嵌套片段中的按钮在单击时不执行任何操作

所以早些时候我创建了一个导航抽屉，其中每个项目打开一个 Fragment 活动。其中之一称为“规划”，这就是我遇到问题的地方。我想在计划活动中添加一个片段（这也是一个片段）。

目的是添加一个日期选择器片段。当点击一个按钮时，一个对话片段应该打开一个 minicalendar 视图，以请求用户提供日期。此外，该日期然后存储在文本视图中。

不幸的是，当我点击按钮时什么也没有发生。没有动作，也没有错误或崩溃，这让我很难调试。

这是我的代码：

称为计划的主机片段（没有导入）：

public class planning extends Fragment implements DatePickerDialog.OnDateSetListener{
    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    private OnFragmentInteractionListener mListener;

    public planning() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment planning.
     */
    // TODO: Rename and change types and number of parameters
    public static planning newInstance(String param1, String param2) {
        planning fragment = new planning();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }



    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }


    }



    @Override
    public void onDateSet(DatePicker view, int year, int month, int day) {
        Calendar c = Calendar.getInstance();
        c.set(Calendar.YEAR,year);
        c.set(Calendar.MONTH,month);
        c.set(Calendar.DAY_OF_MONTH,day);

        String currentDateString = DateFormat.getDateInstance().format(c.getTime());
        TextView textView = getView().findViewById(R.id.view_date);
        textView.setText(currentDateString);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_planning,
                container, false);
        Button button = (Button)view.findViewById(R.id.b_datepicker);
        button.setOnClickListener(new View.OnClickListener() {
                                      @Override
                                      public void onClick(View v) {

                                       DialogFragment datePicker = new DatePickerFragment();
                                       datePicker.show(getFragmentManager(), "date picker");
                                      }
                                      });



                //

        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_planning, container, false);



    }

    // TODO: Rename method, update argument and hook method into UI event
    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);

    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        void onFragmentInteraction(Uri uri);
    }
}

这是规划 XML（带有片段的框架布局）：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".Fragments.planning">


    <!-- TODO: Update blank fragment layout -->
    <FrameLayout
        android:id="@+id/date_picker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">




    </FrameLayout>

    <Button
        android:id="@+id/b_datepicker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="true"
        android:text="open date picker" />


    <TextView
        android:id="@+id/view_date"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:textColor="@color/blue"
        />


</LinearLayout>

这是我想在单击按钮时显示的 DatePickerFragment：

package com.example.android.meat_timealpha10.Fragments;

import android.app.DatePickerDialog;
import android.app.Dialog;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.DialogFragment;

import java.util.Calendar;

public class DatePickerFragment extends DialogFragment {
    @NonNull
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        Calendar c = Calendar.getInstance();
        int year = c.get(Calendar.YEAR);
        int month = c.get(Calendar.MONTH);
        int day = c.get(Calendar.DAY_OF_MONTH);

        return new DatePickerDialog(getActivity(), (DatePickerDialog.OnDateSetListener) getActivity(), year, month, day );
    }
}

我想问题出在我的计划片段的 OnCreateView 中。我尝试了不同的东西，比如在 onclicklistener 之内和之外添加这个

FragmentTransaction ft = getChildFragmentManager().beginTransaction();
        DatePickerFragment datepicker = new DatePickerFragment();
        ft.replace(R.id.date_picker, datepicker);
        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
        ft.addToBackStack(null);
        ft.commit();

但似乎没什么帮助。我希望你能帮我解决这个问题。请记住，我对 android 编程还很陌生。提前致谢！