Multiple Buttons' OnClickListener() android

Question

I'm currently making a simple calculator app on Android. Im trying to set up the code so that when a number button is pressed it updates the calculator screen with that number. Currently I'm doing it like this.

    Button one = (Button) findViewById(R.id.oneButton);
    one.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            TextView output = (TextView) findViewById(R.id.output);
            output.append("1");
        }
    });

It works but I'm writing this same code for every single button on the calculator. As you can imagine it is very redundant. Is there anyway I can write this code in a more efficient way? One that involves not writing this method for every single button?

implement the onclick listener in your class,it will override onclick method.Based on button id you can make operations — learner, Sep 18 '14 at 05:55
Boopathi, can you explain more on how I would then code the one button? I made the button id "1" that way I can use "this" to access the number. Im not sure how I would then edit the TextView though. — user3011685, Sep 18 '14 at 06:04

Pragnesh Ghoda シ · Accepted Answer · 2023-02-02T13:49:09.623

258

You Just Simply have to Follow these steps for making it easy...

You don't have to write new onClickListener for Every Button... Just Implement View.OnClickLister to your Activity/Fragment.. it will implement new Method called onClick() for handling onClick Events for Button,TextView` etc.

Implement OnClickListener() in your Activity/Fragment

public class MainActivity extends Activity implements View.OnClickListener {

}

Implement onClick() method in your Activity/Fragment

public class MainActivity extends Activity implements View.OnClickListener {
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }
    
    @Override
    public void onClick(View v) {
      // default method for handling onClick Events..
    }
}

Implement OnClickListener() For Buttons

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    
    setContentView(R.layout.your_layout);
    
    Button one = (Button) findViewById(R.id.oneButton);
    one.setOnClickListener(this); // calling onClick() method
    Button two = (Button) findViewById(R.id.twoButton);
    two.setOnClickListener(this);
    Button three = (Button) findViewById(R.id.threeButton);
    three.setOnClickListener(this);
}

Find Buttons By Id and Implement Your Code..

@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.oneButton:
            // do your code
            break;
        case R.id.twoButton:
            // do your code
            break;
        case R.id.threeButton:
            // do your code
            break;
        default:
            break;
    }
}

Please refer to this link for more information :

This will make it easier to handle many buttons click events and makes it looks simple to manage it...

edited Feb 02 '23 at 13:49

answered Sep 18 '14 at 06:07

Pragnesh Ghoda シ

8,318
3
25
40

Point 4: I am getting error on @Override tag which warns me that method does not override its method from superclass. – KasparTr Feb 23 '16 at 12:59
@user2984127 try implementing View.OnClickListener. – Pragnesh Ghoda シ Mar 02 '16 at 10:43
I used this method many times while using Eclipse, but now I switched to Android Studio and I get an error "Resource IDs cannot be used in a switch statement in Android library modules.". As of SDK tools R14 the Resource IDs are not final. The recommended fix is to replace the switch with if/else statements. – Scorpio Mar 11 '16 at 08:53
@Scorpio : I am using android studio too. But I never got that error. Please check that you are using proper methods and with using `view.getId()`, you are getting ID of clicked button. This is an example, you have make some changes depends on your need. Cheers. :) – Pragnesh Ghoda シ Apr 08 '16 at 06:01
is there any way to avoid the setting on onClickListener on each button?? I mean, if I have a large no. of buttons from which I need to listen the click events, then the code looks dirty and its tedious to write listener for each button like :button1.setOnClickListener(this);button2.setOnClickListener(this);.... buttonN.setOnClickListener(this); I there any way to avoid this?? android:onClick attribute in the layout will solve this purpose but I want something in Java source code. – srv_sud Apr 11 '16 at 18:01
@Scorpio is correct in case your listener is part of a library (not in case of an app). Then you can't use the id's in a switch case since they're not final (and so, not a constant) anymore since API 14. You have to use the (more ugly) if-else if construction. A pity... – GeertVc Oct 31 '17 at 06:53
@PragneshGhodaシ How we can do this in RecyclerView? – Ahmet Yılmaz Jul 09 '19 at 15:08
@AhmetYılmaz In that case you need to create listener and implement onClick in the ViewHolder. Please follow this link for more info : https://androidacademic.blogspot.com/2016/12/recyclerview-item-onclicklistener.html – Pragnesh Ghoda シ Jul 10 '19 at 08:54
1

@PragneshGhodaシ thanks for answer. I solved it after I asked in stackOverflow. https://stackoverflow.com/questions/56965159/how-can-add-same-onclick-for-all-imageview-in-recyclerview/56965409?noredirect=1#comment100470609_56965409 – Ahmet Yılmaz Jul 10 '19 at 09:29

