Use java file for a xml layout file used in a dialog box

Question

I need to use a .java file to perform actions for a .xml layout. I have used this layout for a dialog box. I have linked the .java file to that layout but it doesn't seem to work at all.

This is the MainActivity

package com.example.ayush.projectfive;
import android.content.DialogInterface;
import android.content.Intent;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

Button btn;
AlertDialog.Builder alrt;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    btn = (Button) findViewById(R.id.button);

    alrt = new AlertDialog.Builder(MainActivity.this);
    alrt.setIcon(R.mipmap.ic_launcher);
    alrt.setTitle("Login");
    alrt.setCancelable(false);
    alrt.setView(R.layout.mylayout);
    alrt.setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {

        }
    });
    alrt.setNegativeButton("CANCEL", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
        }
    });

    btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            alrt.show();
            Intent i = new Intent(MainActivity.this,Second.class);
            startActivity(i);
        }
    });
}
}

This is the activity_main

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.ayush.projectfive.MainActivity">


<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="EXIT"
    android:id="@+id/button"
    android:layout_gravity="center_horizontal" />

This is the dialog box layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="LOGIN"
    android:id="@+id/textView"
    android:layout_gravity="center_horizontal" />

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="Username"
    android:layout_marginTop="20dp"
    android:id="@+id/editText" />

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="Password"
    android:layout_marginTop="15dp"
    android:inputType="textPassword"
    android:ems="10"
    android:id="@+id/editText2" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Login"
    android:layout_marginTop="20dp"
    android:id="@+id/button3" />

This is the .java file I'd like to link with.

package com.example.ayush.projectfive;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class Second extends AppCompatActivity{

EditText et, et2;
Button btn2;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.mylayout);
    et = (EditText) findViewById(R.id.editText);
    et2 = (EditText) findViewById(R.id.editText2);
    btn2 = (Button) findViewById(R.id.button3);
    btn2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String s1 = et.getText().toString();
            String s2 = et.getText().toString();
            if(s1.equals(s2)){
                Toast.makeText(Second.this, "Login Successful",      Toast.LENGTH_SHORT).show();
                Intent i = new Intent(Second.this,Third.class);
                startActivity(i);
            }
            else{

            }
        }
    });

}
}

make sure that your java file extends Dialog and implements onclicklistener, if you post the code problem will be easily solved — Urja Pawar, Jun 27 '16 at 14:42
Take a look at http://stackoverflow.com/questions/13341560/how-to-create-a-custom-dialog-box-in-android — Urja Pawar, Jun 27 '16 at 14:49
Why do you move to your activity Second with an Exit button? — Noureddine Ouertani, Jun 27 '16 at 16:18
Do you want both the exit button and the dialog box to appear in the main activity? — Noureddine Ouertani, Jun 27 '16 at 16:22
"*need to use a .java file to perform actions for a .xml layout*"... That's a large use-case of the XML & Java interoperability in Android... What exactly is your expected behavior? — OneCricketeer, Jun 27 '16 at 18:15

Noureddine Ouertani · Answer 1 · 2016-06-27T19:10:10.740

just add alrt.show(); in your MainActivity.java e.g. here:

public class MainActivity extends AppCompatActivity {

Button btn;
AlertDialog.Builder alrt;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    btn = (Button) findViewById(R.id.button);

    alrt = new AlertDialog.Builder(MainActivity.this);
    alrt.setIcon(R.mipmap.ic_launcher);
    alrt.setTitle("Login");
    alrt.setCancelable(false);
    alrt.setView(R.layout.mylayout);

    alrt.setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {

        }
    });
    alrt.setNegativeButton("CANCEL", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
        }
    });

alrt.show();

    btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i = new Intent(MainActivity.this,Second.class);
            startActivity(i);
        }
    });
}
}

What if OP intended on showing the dialog on a button click? — OneCricketeer, Jun 27 '16 at 19:07
let´s wait and see what his intention is. I already asked for a description of the expected behaviour. — Noureddine Ouertani, Jun 27 '16 at 19:09

score 0 · Answer 2 · edited Jun 20 '20 at 09:12

This is the .java file I'd like to link with [...]

public class Second extends AppCompatActivity{

Okay... That's what this code does

Intent i = new Intent(MainActivity.this,Second.class);
startActivity(i);

If you are trying to use the views that are contained within the dialog box and respond to the buttons there to login, then you need to remove the button from the activity, add alrt.show() in the onCreate instead of onClick and move the Activity start code into the dialog's onClick handlers.

It's also worth mentioning that the object is a builder, so you can do this

View dialogView = LayoutInflater.from(MainActivity.this).inflate(R.layout.mylayout, null);
final EditText editUsername = dialogView.findViewById(R.id.editText);
// TODO: Get other views from mylayout.xml

new AlertDialog.Builder(MainActivity.this)
    .setIcon(R.mipmap.ic_launcher)
    .setTitle("Login")
    .setCancelable(false)
    .setView(dialogView)
    .setPositiveButton("OK", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            String username = editUsername.getText().toString();
            // TODO: Get more variables
            // TODO: Verify credentials
            Intent i = new Intent(MainActivity.this,Second.class);
            startActivity(i);
        }
    })
    .setNegativeButton("CANCEL", null)
    .show();

And, as stated earlier, remove btn.setOnClickListener

Use java file for a xml layout file used in a dialog box

2 Answers2