java从可展开列表视图中的子级获取值

4 月 Questions & Answers 1124

我有一个可扩展的ListView（EXLV），它的每个子项都有一个EditText，EXLV外有一个按钮。已经一个星期了，我都搞砸了。 我想在单击按钮时获取在编辑文本中输入的值/数据因为我输入的值会重新生成（我不知道为什么）。任何帮助都将不胜感激。下面是一个指向整个项目的链接：https://drive.google.com/file/d/1YsCb23-wL_KBgj2braqT59mPezRhSS28/view?usp=sharing

主要活动。java：

package com.lvexpandable;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import java.util.logging.Handler;

import 安卓.Manifest;
import 安卓.app.Activity;
import 安卓.content.Context;
import 安卓.content.SharedPreferences;
import 安卓.content.pm.PackageManager;
import 安卓.os.Bundle;
import 安卓.os.CountDownTimer;
import 安卓.support.v4.app.ActivityCompat;
import 安卓.support.v7.app.AlertDialog;
import 安卓.view.View;
import 安卓.widget.Button;
import 安卓.widget.EditText;
import 安卓.widget.ExpandableListView;
import 安卓.widget.ExpandableListView.OnChildClickListener;
import 安卓.widget.ExpandableListView.OnGroupClickListener;
import 安卓.widget.ExpandableListView.OnGroupCollapseListener;
import 安卓.widget.ExpandableListView.OnGroupExpandListener;
import 安卓.widget.Toast;

public class MainActivity extends Activity {
    final int snnn=1857;

    Button btn;
    EditText edt;
    ExpandableListAdapter listAdapter;
    ExpandableListView expListView;
    List<String> listDataHeader;
    HashMap<String, List<String>> listDataChild;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        String[] mStrings = new String[20];

        // get the listview
        expListView = (ExpandableListView) findViewById(R.id.lvExp);

        // preparing list data
        prepareListData();

        listAdapter = new ExpandableListAdapter(this, listDataHeader, listDataChild);

        // setting list adapter
        expListView.setAdapter(listAdapter);


    }
    public void btnClick(View v){
        //I want to get values entered in EditTexts here. Maybe using SharedPref, in a List<> or whatever.

    }

    /*
     * Preparing the list data
     */
    private void prepareListData() {
        listDataHeader = new ArrayList<>();
        listDataChild = new HashMap<>();

        // Adding child data
        listDataHeader.add("PG");
        listDataHeader.add("Nursery");



        // Adding child data
        List<String> pg = new ArrayList<String>();
        pg.add("PG1: ");
        pg.add("PG2: ");
        pg.add("PG3: ");
        pg.add("PG4: ");
        pg.add("PG5: ");
        pg.add("PG6: ");
        pg.add("PG7: ");
        pg.add("PG8: ");
        pg.add("PG9: ");
        pg.add("PG10: ");
        pg.add("PG11: ");
        pg.add("PG12: ");
        pg.add("PG13: ");
        pg.add("PG14: ");
        pg.add("PG15: ");


        List<String> nur = new ArrayList<String>();
        nur.add("Object A ");
        nur.add("Obj B: ");
        nur.add("Obj C:");



        listDataChild.put(listDataHeader.get(0), pg); // Header, Child data
        listDataChild.put(listDataHeader.get(1), nur);

    }
}

可扩展列表适配器。java：

package com.lvexpandable;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Random;

import 安卓.content.Context;
import 安卓.content.SharedPreferences;
import 安卓.graphics.Typeface;
import 安卓.view.LayoutInflater;
import 安卓.view.View;
import 安卓.view.ViewGroup;
import 安卓.widget.BaseExpandableListAdapter;
import 安卓.widget.Button;
import 安卓.widget.EditText;
import 安卓.widget.TextView;
import 安卓.widget.Toast;

public class ExpandableListAdapter extends BaseExpandableListAdapter {


    private Context _context;
    private List<String> _listDataHeader; // header titles
    // child data in format of header title, child title
    private HashMap<String, List<String>> _listDataChild;






    public ExpandableListAdapter(Context context, List<String> listDataHeader,
                                 HashMap<String, List<String>> listChildData) {
        this._context = context;
        this._listDataHeader = listDataHeader;
        this._listDataChild = listChildData;

