清单中，为什么要注册接收者？

   public class DataEntryObserver extends BroadcastReceiver{

private AppUsageLoader dLoader;


public DataEntryObserver(AppUsageLoader dLoader) {
    this.dLoader = dLoader;

    IntentFilter filter = new IntentFilter(
            ReaLifeApplication.ACTION_DB_UPDATED);
    dLoader.getContext().registerReceiver(this, filter);
}


@Override
public void onReceive(Context arg0, Intent arg1) {

    // Tell the loader about the change.
    dLoader.onContentChanged();

}

public DataEntryObserver() {
    this.dLoader = null;
}

public class DataEntryObserver extends BroadcastReceiver{

    private AppUsageLoader dLoader;

    // Empty constructor
    public DataEntryObserver() { }

    public DataEntryObserver(AppUsageLoader dLoader) {
        this.dLoader = dLoader;

        IntentFilter filter = new IntentFilter(
                ReaLifeApplication.ACTION_DB_UPDATED);
        dLoader.getContext().registerReceiver(this, filter);
    }


    @Override
    public void onReceive(Context arg0, Intent arg1) {

        // Tell the loader about the change.
        dLoader.onContentChanged();

    }
}

public static class DataEntryObserver extends BroadcastReceiver{
public DeviceAdminSampleReceiver() {
            super();
        }
...