Andro · Answer 2 · 2018-04-15T20:52:48.313

59

You could set the property:

android:onClick="buttonClicked"

in the xml file for each of those buttons, and use this in the java code:

public void buttonClicked(View view) {

    if (view.getId() == R.id.button1) {
        // button1 action
    } else if (view.getId() == R.id.button2) {
        //button2 action
    } else if (view.getId() == R.id.button3) {
        //button3 action
    }

}

edited Apr 15 '18 at 20:52

answered Sep 18 '14 at 05:59

Andro

952
9
19

4

better to use switch – Ali Khaki Jan 14 '19 at 19:08
1

@AliKhaki `switch` might not work in some cases. Explained here: http://tools.android.com/tips/non-constant-fields – Andro Jan 23 '19 at 15:26

score 11 · Answer 3 · answered Sep 18 '14 at 07:53

Set a Tag on each button to whatever you want to work with, in this case probably an Integer. Then you need only one OnClickListener for all of your buttons:

Button one = (Button) findViewById(R.id.oneButton);
Button two = (Button) findViewById(R.id.twoButton);
one.setTag(new Integer(1));
two.setTag(new Integer(2));

OnClickListener onClickListener = new View.OnClickListener() {

    @Override
    public void onClick(View v) {
        TextView output = (TextView) findViewById(R.id.output);
        output.append(v.getTag());
    }
}

one.setOnClickListener(onClickListener);
two.setOnClickListener(onClickListener);

See also [this answer](http://stackoverflow.com/a/5291891/667253) on what to use Tags for — Henrik Christensen, Sep 18 '14 at 07:58

score 9 · Answer 4 · answered Feb 15 '15 at 02:03

9

I created dedicated class that implements View.OnClickListener.

public class ButtonClickListener implements View.OnClickListener {

    @Override
    public void onClick(View v) {
        Toast.makeText(MainActivity.this, "Button Clicked", Toast.LENGTH_SHORT).show();
    }

}

Then, I created an instance of this class in MainActivity

private ButtonClickListener onClickBtnListener = new ButtonClickListener();

and then set onClickListener for button

btn.setOnClickListener(onClickBtnListener);

answered Feb 15 '15 at 02:03

Vadim Novitskiy

179
2
11

that work, but if you use more than one button you will call always the same Listener, you should add a switch case in your method onClick with the id of each button. – lebarillier Dec 05 '18 at 05:37
I'm assuming if you create a class instance per button that would also alleviate this concern – Matt Strom Apr 26 '20 at 22:16

score 3 · Answer 5 · edited Jan 23 '17 at 07:36

public class MainActivity extends AppCompatActivity implements OnClickListener  {
    Button  b1,b2;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        b1= (Button) findViewById(R.id.button);
        b2= (Button) findViewById(R.id.button2);
        b1.setOnClickListener(this);
        b2.setOnClickListener(this);
    }


    @Override
    public void onClick(View v)
    {
        if(v.getId()==R.id.button)
        {
            Intent intent=new Intent(getApplicationContext(),SignIn.class);
            startActivity(intent);
        }
        else if (v.getId()==R.id.button2)
        {
            Intent in=new Intent(getApplicationContext(),SignUpactivity.class);
            startActivity(in);
        }
    }
}

score 2 · Answer 6 · answered Jul 01 '16 at 12:08

I had a similar issue and what I did is: Create a array of Buttons

Button buttons[] = new Button[10];

Then to implement on click listener and reference xml id's I used a loop like this

for (int i = 0; i < 10; i++) {      
String buttonID = "button" + i;
        int resID = getResources().getIdentifier(buttonID, "id",
                "your package name here");
        buttons[i] = (Button) findViewById(resID);
        buttons[i].setOnClickListener(this);
    }

But calling them up remains same as in Prag's answer point 4. PS- If anybody has a better method to call up all the button's onClick, please do comment.

score 1 · Answer 7 · edited Mar 17 '19 at 14:57

You can use this

    TextView output = (TextView) findViewById(R.id.output);
    one.setOnClickListener(youractivity.this);
    // set the onclicklistener for other buttons also

    @Override
    public void onClick(View v) {
      int id = v.getId();
    switch(id) {
    case R.id.oneButton:      
       append("1",output);
       break;
    case R.id.twoButton:
        append("2",output);
       break;
    case R.id.threeButton:
        append("3",output);
       break;
     } 
      }

 private void append(String s,TextView t){
  t.setText(s); 
}

you can identify the views in your activity in a separate method.

