Question

Hi I am developing an Android app using an EditText, and a add en minus button to control it’s value.
I got it working now, but I wanna repeat it to multiple values. I know I can just repeat the code with different variables but the code would big really large.

Anyone an idea how to repeat the same code for multiple values?

This is my current code:

package com.lars.MyApp;

import com.lars.MyApp.R;

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


public class MyAppActivity extends Activity {

    int currentValue = 0;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        final EditText Value = (EditText) findViewById(R.id.Value);
        Button addButton = (Button) findViewById(R.id.addButton);
        Button minusButton = (Button) findViewById(R.id.minusButton);

        addButton.setOnClickListener(new OnClickListener(){

            public void onClick(View v) {
                addValue();
                Value.setText("" + currentValue);
            }

        });

        minusButton.setOnClickListener(new OnClickListener(){

            public void onClick(View v) {
                minusValue();
                Value.setText("" + currentValue);
            }

        });


    }

    public void addValue(){
        if(currentValue <= 999){
        currentValue = currentValue + 1;
        }
    }  

    public void minusValue(){
        if(currentValue >= 1){
            currentValue = currentValue - 1;
        }
    }  

}

Answer 1

You should refactor your OnClickListeners so that they are generic. Probably the easiest way to do this is to change your addValue() method to be addValue(View v), and minusValue() to minusValue(View v). Then, in the layout xml, you add a property android:onClick=addValue or android:onClick=minusValue. You’ll have to update the method bodies so that they check the view’s id and do the right thing based on that, but you won’t have to create and set a whole bunch of OnClickListeners in the onCreate method – you’ll get that for free.