Question

So for this I am trying to take 2 integer values the user inputs in the 2 EditTexts provided in the main activity and add them together. Then, I want the android application to switch to the 2nd Activity and in the EditText box there display the sum of the 2 values entered into the 2 EditText boxes from the previous(main) Activity.

I think I’m on the right track, but I’m not quite certain how to obtain the sum in the second activity. I’ve tried messing with bundles and such, but I still can’t quite figure it out.

**Re-edited to reflect some suggestions. The 2nd activity still does not show the total…I’m thinking it’s a conversion error of some sort.

***I’m almost positive it has something to do with the 2nd Activity..the first looks right to me

**PERFECT! It was a conversion error. Thanks all for the help 😀

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;


public class MainActivity extends Activity 
{   

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

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

    public void OnClick(View v) //android:onClick="OnClick"   added to activity_main.xml for this button
    {
        Intent intent = new Intent(MainActivity.this, Summation.class);
    EditText v1 = (EditText)findViewById(R.id.editText1);
    EditText v2 = (EditText)findViewById(R.id.editText2);   
    int first =  Integer.parseInt(v1.getText().toString());
    int second = Integer.parseInt(v2.getText().toString());
    String sum = String.valueOf(first + second);
    intent.putExtra("sum", sum);
    startActivity(intent);          
    }
}

Second Activity Class

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.EditText;

public class Summation extends Activity 
{
    //Second Activity 

    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_2);        
        String sum = (getIntent().getExtras().getString("sum"));
        EditText addsum = (EditText)findViewById(R.id.editText1);
        addsum.setText(sum);

    }   
}

Answer 1

You can’t assign your int value straight from edittext. You need to assign the edit texts like

EditText eText1 = (EditText) findViewById(R.id.yourfirstedittext)

and the same with your second. Then get the values

int firstNum = Integer.parseInt(eText1.getValue.toString())

and of course the same with the second. You can then add these two ints together and simply pass them with intent.putExtra("sume, sum). Then get them in your second Activity with getIntent()

Intent ci = getIntent();
final int sum = ci.getIntExtra("sum", yourDefaultIntValue)

If you are passing as an int you will need to do it this way and get the String value of the int. But if you pass as a String then you are fine