how to add button click event in android studio

JavaAndroidButtonViewAndroid Studio

Java Problem Overview

So I have done some research, and after defining you button as an object by the code

private Button buttonname;
buttonname = (Button) findViewById(R.id.buttonnameinandroid) ;

here is my problem

buttonname.setOnClickListener(this); //as I understand it, the "**this**" denotes the current `view(focus)` in the android program

then your OnClick() event...

Problem:

When I type in the "this", it says:

setOnClickListener (Android.View.view.OnClickListener) in View cannot be applied to (com.helloandroidstudio.MainActivity)

I have no idea why?

here is the code from the .java file

import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

    private Button btnClick;
    private EditText Name, Date;
    private TextView msg, NameOut, DateOut;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btnClick = (Button) findViewById(R.id.button) ;
        btnClick.setOnClickListener(this);
        Name = (EditText) findViewById(R.id.textenter) ;
        Date = (EditText) findViewById(R.id.editText) ;
        msg = (TextView) findViewById(R.id.txtviewOut) ;
        NameOut = (TextView) findViewById(R.id.txtoutName) ;
        DateOut = (TextView) findViewById(R.id.txtOutDate) ;
        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }
    }

    public void onClick(View v)
    {
        if (v == btnClick)
        {
            if (Name.equals("") == false && Date.equals("") == false)
            {
                NameOut = Name;
                DateOut = Date;
                msg.setVisibility(View.VISIBLE);
            }
            else
            {
                msg.setText("Please complete both fields");
                msg.setVisibility(View.VISIBLE);
            }
        }
        return;

    }

Java Solutions

Solution 1 - Java

> SetOnClickListener (Android.View.view.OnClickListener) in View cannot > be applied to (com.helloandroidstudio.MainActivity)

This means in other words (due to your current scenario) that your MainActivity need to implement OnClickListener:

public class Main extends ActionBarActivity implements View.OnClickListener {
   // do your stuff
}

This:

buttonname.setOnClickListener(this);

means that you want to assign listener for your Button "on this instance" -> this instance represents OnClickListener and for this reason your class have to implement that interface.

It's similar with anonymous listener class (that you can also use):

buttonname.setOnClickListener(new View.OnClickListener() {
   
   @Override
   public void onClick(View view) {

   }
});

Solution 2 - Java

Button button= (Button)findViewById(R.id.buttonId);
button.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View view) {
    // click handling code
   }
});

Solution 3 - Java

package com.mani.smsdetect;

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

public class MainActivity extends Activity implements View.OnClickListener {

    //Declaration Button
    Button btnClickMe;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        //Intialization Button

        btnClickMe = (Button) findViewById(R.id.btnClickMe);

        btnClickMe.setOnClickListener(MainActivity.this);
        //Here MainActivity.this is a Current Class Reference (context)
    }

    @Override
    public void onClick(View v) {
        
        //Your Logic
    }
}

Solution 4 - Java

package com.mani.helloworldapplication;

import android.app.Activity;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity implements View.OnClickListener {
    //Declaration
    TextView tvName;
    Button btnShow;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        //Empty Window
        super.onCreate(savedInstanceState);
        //Load XML File
        setContentView(R.layout.activity_main);

        //Intilization
        tvName = (TextView) findViewById(R.id.tvName);
        btnShow = (Button) findViewById(R.id.btnShow);

        btnShow.setOnClickListener(this);

    }

    @Override
    public void onClick(View v)
    {
        String name = tvName.getText().toString();
        Toast.makeText(MainActivity.this,name,Toast.LENGTH_SHORT).show();
    }
}

Solution 5 - Java

When you define an OnClickListener (or any listener) this way

btnClick.setOnClickListener(this);

you need to implement the OnClickListener in your Activity.

public class MainActivity extends ActionBarActivity implements OnClickListener{

Solution 6 - Java

public class MainActivity extends AppCompatActivity implements View.OnClickListener

Whenever you use (this) on click events, your main activity has to implement ocClickListener. Android Studio does it for you, press alt+enter on the 'this' word.

