Hello, hello; i'm a new android developer, I want to make an app where a user enter a matrix A and a vector b of the same lenght and my app will print x vector, for Ax=b! But I don't know how to collect the values typed by the user, nor how to save variables in main.xml! Can someone help me please?

If you're looking to keep this as simple as possible, you will probably do something like have the user put the data in through EditText boxes and print out via a TextView somewhere on the screen. I've thrown together an absolute bare minimum app that simply adds two integers together as an example.

The XML is fairly obvious :

Code: Select all

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView 
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Sum Here"
    android:gravity="center_horizontal"
    android:id="@+id/SumText"/>
<EditText android:id="@+id/Num1Field"
   android:layout_height="wrap_content"
   android:layout_gravity="center_horizontal"
   android:layout_width="150dp"
   android:hint="Num 1 Here"></EditText>
<EditText android:id="@+id/Num2Field"
   android:layout_height="wrap_content"
   android:layout_gravity="center_horizontal"
   android:layout_width="150dp"
   android:hint="Num 2 Here"></EditText>
<Button android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_gravity="center_horizontal"
   android:text="Add!"
   android:id="@+id/AddButton"></Button>
</LinearLayout>


And the actual Java code is simply :

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package net.shattered9.EditTextTest;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class EditTextTest extends Activity {
   
   TextView sumView;
   EditText number1;
   EditText number2;
   int num1;
   int num2;
        int sum;

   
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        Button addButton = (Button)findViewById(R.id.AddButton);
        addButton.setOnClickListener(new OnClickListener() {
         
         @Override
         public void onClick(View v) {
            sumView = (TextView)findViewById(R.id.SumText);
            number1 = (EditText)findViewById(R.id.Num1Field);
            number2 = (EditText)findViewById(R.id.Num2Field);
            num1 = Integer.parseInt(number1.getText().toString());
            num2 = Integer.parseInt(number2.getText().toString());
            sum = num1 + num2;
            sumView.setText(num1 + " + " + num2 + " = " + sum);
         }
      });     
    }
}

Obviously this is over simplified, and even a tad buggy (Never checks to see that what was entered were ints), but it gives the most basic way to get the values out. Of course in yours you will not simply be adding two numbers, and if I recall anything about working with matrices and vectors (Probably not, it's been a while ) you will also be using Floats instead of Integers. Hopefully this gives you some basic idea though.

Oh so sorry, i didn't know a that an answer for my question had been post!! i'll try to understand all this code and will make u know soon! Thanks a loooot!!

great, so helpful! i have seen a matrix android object in developer.android.com maybe I wont need to put as many textView and EditText as my matrix size! Else it seems to be laborious!!! Thanks again...
Regards