how to link two resource files in android studio?

Question

make activity with 2 resource files (or 2 layouts). 1 containg form to retrieve arraylist from database and 2nd to show that list in list view.. how to link these two resource files? i want to use inflator.. but don't know where to use it? after setting adapter or before calling the getter in onclick() here is what i've tried:

MainActivity.java

package com.example.bsitn_000.datalist;

import android.app.Activity;
import android.app.ListActivity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.Toast;

import java.util.ArrayList;

public class MainActivity extends Activity implements View.OnClickListener {

    private RelativeLayout layoutToAdd;
    EditText NoP;
    EditText eTime;
    EditText lTime;
    EditText date;
    Button check;

    ListView listView;
    ArrayAdapter<String> adapter;

    ArrayList<String> ResList;

    protected SQLiteDatabase db;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        layoutToAdd = (RelativeLayout)findViewById(R.id.existedlayout);

        createDatabase();

        NoP = (EditText)findViewById(R.id.editText4);
        eTime = (EditText)findViewById(R.id.editText);
        lTime = (EditText)findViewById(R.id.editText2);
        date = (EditText)findViewById(R.id.editText3);

        listView = (ListView)findViewById(R.id.list_view);

        check =(Button)findViewById(R.id.button);
        check.setOnClickListener(this);

    }

    public void createDatabase() {
        db = openOrCreateDatabase("Restaurant.db", Context.MODE_PRIVATE,null);
        db.execSQL("CREATE TABLE IF NOT EXISTS reserve(id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, " +
                " NoP Text, eTime Text, lTime Text, date Text, res Text);");
    }

    public ArrayList<String> getResList(){
        String n = NoP.getText().toString();
        String e = eTime.getText().toString();
        String l = lTime.getText().toString();
        String d = date.getText().toString();
        ResList = new ArrayList<String>();

        String query = "SELECT res FROM reserve WHERE NoP = '"+n+"' AND eTime = '"+e+"'AND lTime = '"+l+"'AND date = '"+d+"'";
        Cursor cursor = db.rawQuery(query,null);
        if (cursor.moveToFirst()){
            do {
                ResList.add(cursor.getString(cursor.getColumnIndex("res")));
            }while (cursor.moveToNext());

        }
        return ResList;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    private void callingMore(){
        LayoutInflater inflater = LayoutInflater.from(getApplicationContext());
        View view = inflater.inflate(R.layout.activity_mylist,null);
        layoutToAdd.addView(view);
    }


    @Override
    public void onClick(View v) {
        if (v == check){
            getResList();
            if (ResList.size()!=0){
                adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,ResList);
                listView.setAdapter(adapter);
                callingMore();
            }
            else {
                Toast.makeText(this,"no record",Toast.LENGTH_SHORT).show();

            }
        }

    }
}

activity_main.xml

<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" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
    android:id="@+id/existedlayout">

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/editText"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:inputType="text"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_marginTop="40dp" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/editText2"
        android:layout_below="@+id/editText"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:inputType="text"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/editText3"
        android:layout_below="@+id/editText2"
        android:layout_alignRight="@+id/editText2"
        android:layout_alignEnd="@+id/editText2"
        android:inputType="text"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/c"
        android:id="@+id/button"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:background="#bbff99" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="number"
        android:ems="10"
        android:id="@+id/editText4"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignRight="@+id/editText"
        android:layout_alignEnd="@+id/editText" />
</RelativeLayout>

activity_mylist.xml

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

    <ListView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/listView"
        android:layout_gravity="center_horizontal" />
</LinearLayout>

Answer 1

I think you want one layout after filling up the data in the edit text and hitting the submit button. If so, you can priorly set the layout activity_main.xml on first when activity is created i.e. onCreate and once you fill and hit the submit button change the layout on click of button i.e. activity_mylist.xml

e.g.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Button btnSubmit = (Button) findViewById(R.id.button);

    btnSubmit.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

           setContentView(R.layout.activity_list);
           ListView lv = (ListView) findViewById(R.id.listView);
        }     

}

This is inappropriate but if you want to use it this way only then you can proceed. Ideally you should make two different activity and on button click you should move to new activity with help of Intent. Hope this helps.

Answer 2

To specifically answer your question of where you should inflate the ListView, you should inflate the ListView before setting the adapter.

Since the inflation is done in callingMore(), instead of invoking callingMore() after listView.setAdapter(adapter);, you should invoke it before setting the adapter as shown below.

    @Override
    public void onClick(View v) {
        if (v == check){
            ResList = getResList();
            if (ResList.size()!=0){
                callingMore();
                adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,ResList);
                listView = (ListView) findViewById(R.id.listView);
                listView.setAdapter(adapter);
            }
            else {
                Toast.makeText(this,"no record",Toast.LENGTH_SHORT).show();
            }
        }

It also seems that you have forgotten to set listView = (ListView) findViewById(R.id.listView); before calling listView.setAdapter(adapter);. This will cause a NullPointerException and might be why you were confused as to where you should do the inflation. You can only get a reference to your ListView with the id R.id.listView after it has been inflated.

You also forgot to assign the return value of getResList() to ResList. It should be ResList = getResList(); instead of just getResList();

Also, there might be a typo in onCreate(), listView = (ListView)findViewById(R.id.list_view);. You probably meant listView = (ListView)findViewById(R.id.listView); instead.

Oh and in callingMore() the two lines,

View view = inflater.inflate(R.layout.activity_mylist,null);
layoutToAdd.addView(view);

can be replaced with just View view = inflater.inflate(R.layout.activity_mylist, layoutToAdd); since putting layoutToAdd in the second parameter sets it as the parent view of view.