Solution 7 - Java

Start your OnClickListener, but when you get to the first set up parenthesis, type new, then View, and press enter. Should look like this when you're done:

Button btn1 = (Button)findViewById(R.id.button1);

btn1.setOnClickListener(new View.OnClickListener() {            
    @Override
    public void onClick(View v) {
//your stuff here.
    }
});

Solution 8 - Java

You can simply set onClickListener on a Button or anything using Lambda Expression which looks like

private Button buttonname;
buttonname = (Button)findViewById(R.id.buttonnameinandroid);

buttonname.setOnClickListener(v ->
    {
       //Your Listener Code Here
    });

Solution 9 - Java

> //as I understand it, the "this" denotes the current view(focus) in the android program

No, "this" will only work if your MainActivity referenced by this implements the View.OnClickListener, which is the parameter type for the setOnClickListener() method. It means that you should implement View.OnClickListener in MainActivity.

Solution 10 - Java

public class MainActivity extends Activity {

    Button button;

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

	    button = (Button) findViewById(R.id.submitButton);
	    button.setOnClickListener(new MyClass());
	
    }

    public class MyClass implements View.OnClickListener {

	    @Override
	    public void onClick(View v) {
		
	    }
	
    }
}

Solution 11 - Java

in Activity java class you would need a method first to find the view of the button as :

btnSum =(Button)findViewById(R.id.button);

after this set on click listener

btnSum.setOnClickListener(new View.OnClickListener() {

and override onClick method for your functionality .I have found a fully working example here : http://javainhouse.blogspot.in/2016/01/button-example-android-studio.html

Solution 12 - Java

Your Activity must implement View.OnClickListener, like this:

public class MainActivity extends 
Activity implements View.OnClickListener{
// YOUR CODE
}

And inside MainActivity override the method onClick(), like this:

@override
public void onClick (View view){
//here YOUR Action response to Click Button 
}

Solution 13 - Java

You need to do nothing but, just type new View.OnClickListener() in your btnClick.setOnClickListener(). I mean you have to type btnClick.setOnClickListener(new View.onClickListener the bracket will remain open, just hit enter then a method will be created like this,

btnClick.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

        }
    });

It's just mean that you are creating a new view of OnClickListener and passing a view as it's a parameter. Now you can do whatever u were supposed to do, in that onClick(View v) method.

Solution 14 - Java

Different ways to handle button event

Button btn1 = (Button)findViewById(R.id.button1);
btn1.setOnClickListener(new View.OnClickListener() {			
		@Override
		public void onClick(View v) {
			// TODO Auto-generated method stub
			Toast.makeText(context, "Button 1", 
     Toast.LENGTH_LONG).show();
		}
	});

[Check this article for more details about button event handlers]

Solution 15 - Java

public class EditProfile extends AppCompatActivity {

    Button searchBtn;
    EditText userName_editText;
    EditText password_editText;
    EditText dob_editText;
    RadioGroup genderRadioGroup;
    RadioButton genderRadioBtn;
    Button editBtn;
    Button deleteBtn;
    Intent intent;
    DBHandler dbHandler;

    public static final String USERID_EDITPROFILE = "userID";

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

        searchBtn = (Button)findViewById(R.id.editprof_searchbtn);
        userName_editText = (EditText)findViewById(R.id.editprof_userName);
        password_editText = (EditText)findViewById(R.id.editprof_password);
        dob_editText = (EditText)findViewById(R.id.editprof_dob);
        genderRadioGroup = (RadioGroup)findViewById(R.id.editprof_radiogroup);
        editBtn = (Button)findViewById(R.id.editprof_editbtn);
        deleteBtn = (Button)findViewById(R.id.editprof_deletebtn);
        intent = getIntent();


        dbHandler = new DBHandler(EditProfile.this);

        setUserDetails();

        deleteBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String username = userName_editText.getText().toString();

                if(username == null){
                    Toast.makeText(EditProfile.this,"Please enter username to delete your profile",Toast.LENGTH_SHORT).show();
                }
                else{
                    UserProfile.Users users = dbHandler.readAllInfor(username);

                    if(users == null){
                        Toast.makeText(EditProfile.this,"No profile found from this username, please enter valid username",Toast.LENGTH_SHORT).show();
                    }
                    else{
                        dbHandler.deleteInfo(username);
                        Intent redirectintent_home = new Intent("com.modelpaper.mad.it17121002.Home");
                        startActivity(redirectintent_home);
                    }
                }
            }
        });

        editBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                String userID_String = intent.getStringExtra(Home.USERID);
                if(userID_String == null){
                    Toast.makeText(EditProfile.this,"Error!!",Toast.LENGTH_SHORT).show();
                    Intent redirectintent_home =  new Intent(getApplicationContext(),Home.class);
                    startActivity(redirectintent_home);
                }
                int userID = Integer.parseInt(userID_String);

