java—如何阻止在片段事务中重新创建片段

我有一个包含多个步骤的活动，每个步骤都是一个片段事务，带有一个edittext框，带有一个next/back按钮来导航并开始向用户发送输入数据。我希望能够在片段中移动，每个框中的文本保持静态。我可以毫无问题地向后移动，但是只要我单击next，下一个片段就会被重新创建，所有的东西都会丢失。
我尝试过：在oncreateview中使用虚拟视图在oncreate setretaininstance中重新提取字符串（true）；在构造函数中
使用viewpager还有其他一些关于接收数据的复杂问题，尽管这里有很多人试图提供帮助，但我无法解决这些问题，因此我别无选择，只能在我的应用程序中使用片段事务。
主/formactivity.java

package com.loopbreakr.formproject;

import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.FrameLayout;

public class FormActivity extends AppCompatActivity implements PageOne.ExitFormInteractionListener{
    //DECLARE COMPONENTS
    private FrameLayout fragmentContainer;
    private Button backToMain;
    private Button startForm;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //FIND COMPONENTS IN XML
        setContentView(R.layout.activity_form);
        fragmentContainer = findViewById(R.id.frame_layout);
        backToMain = findViewById(R.id.return_button);
        startForm = findViewById(R.id.start_button);

        //SET LISTENERS/INTENTS FOR BUTTONS
        backToMain.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

            }
        });
        startForm.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openFragments();
            }
        });
    }

    private void openFragments() {
        PageOne fragment1 = PageOne.newInstance();
        FragmentManager fragmentManager =getSupportFragmentManager();
        FragmentTransaction beginTransaction = fragmentManager.beginTransaction();
        beginTransaction.addToBackStack(null);
        beginTransaction.add(R.id.frame_layout,fragment1,"PageOne_tag");
        beginTransaction.commit();
    }

    @Override
    public void onFragmentInteraction(String answerOneText) {

    }
}

我的一个片段pageone.java

package com.loopbreakr.formproject;

import android.content.Context;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;

public class PageOne extends Fragment {

    View restored;
    private static final String SAVED = "text";
    private String savedText;
    private String answerOneString;
    private EditText answerOne;
    private ExitFormInteractionListener mListener;

    public PageOne() {
        setRetainInstance(true);
    }

    public static PageOne newInstance() {
        PageOne fragment = new PageOne();
        Bundle args = new Bundle();
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            savedText = getArguments().getString(SAVED);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        if(restored == null){
            restored = inflater.inflate(R.layout.fragment_page_one, container, false);
        }
        answerOne = restored.findViewById(R.id.answer_one);
        Button exitForm = restored.findViewById(R.id.exit_form);
        Button goNextTwo = restored.findViewById(R.id.gonext_two);

        exitForm.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                returnToDesc();
            }
        });
        goNextTwo.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                answerOneString = answerOne.getText().toString();
                sendToTwo(answerOneString);
                openSecondFragment();
            }
        });
        return restored;
    }

    private void sendToTwo(String answerOneText) {
        if(mListener != null){
            mListener.onFragmentInteraction(answerOneText);
        }
    }

    private void openSecondFragment() {
        PageTwo fragment2 = PageTwo.newInstance(answerOneString);
        FragmentTransaction fragTransition = getFragmentManager().beginTransaction();
        fragTransition.replace(R.id.frame_layout, fragment2,"PageTwo_TAG");
        fragTransition.addToBackStack(null);
        fragTransition.commit();
    }

    private void returnToDesc(){
        FragmentManager fragTransBack = getFragmentManager();
        fragTransBack.popBackStack();
    }
    public interface ExitFormInteractionListener{
        void onFragmentInteraction(String answerOneText);
    }

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

}

活动\表单.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".FormActivity">

    <androidx.constraintlayout.widget.ConstraintLayout

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

        <LinearLayout
            android:id="@+id/linearLayout"
            android:layout_width="0dp"
            android:layout_height="32dp"
            android:orientation="horizontal"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent">

        </LinearLayout>

        <TextView
            android:id="@+id/activity_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="32dp"
            android:text="@string/activity_title"
            android:textSize="32sp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            android:stateListAnimator="@null"/>

        <Button
            android:id="@+id/return_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginBottom="8dp"
            android:text="@string/return_text"
            app:layout_constraintBottom_toTopOf="@+id/linearLayout"
            app:layout_constraintStart_toStartOf="parent"
            android:stateListAnimator="@null"/>

        <Button
            android:id="@+id/start_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginBottom="8dp"
            android:text="@string/start_text"
            app:layout_constraintBottom_toTopOf="@+id/linearLayout"
            app:layout_constraintEnd_toEndOf="parent"
            android:stateListAnimator="@null"/>

        <FrameLayout
            android:id="@+id/frame_layout"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            app:layout_constraintBottom_toTopOf="@+id/linearLayout"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"/>
    </androidx.constraintlayout.widget.ConstraintLayout>
</RelativeLayout>

活动\u页面\u one.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:clickable="true"
    tools:context=".PageOne"
    android:focusable="true">
    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_height="match_parent"
        android:layout_width="match_parent">

        <TextView
            android:id="@+id/activity_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="32dp"
            android:text="@string/activity_title"
            android:textSize="32sp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            />

        <Button
            android:id="@+id/exit_form"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginBottom="8dp"
            android:text="@string/back"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            android:stateListAnimator="@null"/>

        <Button
            android:id="@+id/gonext_two"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginBottom="8dp"
            android:text="@string/next"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            android:stateListAnimator="@null"/>

        <EditText
            android:id="@+id/answer_one"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:ems="10"
            android:gravity="start|top"
            android:hint="@string/answer_one_hint"
            android:inputType="textMultiLine|textAutoCorrect"
            android:maxLines="4"
            android:minLines="4"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/activity_name"
            android:stateListAnimator="@null"/>
    </androidx.constraintlayout.widget.ConstraintLayout>

</RelativeLayout>

谢谢。

java—如何阻止在片段事务中重新创建片段

暂无答案！

相关问题

热门标签

最新问答