Simple Adapter & Hashmap

In this tutorial, I will show you how to use hashmap and simple adapter. See output below!

Here's the activity_main.xml codes below.

<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:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".MainActivity" >

    <ListView

        android:id="@+id/lv_sample"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:layout_alignParentLeft="true"

        android:layout_alignParentTop="true" >

    </ListView>

</RelativeLayout>

Here's the content.xml codes below.

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical" >

    <TextView

        android:id="@+id/tv_content"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:textColor="#000000"

        android:text="Content" />

</LinearLayout>

Actually I have 3 ways here to output that, using ArrayAdapter, SimpleAdapter, & ListAdapter. See codes below.

Using Simple Adapter

package com.example.arrayadapter;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import android.app.Activity;

import android.content.Context;

import android.os.Bundle;

import android.util.Log;

import android.view.LayoutInflater;

import android.view.Menu;

import android.view.View;

import android.view.ViewGroup;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;

import android.widget.ArrayAdapter;

import android.widget.ListView;

import android.widget.SimpleAdapter;

import android.widget.TextView;

import android.widget.Toast;

public class MainActivity extends Activity {

ListView lv_sample;

Adapter adapters;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

initializeVars();

ArrayList<HashMap<String, String>> list = new ArrayList<HashMap<String,String>>();

String[] values = new String[] { "Android List View", 

                "Adapter implementation",

                "Simple List View In Android",

                "Create List View Android", 

                "Android Example", 

                "List View Source Code", 

                "List View Array Adapter", 

                "Android Example List View" 

               };

for(int x=0; x<=7; x++){

HashMap<String, String> map = new HashMap<String, String>();

map.put("key", values[x]);

list.add(map);

}

adapters = new Adapter(getApplicationContext(), list, R.layout.content, 

        new String[] { "key" },

                new int[] { R.id.tv_content});

  // Define a new Adapter

        // First parameter - Context

        // Second parameter - Layout for the row

        // Third parameter - ID of the TextView to which the data is written

        // Forth - the Array of data

        //ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,

        //  R.layout.content, R.id.tv_content, values);s

        

        lv_sample.setAdapter(adapters);

        

        lv_sample.setOnItemClickListener(new OnItemClickListener() {

@Override

public void onItemClick(AdapterView<?> arg0, View arg1, int position,

long arg3) {

// TODO Auto-generated method stub

ListView lv = (ListView) arg0;

                TextView key=(TextView)arg0.getChildAt(position-lv.getFirstVisiblePosition()).findViewById(R.id.tv_content);

// Show Alert 

                Toast.makeText(getApplicationContext(), key.getText().toString() , Toast.LENGTH_LONG)

                  .show();

}

});

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

public void initializeVars(){

lv_sample = (ListView)findViewById(R.id.lv_sample);

}

}

class Adapter extends SimpleAdapter{

private Context mcontext;

public Adapter(Context context, List<? extends Map<String, ?>> data,

int resource, String[] from, int[] to) {

super(context, data, resource, from, to);

// TODO Auto-generated constructor stub

mcontext = context;

}

@SuppressWarnings("unchecked")

@Override

   public View getView(int position, View convertView, ViewGroup parent) {

    LayoutInflater object = (LayoutInflater)mcontext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

      if (convertView == null) 

      {

               convertView = object.inflate(R.layout.content,

                      null);

          }

          HashMap<String, String> data = (HashMap<String, String>) getItem(position);

          

          

          ((TextView) convertView.findViewById(R.id.tv_content)).setText((String) data.get("key"));

          return convertView;

}

}

Using ListAdapter

package com.example.arrayadapter;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import android.app.Activity;

import android.content.Context;

import android.os.Bundle;

import android.util.Log;

import android.view.LayoutInflater;

import android.view.Menu;

import android.view.View;

import android.view.ViewGroup;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;

import android.widget.ArrayAdapter;

import android.widget.ListAdapter;

import android.widget.ListView;

import android.widget.SimpleAdapter;

import android.widget.TextView;

import android.widget.Toast;

public class MainActivity extends Activity {

ListView lv_sample;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

initializeVars();

ArrayList<HashMap<String, String>> list = new ArrayList<HashMap<String,String>>();

String[] values = new String[] { "Android List View", 

                "Adapter implementation",

                "Simple List View In Android",

                "Create List View Android", 

                "Android Example", 

                "List View Source Code", 

                "List View Array Adapter", 

                "Android Example List View" 

               };

for(int x=0; x<=7; x++){

HashMap<String, String> map = new HashMap<String, String>();

map.put("key", values[x]);

list.add(map);

}

ListAdapter adapters = new SimpleAdapter(getApplicationContext(), list, R.layout.content, 

        new String[] { "key" },

                new int[] { R.id.tv_content});

  // Define a new Adapter

        // First parameter - Context

        // Second parameter - Layout for the row

        // Third parameter - ID of the TextView to which the data is written

        // Forth - the Array of data

        //ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,

        //  R.layout.content, R.id.tv_content, values);s

        

        lv_sample.setAdapter(adapters);

        

        lv_sample.setOnItemClickListener(new OnItemClickListener() {

@Override

public void onItemClick(AdapterView<?> arg0, View arg1, int position,

long arg3) {

// TODO Auto-generated method stub

ListView lv = (ListView) arg0;

                TextView key=(TextView)arg0.getChildAt(position-lv.getFirstVisiblePosition()).findViewById(R.id.tv_content);

// Show Alert 

                Toast.makeText(getApplicationContext(), key.getText().toString() , Toast.LENGTH_LONG)

                  .show();

}

});

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

public void initializeVars(){

lv_sample = (ListView)findViewById(R.id.lv_sample);

}

}

Using ArrayAdapter

package com.example.arrayadapter;

import android.app.Activity;

import android.os.Bundle;

import android.view.Menu;

import android.view.View;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;

import android.widget.ArrayAdapter;

import android.widget.ListView;

import android.widget.Toast;

public class MainActivity extends Activity {

ListView lv_sample;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

initializeVars();

String[] values = new String[] { "Android List View", 

                "Adapter implementation",

                "Simple List View In Android",

                "Create List View Android", 

                "Android Example", 

                "List View Source Code", 

                "List View Array Adapter", 

                "Android Example List View" 

               };

  // Define a new Adapter

           // First parameter - Context

           // Second parameter - Layout for the row

           // Third parameter - ID of the TextView to which the data is written

           // Forth - the Array of data

        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,

          R.layout.content, R.id.tv_content, values);

        

        lv_sample.setAdapter(adapter);

        

        lv_sample.setOnItemClickListener(new OnItemClickListener() {

@Override

public void onItemClick(AdapterView<?> arg0, View arg1, int position,

long arg3) {

// TODO Auto-generated method stub

int itemPosition = position;

String itemValue = (String)lv_sample.getItemAtPosition(itemPosition);

// Show Alert 

                Toast.makeText(getApplicationContext(),

                  "Position :"+itemPosition+"  ListItem : " +itemValue , Toast.LENGTH_LONG)

                  .show();

}

});

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

public void initializeVars(){

lv_sample = (ListView)findViewById(R.id.lv_sample);

}

}

That's it, I hope this simple tutorial may help you a lot. Happy Coding!