    }


    @Override
    public Object getChild(int groupPosition, int childPosititon) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .get(childPosititon);
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }



    @Override
    public View getChildView(int groupPosition, final int childPosition,
                             boolean isLastChild, View convertView, ViewGroup parent) {



        final String childText = (String) getChild(groupPosition, childPosition);

        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_item, null);
        }
        TextView txtListChild = convertView.findViewById(R.id.lblListItem);



        txtListChild.setText(childText);
        return convertView;
    }





    @Override
    public int getChildrenCount(int groupPosition) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .size();
    }

    @Override
    public Object getGroup(int groupPosition) {
        return this._listDataHeader.get(groupPosition);
    }

    @Override
    public int getGroupCount() {
        return this._listDataHeader.size();
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
                             View convertView, ViewGroup parent) {
        String headerTitle = (String) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_group, null);
        }

        TextView lblListHeader = (TextView) convertView
                .findViewById(R.id.lblListHeader);
        lblListHeader.setTypeface(null, Typeface.BOLD);
        lblListHeader.setText(headerTitle);

        return convertView;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }
}

主要活动。xml：

<?xml version="1.0" encoding="utf-8"?>
<安卓.support.constraint.ConstraintLayout xmlns:安卓="http://schemas.安卓.com/apk/res/安卓"
    xmlns:app="http://schemas.安卓.com/apk/res-auto"
    xmlns:tools="http://schemas.安卓.com/tools"
    安卓:layout_width="match_parent"
    安卓:layout_height="match_parent"
    tools:context="com.lvexpandable.MainActivity">

    <LinearLayout
        安卓:id="@+id/linearLayout"
        安卓:layout_width="match_parent"
        安卓:layout_height="match_parent"
        安卓:layout_marginBottom="8dp"
        安卓:layout_marginEnd="8dp"
        安卓:layout_marginStart="8dp"
        安卓:layout_marginTop="50dp"
        安卓:orientation="vertical"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <ExpandableListView
            安卓:id="@+id/lvExp"
            安卓:layout_width="match_parent"
            安卓:layout_height="400dp" />

        <Button
            安卓:onClick="btnClick"
            安卓:id="@+id/button"
            安卓:layout_width="wrap_content"
            安卓:layout_height="wrap_content"
            安卓:layout_marginStart="230dp"
            安卓:text="Button"
            tools:layout_editor_absoluteX="257dp"
            tools:layout_editor_absoluteY="360dp" />
    </LinearLayout>



</安卓.support.constraint.ConstraintLayout>

如果有人感到困惑，请随时提问：）

# 1 楼答案

您尝试做的事情当然是可能的，但很复杂：

在每个子项中添加一个按钮
当用户键入子项0时，他必须按下该子项的按钮（单击按钮时，将值保存在索引[childPosition]上的数组中）。在里面这样，数组[0]将具有子1的文本，与下一个类似孩子们

（步骤3和后续步骤是可选的）

如果您不喜欢这种设计（因为用户需要在每次输入值时按下按钮，请参阅步骤4）

将按钮（在步骤1中添加）的可见性设置为不可见

为ChildItem中的EditText添加TextWatcher（TextChangedListener）（当用户离开当前EditText时，它将获取输入的文本并将其保存在数组[]中并单击按钮本身）。作为：

edt.addTextChangedListener(new TextWatcher() { @Override public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {} @Override public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {} @Override public void afterTextChanged(Editable editable) { if(edt.getText().toString()==""&&edt.getText().toString().equals(null)){ } else { edt.setOnFocusChangeListener(new View.OnFocusChangeListener() { @Override public void onFocusChange(View v, boolean hasFocus) { if (!hasFocus)//Perform Click when edt loses Focus { btn.callOnClick(); } } }); } }});

现在，单击按钮将类似于：

btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { if(edt.getText().toString().equals("")){ } else { Toast.makeText(view.getContext(),"Entered: "+edt.getText().toString(),Toast.LENGTH_SHORT).show(); myStringArray[childPosition]=edt.getText().toString(); edt.setText(""); } } });

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java从可展开列表视图中的子级获取值

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# 1 楼答案