                String username = userName_editText.getText().toString();
                String password = password_editText.getText().toString();
                String dob = dob_editText.getText().toString();
                int selectedGender = genderRadioGroup.getCheckedRadioButtonId();
                genderRadioBtn = (RadioButton)findViewById(selectedGender);
                String gender = genderRadioBtn.getText().toString();

                UserProfile.Users users = UserProfile.getProfile().getUser();
                users.setUsername(username);
                users.setPassword(password);
                users.setDob(dob);
                users.setGender(gender);
                users.setId(userID);

                dbHandler.updateInfor(users);
                Toast.makeText(EditProfile.this,"Updated Successfully",Toast.LENGTH_SHORT).show();
                Intent redirectintent_home = new Intent(getApplicationContext(),Home.class);
                startActivity(redirectintent_home);
            }
        });

        searchBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               String username = userName_editText.getText().toString();
               if (username == null){
                   Toast.makeText(EditProfile.this,"Please enter a username",Toast.LENGTH_SHORT).show();
               }
               else{
                   UserProfile.Users users_search = dbHandler.readAllInfor(username);


                   if(users_search == null){
                       Toast.makeText(EditProfile.this,"Please enter a valid username",Toast.LENGTH_SHORT).show();
                   }
                   else{
                       userName_editText.setText(users_search.getUsername());
                       password_editText.setText(users_search.getPassword());
                       dob_editText.setText(users_search.getDob());
                       int id = users_search.getId();
                       Intent redirectintent = new Intent("com.modelpaper.mad.it17121002.EditProfile");
                       redirectintent.putExtra(USERID_EDITPROFILE,Integer.toString(id));
                       startActivity(redirectintent);
                   }
               }
            }
        });


    }

    public void setUserDetails(){

        String userID_String = intent.getStringExtra(Home.USERID);
        if(userID_String == null){
            Toast.makeText(EditProfile.this,"Error!!",Toast.LENGTH_SHORT).show();
            Intent redirectintent_home = new Intent("com.modelpaper.mad.it17121002.Home");
            startActivity(redirectintent_home);
        }
        int userID = Integer.parseInt(userID_String);
        UserProfile.Users users = dbHandler.readAllInfor(userID);
        userName_editText.setText(users.getUsername());
        password_editText.setText(users.getPassword());
        dob_editText.setText(users.getDob());
    }
}
Categories
Recommended Java Solutions
Recommended Android Solutions
Recommended Button Solutions
Recommended View Solutions
Recommended Android Studio Solutions

Previous Solution:

How to set default text for a Tkinter Entry widget

PythonPython 3.xPython 2.7User InterfaceTkinter

Next Solution:

user vs sudo vs sudo_user in ansible playbooks

SudoAnsible

Attributions

All content for this solution is sourced from the original question on Stackoverflow.

The content on this page is licensed under the Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license.

Content TypeOriginal AuthorOriginal Content on Stackoverflow
Questionuser2699451View Question on Stackoverflow
Solution 1 - JavaSimon DorociakView Answer on Stackoverflow
Solution 2 - JavaMohamed ZidanView Answer on Stackoverflow
Solution 3 - JavaManikanta ReddyView Answer on Stackoverflow
Solution 4 - JavaManikanta VeeramView Answer on Stackoverflow
Solution 5 - JavacodeMagicView Answer on Stackoverflow
Solution 6 - JavaGagandeepView Answer on Stackoverflow
Solution 7 - JavaCarter RayView Answer on Stackoverflow
Solution 8 - JavaViknesh TPKView Answer on Stackoverflow
Solution 9 - JavaEgorView Answer on Stackoverflow
Solution 10 - JavaMaxEchoView Answer on Stackoverflow
Solution 11 - JavaGaganView Answer on Stackoverflow
Solution 12 - JavaMukhtaar A. AzizView Answer on Stackoverflow
Solution 13 - JavaAbir HossainView Answer on Stackoverflow
Solution 14 - Javauser7925882View Answer on Stackoverflow
Solution 15 - JavaKugaruban NiroyanView Answer on Stackoverflow