Android Interface Use Example

How we can use interface in Android application.

create activity_main.xml

<?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" >
    
    <EditText 
        android:id="@+id/edtname"
        android:layout_height="wrap_content"
        android:layout_width="fill_parent"
        android:hint="Enter name"/>
    <Button 
        android:id="@+id/btnadd"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:text="Add item"/>
    <ListView 
        android:id="@+id/lst"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:background="@android:color/black"></ListView>


</LinearLayout>

then create lstraw.xml for listview dynamic raw

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

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

    android:layout_width="wrap_content"

    android:layout_height="wrap_content"

    android:orientation="vertical" >

    <Button

        android:id="@+id/button1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignParentRight="true"

        android:layout_centerVertical="true"

        android:text="Delete" />

    <TextView

        android:id="@+id/textView1"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:layout_toLeftOf="@+id/button1"

        android:layout_centerVertical="true"

        android:text="TextView" />

</RelativeLayout>

below is MainActivity.java

package com.exampleinterfaceexample.act;

import java.util.ArrayList;

import android.app.Activity;

import android.os.Bundle;

import android.text.TextUtils;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.ListView;

public class MainActivity extends Activity{

ArrayList<String> myary;

ListView lst;

MyListAdapter mylstadp;

EditText edtname;

Button btnadd;

String strname;

@Override

protected void onCreate(Bundle savedInstanceState) {

// TODO Auto-generated method stub

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

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

edtname = (EditText)findViewById(R.id.edtname);

btnadd = (Button)findViewById(R.id.btnadd);

myary = new ArrayList<String>();

myary.add("Android");

myary.add("Iphone");

myary.add("Windows");

myary.add("Blackberry");

myary.add("Ipad");

mylstadp = new MyListAdapter(getApplicationContext(), myary);

lst.setAdapter(mylstadp);

mylstadp.setListeners(new MyInterface() {

@Override

public void rowDeleted(Integer pos) {

// TODO Auto-generated method stub

lst.removeViewAt(pos);

mylstadp.notifyDataSetChanged();

}

});

btnadd.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

strname = edtname.getText().toString();

if(!TextUtils.isEmpty(strname)){

myary.add(strname);

}

mylstadp.notifyDataSetChanged();

/*mylstadp = new MyListAdapter(getApplicationContext(), myary);

lst.setAdapter(mylstadp);*/

}

});

}

}

then create MyInterface.java class for interface

package com.exampleinterfaceexample.act;

public interface MyInterface {

   public abstract void rowDeleted(Integer pos);

}

then create listview adapter MyListAdapter.java

package com.exampleinterfaceexample.act;

import java.util.ArrayList;

import android.content.Context;

import android.content.Intent;

import android.text.TextUtils;

import android.view.LayoutInflater;

import android.view.View;

import android.view.View.OnClickListener;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.Button;

import android.widget.TextView;

public class MyListAdapter extends BaseAdapter {

Context mContext;

LayoutInflater layoutinflator;

ArrayList<String> araylistatende;

MyInterface myinterface;

public MyListAdapter(Context context, ArrayList<String> list) {

this.araylistatende = list;

this.mContext = context;

this.layoutinflator = LayoutInflater.from(context);

}

@Override

public int getCount() {

// TODO Auto-generated method stub

return araylistatende.size();

}

@Override

public Object getItem(int position) {

// TODO Auto-generated method stub

return araylistatende.get(position);

}

@Override

public long getItemId(int position) {

// TODO Auto-generated method stub

return position;

}

@Override

public View getView(final int position, View view, ViewGroup parent) {

// TODO Auto-generated method stub

if (view == null) {

view = layoutinflator.inflate(R.layout.lstraw, null);

}

TextView txteventpasttype = (TextView) view.findViewById(R.id.textView1);

Button btn = (Button)view.findViewById(R.id.button1);

if(araylistatende.get(position) != null){

txteventpasttype.setText(araylistatende.get(position).toString());

}

btn.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

araylistatende.remove(position);

notifyDataSetChanged();

}

});

return view;

}

// This is the interface method

public void setListeners(MyInterface  datasend)

{

myinterface = datasend;  

}

// This is the interface method

}

Now ,run the code.

This code is define the use of interface is android application.