Button in Android

In this tutorial, we would learn about Button in Android. The button is one of the basic widgets which we normally use in each Android app. For example, in the last tutorial, we learned about EditText and in the example of EditText, we added a button in the Signup form. So same like that we can use the button for a different purpose in our Android App. We can use Button in Login form Button in the Signup form. In this tutorial, we will learn how to add button widget in our XML Layout file and how to write working of that particular button in our Java file. Firstly we would start with our XML Layout file.

XML Code:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:padding="16dp"
    android:orientation="vertical"
    tools:context=".ButtonExample">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Enter Your Name"
        android:inputType="text"
        android:id="@+id/editText"
        android:layout_marginBottom="10dp"
        />
   
    <Button
        android:layout_width="250dp"
        android:layout_height="wrap_content"
        android:layout_marginBottom="10dp"
        android:textColor="@color/colorWhite"
        android:background="@color/colorPrimary"
        android:id="@+id/button"
        android:text="Create my Account"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="18sp"
        android:text="Text View"
        android:textColor="@color/colorPrimary"
        android:id="@+id/textView"/>

</LinearLayout>

Output of This XML layout file will look like this..

In this example you can see we added an EditText, a Button and a TextView and our purpose is to Enter a Name in EditText and to show that name in our TextView on click of our Button.

Java Code:

public class ButtonExample extends AppCompatActivity {

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

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String name=editText.getText().toString();
                textView.setText("Hello "+name);
            }
        });
    }
}

Here the output of when will press Button after Entering a name in EditText