从datepicker返回后如何设置编辑textview

Question

我在我的android项目中使用第三方datepicker库。此库的链接是

单击片段中的按钮时，我打开了这个日期选择器。我已经放置了这个datepicker库的所有依赖项，但是当我尝试在接口的onDateSet方法中访问edittextview时，它会显示空指针异常并且不允许我访问此edittextview

以下是我的片段的代码，当按下按钮时我打开datepicker

package com.example.anonymous.ghar_ka_khana;

import android.content.Context;
import java.util.Calendar;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.app.Fragment;
import android.support.annotation.RequiresApi;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ImageButton;   
import com.wdullaer.materialdatetimepicker.date.DatePickerDialog;
import com.wdullaer.materialdatetimepicker.time.TimePickerDialog;

public class Selling_item_detail extends Fragment implements DatePickerDialog.OnDateSetListener,TimePickerDialog.OnTimeSetListener {

    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";  
    EditText timetext;
    EditText datetext;
    int hours;
    View v;               
    private String mParam1;
    private String mParam2;   
    private OnFragmentInteractionListener mListener;    
    public Selling_item_detail() {
        // Required empty public constructor
    }

    public static Selling_item_detail newInstance(String param1, String param2) {
        Selling_item_detail fragment = new Selling_item_detail();
        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);
        }
    }

    @RequiresApi(api = Build.VERSION_CODES.N)
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {            
        v =inflater.inflate(R.layout.fragment_selling_item_detail, container, false);
        /*timetext = (EditText)v.findViewById(R.id.time);
        datetext = (EditText)v.findViewById(R.id.date);*/           
        ImageButton calendarbutton =(ImageButton)v.findViewById(R.id.dateButton);
        calendarbutton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Calendar now = Calendar.getInstance();
                DatePickerDialog dpd = DatePickerDialog.newInstance(
                        new Selling_item_detail(),
                        now.get(Calendar.YEAR),
                        now.get(Calendar.MONTH),
                        now.get(Calendar.DAY_OF_MONTH)
                );
                dpd.show(getFragmentManager(), "Datepickerdialog");
            }
        });  
        ImageButton timebutton =(ImageButton)v.findViewById(R.id.timeButton);
        timebutton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view)
            {
                Calendar now = Calendar.getInstance();
                TimePickerDialog dpd = TimePickerDialog.newInstance(
                        new Selling_item_detail(),
                        now.get(Calendar.HOUR_OF_DAY),
                        now.get(Calendar.MINUTE),
                        now.isLenient()
                );
                dpd.show(getFragmentManager(), "Datepickerdialog");
            }
        });

        return  v;
    }

    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString()+ " must implement OnFragmentInteractionListener");
        }
    }

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

    @Override
    public void onDateSet(DatePickerDialog view, int year, int monthOfYear, int dayOfMonth)
    {          
        hours=year;
        timetext = (EditText)v.findViewById(R.id.time);
        datetext = (EditText)v.findViewById(R.id.date);
        Log.i("timecontext",timetext+"");
        Log.i("datecontext",datetext+"");
        Log.i("tareekh",dayOfMonth+"-"+monthOfYear+"-"+year);
    }

    @Override
    public void onTimeSet(TimePickerDialog view, int hourOfDay, int minute, int second)
    {
      //  timetext.setText(hourOfDay+":"+second+":"+minute);
        Log.i("waqt",hourOfDay+":"+second+":"+minute);
    }

    /**
     * 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);
    }
}

此片段的XML文件如下

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginTop="?attr/actionBarSize"
    xmlns:fab="http://schemas.android.com/apk/res-auto">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:padding="24dp">

        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="220dp"
            >

            <com.mikepenz.materialdrawer.view.BezelImageView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:src="@drawable/header"
                android:id="@+id/seelingfoodimage"/>

            <com.scalified.fab.ActionButton
                android:id="@+id/cambutton"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom|start"
                fab:button_color="#ffffff"
                fab:button_colorPressed="#FF0000"
                fab:image="@drawable/cam"
                fab:image_size="34dp" />

        </FrameLayout>

        <com.github.florent37.materialtextfield.MaterialTextField
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            app:mtf_openKeyboardOnFocus="true"
            app:mtf_labelColor="#666"
            app:mtf_image="@drawable/food"
            >

            <EditText
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/foodname"
                android:hint="Foodname"
                android:layout_marginTop="10dp"
                android:textColor="#333"
                android:textSize="15sp" />

        </com.github.florent37.materialtextfield.MaterialTextField>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:orientation="horizontal">

