How to include a TextView in an Android App:
Step 1: First of all, create a new Android app, or take an existing app to edit it. In both the case, there must be an XML layout activity file and a Java class file linked to this activity.
Step 2: Open the Activity file and include a TextView in this file. The code for the TextView will be:
<TextView
android:id="@+id/textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Welcome To"
android:textSize="26sp"
android:textStyle="bold"
android:textColor="@color/colorPrimary"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
Step 3: Now in the Java file, link this layout file with the below code:
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
where activity_main is the name of the layout file to be attached.
Step 4: In the Java file, we will try to change the Text displayed on the TextView upon touching along with a Toast message.
Step 5: The complete code of the layout file and the Java file is given below.
Below is the implementation of the above approach:
package com.project.textview;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
// Creating the instance of the TextView created
private TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// Linking the activity file to this Java file
setContentView(R.layout.activity_main);
// Get the TextView with the id
// mentioned in the layout file
textView = (TextView)findViewById(R.id.textview);
// Try to change the text of the Textview upon touch
// and also display a Toast message
textView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
{
// Changing text
textView.setText("w3wiki");
// Displaying Toast message
Toast
.makeText(MainActivity.this,
"Welcome to w3wiki",
Toast.LENGTH_SHORT)
.show();
}
});
}
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
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"
tools:context=".MainActivity"
android:gravity="center">
<TextView
android:id="@+id/textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Welcome To"
android:textSize="26sp"
android:textStyle="bold"
android:textColor="@color/colorPrimary"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</RelativeLayout>
Output:
TextView widget in Android using Java with Examples
Widget refers to the elements of the UI (User Interface) that help the user interact with the Android App. TextView is one of many such widgets which can be used to improve the UI of the app. TextView refers to the widget which displays some text on the screen based on the layout, size, colour, etc set for that particular TextView. It optionally allows us to modify or edit itself as well.
Class Syntax:
public class TextView
extends View
implements ViewTreeObserver.OnPreDrawListener
Class Hierarchy:
java.lang.Object
↳ android.view.View
↳ android.widget.TextView
Syntax:
<SomeLayout>
.
.
<TextView>
android:SomeAttribute1 = "Value of attribute1"
android:SomeAttribute2 = "Value of attribute2"
.
.
android:SomeAttributeN = "Value of attributeN"
</TextView>
.
.
</SomeLayout>
Here the layout can be any layout like Relative, Linear, etc (Refer this article to learn more about layouts). And the attributes can be many among the table given below in this article.
Example:
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/text_view_id"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="w3wiki" />
</LinearLayout>