score 1 · Answer 8 · edited Dec 14 '19 at 22:37

Implement onClick() method in your Activity/Fragment public class MainActivity extends Activity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public void onClick(View v) {
 switch (itemId) {

// if you call the fragment with nevigation bar then used.

           case R.id.nav_menu1:
                fragment = new IntroductionFragment();
                break;

// if call activity with nevigation bar then used.

            case R.id.nav_menu6:
                Intent i = new Intent(MainActivity.this, YoutubeActivity.class);
                startActivity(i);
      // default method for handling onClick Events..
    }
}

score 1 · Answer 9 · answered Feb 01 '17 at 06:59

public void onClick(View v) {
    int id = v.getId();
    switch (id){
        case R.id.button1:
            //do ur code
            Toast.makeText(this,"This is button 1",Toast.LENGTH_SHORT).show();
            break;
        case R.id.button2:
            Intent intent = new Intent(this,SecondActivity.class);
            Intent.putExtra("key",value);
            startActivity(intent);
            break;
        case R.id.button3:
            //do ur code
            break;
        case R.id.button4:
            //do ur code;
            break;
        default:
            //do ur code;
    }
}

score 0 · Answer 10 · answered May 16 '19 at 23:19

I find that using a long if/else chain (or switch), in addition to the list of findViewById(btn).setOnClickListener(this) is ugly. how about creating new View.OnlickListeners with override, in-line:

findViewById(R.id.signInButton).setOnClickListener(new View.OnClickListener()
    { @Override public void onClick(View v) { signIn(); }});
findViewById(R.id.signOutButton).setOnClickListener(new View.OnClickListener()
    { @Override public void onClick(View v) { signOut(); }});
findViewById(R.id.keyTestButton).setOnClickListener(new View.OnClickListener()
    { @Override public void onClick(View v) { decryptThisTest(); }});
findViewById(R.id.getBkTicksButton).setOnClickListener(new View.OnClickListener()
    { @Override public void onClick(View v) { getBookTickers(); }});
findViewById(R.id.getBalsButton).setOnClickListener(new View.OnClickListener()
    { @Override public void onClick(View v) { getBalances(); }});

score 0 · Answer 11 · edited Jan 08 '23 at 02:24

0

No need of if else's or switch, Let's start: In your every Button or whatever it is (I am using ImageView), Add this attribute android:onClick="DoSomeThing"

In your Activity:

public void DoSomeThing(View v){
    ImageView img1= (ImageView) v; //you have to cast the view i.e. if it's button, it must be cast to Button like below line

    Button b1= (Button) v;

    img1.setImageBitmap(imageBitmap); //or anything you want to do with your view, This will work for all

    b1.setText("Some Text");
}

In this way, no need to find views by id, no click listeners, no redundant code, simple as above!

edited Jan 08 '23 at 02:24

Cody Gray - on strike

239,200
50
490
574

answered Sep 01 '20 at 03:24

Zubair Younas

71
1
13

In this way, no need to find views by id, no click listeners, no redundant code, simple as above! – Zubair Younas Sep 01 '20 at 03:26

Lance Samaria · Answer 12 · 2023-04-25T04:33:35.487

I needed one function for multiple buttons using view binding, not findViewById.

1- In the code below each button's setOnClickListener calls the same function btnTapped which has a parameter that takes in a view.

2- btnTapped runs a switch statement on the view parameter and Toasts whichever button was tapped.

3- When each button's setOnClickListener is set, I pass in it which is the view/button itself

Sample calculator with buttons 7,8,9

private lateinit var binding: ActivityMainBinding

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)

    binding = ActivityMainBinding.inflate(layoutInflater)
    setContentView(binding.root)

    setOnClickListeners()
}

private fun setOnClickListeners() {

    // "it" is the view/button itself
    binding.btnSeven.setOnClickListener { btnTapped(it) }
    binding.btnEight.setOnClickListener { btnTapped(it) }
    binding.btnNine.setOnClickListener { btnTapped(it) }
}

private fun btnTapped(view: View) {

    // run a switch statement to do something when each button is pressed
    when (view) {
        binding.btnSeven -> showToast("7 tapped")
        binding.btnEight -> showToast("8 tapped")
        binding.btnNine -> showToast("9 tapped")
        else -> showToast("something else tapped")
    }
}

private fun showToast(text: String) {
    Toast.makeText(this, text, Toast.LENGTH_LONG).show()
}

Multiple Buttons' OnClickListener() android

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