            <com.github.florent37.materialtextfield.MaterialTextField
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                app:mtf_labelColor="#666"
                app:mtf_image="@drawable/calendar"
                app:mtf_openKeyboardOnFocus="true"
                >

                <EditText
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:id="@+id/date"
                    android:hint="Selling Location"
                    android:textColor="#333"
                    android:textSize="15sp" />

            </com.github.florent37.materialtextfield.MaterialTextField>

            <ImageButton
                android:id="@+id/dateButton"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="40dp"
                android:layout_marginLeft="5dp"
                android:src="@drawable/calendar"/>

        </LinearLayout>

        <!--com.github.florent37.materialtextfield.MaterialTextField
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:mtf_labelColor="#666"
            app:mtf_image="@drawable/calendar"
            android:layout_marginTop="10dp"
            app:mtf_openKeyboardOnFocus="true"
            >

            <EditText
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/date"
                android:layout_marginTop="10dp"
                android:hint="Date"
                android:textColor="#333"
                android:textSize="15sp" />

        </com.github.florent37.materialtextfield.MaterialTextField-->


        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:orientation="horizontal">

            <com.github.florent37.materialtextfield.MaterialTextField
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                app:mtf_labelColor="#666"
                app:mtf_image="@drawable/time"
                app:mtf_openKeyboardOnFocus="true"
                >

                <EditText
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:id="@+id/time"
                    android:hint="Selling Location"
                    android:textColor="#333"
                    android:textSize="15sp" />

            </com.github.florent37.materialtextfield.MaterialTextField>

            <ImageButton
                android:id="@+id/timeButton"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="40dp"
                android:layout_marginLeft="5dp"
                android:src="@drawable/time"/>

        </LinearLayout>

        <!--com.github.florent37.materialtextfield.MaterialTextField
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:mtf_labelColor="#666"
            android:layout_marginTop="10dp"
            app:mtf_image="@drawable/time"
            app:mtf_openKeyboardOnFocus="true"
            >

            <EditText
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/mail"
                android:hint="Time"
                android:layout_marginTop="10dp"
                android:textColor="#333"
                android:textSize="15sp" />

        </com.github.florent37.materialtextfield.MaterialTextField-->

        <com.github.florent37.materialtextfield.MaterialTextField
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:mtf_labelColor="#666"
            android:layout_marginTop="10dp"
            app:mtf_image="@drawable/plate"
            app:mtf_openKeyboardOnFocus="true"
            >

            <EditText
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/plate"
                android:hint="Number Of Plates"
                android:layout_marginTop="10dp"
                android:textColor="#333"
                android:textSize="15sp" />

        </com.github.florent37.materialtextfield.MaterialTextField>



        <com.github.florent37.materialtextfield.MaterialTextField
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:mtf_labelColor="#666"
            android:layout_marginTop="10dp"
            app:mtf_image="@drawable/money"
            app:mtf_openKeyboardOnFocus="true"
            >

            <EditText
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/money"
                android:hint="Price Per Plate"
                android:layout_marginTop="10dp"
                android:textColor="#333"
                android:textSize="15sp" />

        </com.github.florent37.materialtextfield.MaterialTextField>



    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:orientation="horizontal">

        <com.github.florent37.materialtextfield.MaterialTextField
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            app:mtf_labelColor="#666"
            app:mtf_image="@drawable/location"
            app:mtf_openKeyboardOnFocus="true"
            >

            <EditText
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/location"
                android:hint="Selling Location"
                android:textColor="#333"
                android:textSize="15sp" />

        </com.github.florent37.materialtextfield.MaterialTextField>

        <ImageButton
            android:id="@+id/mapButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="40dp"
            android:layout_marginLeft="5dp"
            android:src="@drawable/map"/>

    </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            android:layout_marginTop="20dp">

            <Button
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="wrap_content"
                android:text="OK"
                android:textColor="#ffffff"
                android:id="@+id/ok"
                android:background="@drawable/rounded_button_selector" />
            <LinearLayout
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="wrap_content">

            </LinearLayout>

            <Button
                android:layout_width="0dp"
                android:layout_weight="1"
                android:layout_height="wrap_content"
                android:text="Cancel"
                android:textColor="#ffffff"
                android:id="@+id/cancel"
                android:background="@drawable/rounded_button_selector" />

        </LinearLayout>

    </LinearLayout>
</ScrollView>
<!--ScrollView 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:background="#a1000000"
    xmlns:fab="http://schemas.android.com/apk/res-auto"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context="com.example.anonymous.ghar_ka_khana.Selling_item_detail">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <FrameLayout
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_gravity="center"
        android:id="@+id/frame"
         >
        <com.mikepenz.materialdrawer.view.BezelImageView
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:src="@drawable/header"
         android:id="@+id/seelingfoodimage"/>

