Question

I have made an application in that i have an activity contains a TextView and a button.Now this activity is used multiple times in the application so i want is that when i click the back button in that activity ,it should go to the previous activity.In short it should work as back button of device.My code is as below:

this activity is used in 4 activities ,

So i have tried as below:

Advance_help.java

package com.theappgeeks.kevingreenwealth;

import java.text.BreakIterator;

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

public class AdvanceHelp extends Activity implements OnClickListener{
Button btn;
Calculator_1Activity cal1 =new Calculator_1Activity();
Calculator2 cal2 =new Calculator2();
Calculator_3Activity cal3 =new Calculator_3Activity();
Calculator_4Activity cal4 =new Calculator_4Activity();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_advance_help);
        btn=(Button)findViewById(R.id.button1);
        /*btn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                if(btn.)
            Intent i1=new Intent(AdvanceHelp.this,Calculator_1Activity.class);  
            startActivity(i1);

            }
        });*/
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_advance_help, menu);
        return true;
    }

    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        if(v.equals(cal1)){
            btn.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    Intent i1= new Intent(AdvanceHelp.this,Calculator_1Activity.class);
                    startActivity(i1);
                }

            });

        }
        else if(v.equals(cal2)){
            btn.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    Intent i1= new Intent(AdvanceHelp.this,Calculator2.class);
                    startActivity(i1);
                }

            });

        }

        else if(v.equals(cal3)){
            btn.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    Intent i1= new Intent(AdvanceHelp.this,Calculator2.class);
                    startActivity(i1);
                }

            });

        }

        else if(v.equals(cal4)){
            btn.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub
                    Intent i1= new Intent(AdvanceHelp.this,Calculator2.class);
                    startActivity(i1);
                }

            });

        }
        else
        {
            Intent i = new Intent(AdvanceHelp.this,MainMenuActivity.class);
            startActivity(i);
        }
    }
}

Please help me as soon as possible..thank you
in advance

Answer 1

Bad programming practice,

As you already implements OnClickListener

btn=(Button)findViewById(R.id.button1);
btn.setOnClickListener(this);

and remove

 btn.setOnClickListener(new OnClickListener() {

from

@Override
    public void onClick(View v) {

And for

i want is that when i click the back button in that activity ,it should go to the previous
activity.In short it should work as back button of device.My code is as below:

Just call Activity’s finish() in button’s click() on which you want..