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

 

  
  
 
 

  
  
 

 
 

  
  
 

package com.example.hjw.calculator;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
 private TextView tv1,tv2;
 private EditText edt1,edt2;
 private Button btn;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  btn=(Button)this.findViewById(R.id.btn);
  edt1=(EditText)this.findViewById(R.id.edit1);
  edt2=(EditText)this.findViewById(R.id.edit2);
  tv1=(TextView)this.findViewById(R.id.text1);
  btn.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View v) {
    String inputText1=edt1.getText().toString();
    String inputText2=edt2.getText().toString();
    int num1=Integer.valueOf(inputText1).intValue();
    int num2=Integer.valueOf(inputText2).intValue();
    num1=num1+num2;
    inputText1=String.valueOf(num1);
    tv1.setText(inputText1);
   }
  });
 }
}