        <com.scalified.fab.ActionButton
            android:id="@+id/cambutton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            fab:button_color="#ffffff"
            fab:button_colorPressed="#FF0000"
            fab:image="@drawable/cam"
            fab:image_size="34dp" />
    </FrameLayout>

    <com.github.florent37.materialtextfield.MaterialTextField
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="10dp"
        android:layout_below="@+id/frame"
        app:mtf_openKeyboardOnFocus="true"
        app:mtf_labelColor="#666"
        app:mtf_image="@drawable/ic_person_black_24dp"
        app:mtf_hasFocus="true"
        >

        <EditText
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/foodname"
            android:hint="Foodname"
            android:text="food"
            android:layout_marginTop="20dp"
            android:textColor="#333"
            android:textSize="15dp" />

    </com.github.florent37.materialtextfield.MaterialTextField-->

    <!--com.github.florent37.materialtextfield.MaterialTextField
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="10dp"
        android:layout_below="@+id/foodnames"
        android:id="@+id/dates"
        app:mtf_openKeyboardOnFocus="true"
        app:mtf_labelColor="#666"
        app:mtf_image="@drawable/calendar"
        app:mtf_hasFocus="true"
        >

        <EditText
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/date"
            android:hint="Foodname"
            android:text="food"
            android:layout_marginTop="20dp"
            android:textColor="#333"
            android:textSize="15sp" />

    </com.github.florent37.materialtextfield.MaterialTextField>

    <com.github.florent37.materialtextfield.MaterialTextField
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="10dp"
        android:layout_below="@+id/dates"
        android:id="@+id/times"
        app:mtf_openKeyboardOnFocus="true"
        app:mtf_labelColor="#666"
        app:mtf_image="@drawable/time"
        app:mtf_hasFocus="true"
        >

        <EditText
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/time"
            android:hint="Foodname"
            android:text="food"
            android:layout_marginTop="20dp"
            android:textColor="#333"
            android:textSize="15sp" />

    </com.github.florent37.materialtextfield.MaterialTextField>

    <com.github.florent37.materialtextfield.MaterialTextField
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="10dp"
        android:layout_below="@+id/times"
        android:id="@+id/plates"
        app:mtf_openKeyboardOnFocus="true"
        app:mtf_labelColor="#666"
        app:mtf_image="@drawable/plate"
        app:mtf_hasFocus="true"
        >

        <EditText
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/plate"
            android:hint="Foodname"
            android:text="food"
            android:layout_marginTop="20dp"
            android:textColor="#333"
            android:textSize="15sp" />

    </com.github.florent37.materialtextfield.MaterialTextField>
    </RelativeLayout>

</ScrollView-->

Answer 1

我将自定义代码设置为打开date picker并在文本上设置日期：

public static void showDatePicker(Context context, final AppCompatEditText editText) {
    // Get Current Date
    final Calendar c = Calendar.getInstance();
    mYear = c.get(Calendar.YEAR);
    mMonth = c.get(Calendar.MONTH);
    mDay = c.get(Calendar.DAY_OF_MONTH);


    DatePickerDialog datePickerDialog = new DatePickerDialog(context,
            new DatePickerDialog.OnDateSetListener() {

                @Override
                public void onDateSet(DatePicker view, int year,
                                      int monthOfYear, int dayOfMonth) {
                    mYear = year;
                    mMonth = monthOfYear;
                    mDay = dayOfMonth;
                    editText.setText(dayOfMonth + "-" + (monthOfYear + 1) + "-" + year);

                }
            }, mYear, mMonth, mDay);
    datePickerDialog.show();
}

Answer 2

在片段的OnCreateView()中声明您的eddittext。像这样：

@RequiresApi(api = Build.VERSION_CODES.N)
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    v =inflater.inflate(R.layout.fragment_selling_item_detail, container, false);
    timetext = (EditText)v.findViewById(R.id.time);
    datetext = (EditText)v.findViewById(R.id.date);
    return v;
}

获取一个可以保存日期和时间的全局字符串。

SimpleDateFormat simpleDateFormat = new SimpleDateFormat("h:mma");
String date = mMonth+1 + "/" + mDay + "/" + mYear + " : " + simpleDateFormat.format(time);

然后在那些覆盖的方法中将日期/时间设置为eddittext。

 timetext.setText(date);