¿Cómo hacer que TextView sea desplazable en Android?

En Android, TextView es un elemento principal de la interfaz de usuario que se usa para mostrar el texto presente en forma de números, strings y párrafos. Sin embargo, para que se muestre una gran cantidad de información, el ajuste de tamaño no funciona. Entonces, en este artículo, le mostraremos cómo hacer que TextView sea desplazable en Android. Siga los pasos a continuación una vez que el IDE esté listo.

TextView se puede hacer desplazable por dos métodos:

1. Usando ScrollView: con la ayuda de ScrollView , puede hacer que una vista se pueda desplazar vertical u horizontalmente.

2. Usando el atributo ScrollBar presente en TextView

Implementación paso a paso

Paso 1: crea un nuevo proyecto en Android Studio

Para crear un nuevo proyecto en Android Project solo consulte este artículo sobre Cómo crear un nuevo proyecto en Android Studio . El código se ha proporcionado tanto en Java como en el lenguaje de programación Kotlin para Android.

Paso 2: trabajar con el archivo activity_main.xml

Vaya a la aplicación > res > diseño > actividad_principal.xml y agregue el siguiente código a ese archivo. A continuación se muestra el código para el archivo  activity_main.xml .

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">
  
    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:scrollbars="vertical"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        android:textSize="25dp" />
</androidx.constraintlayout.widget.ConstraintLayout>

Paso 3: trabajar con el archivo MainActivity

Vaya a aplicación > java > nombre del paquete de su aplicación > Archivo MainActivity (Java o Kotlin) y agréguele el siguiente código. Se agregan comentarios en el código para conocer en detalle.

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.text.method.ScrollingMovementMethod;
import android.widget.TextView;
  
public class MainActivity extends AppCompatActivity {
  
    // Declaring TextView from the Layout
    TextView textview;
  
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
  
        // initializing the TextView
        textview = findViewById(R.id.text);
  
        // Creating a string that contains the information to be displayed
        String para = "JAVA IS A TECHNOLOGY OF CHOICE FOR BUILDING APPLICATIONS" +
                " USING MANAGED CODES THAT CAN EXECUTE ON MOBILE DEVICES.\n" +
                "\n" +
                "Android is an open source software platform and Linux-based" +
                " operating system for mobile devices. The Android platform " +
                "allows developers to write managed code using Java to manage " +
                "and control the Android device. Android applications can be" +
                " developed by using the Java programming language and the " +
                "Android SDK. So, familiarity with the basics of the Java " +
                "programming language is a prerequisite for programming on" +
                " the Android platform. This article discusses where Java fits" +
                " in mobile application development and how we can use Java and" +
                " Android SDK to write applications that can work on Android devices.\n" +
                "\n" +
                "THE CHOICE OF JAVA\n" +
                "\n "+
                "What made Java be the technology of choice for mobile development for the" +
                " Android platform? The Java Programming Language emerged in the mid-1990s;" +
                " it was created by James Gosling of Sun Microsystems. Incidentally," +
                " Sun Microsystems was since bought by Oracle." +
                " Java has been widely popular the world over, " +
                "primarily because of a vast array of features it provides. " +
                "Java’s promise of “Write once and run anywhere” was one of the major" +
                " factors for the success of Java over the past few decades.\n" +
                "\n" +
                "Java even made inroads into embedded processors technology as well;" +
                " the Java Mobile Edition was built for creating applications " +
                "that can run on mobile devices. All these, added to Java’s meteoric rise," +
                " were the prime factors that attributed to the decision of adopting " +
                "Java as the primary development language for building " +
                "applications that run on Android. Java programs are secure because" +
                " they run within a sandbox environment. Programs written in Java are compiled " +
                "into intermediate code known as bytecode. This bytecode is then executed inside" +
                " the context of the Java Virtual Machine. You can learn more about Java from" +
                " this link.\n" +
                "\n" +
                "USING JAVA FOR BUILDING MOBILE APPLICATIONS\n" +
                "\n" +
                "The mobile edition of Java is called Java ME. Java ME is based on Java " +
                "SE and is supported by most smartphones and tablets. The Java Platform" +
                " Micro Edition (Java ME) provides a flexible, secure environment for" +
                " building and executing applications that are targeted at embedded and " +
                "mobile devices. The applications that are built using Java ME are portable," +
                " secure, and can take advantage of the native capabilities of the device. " +
                "Java ME addresses the constraints that are involved in building applications " +
                "that are targeted at mobile devices. In essence, Java ME addresses the " +
                "challenge of executing applications on devices " +
                "that are low on available memory, display, and power.\n" +
                "\n" +
                "There are various ways to build applications for Android devices," +
                " but the recommended approach is to leverage the" +
                " Java programming language and the Android SDK." +
                " You can explore more about the Android SDK Manager from here.";
  
        // set value to the given TextView
        textview.setText(para);
  
        // to perform the movement action
        // Moves the cursor or scrolls to the
        // top or bottom of the document
        textview.setMovementMethod(new ScrollingMovementMethod());
    }
}

import android.os.Bundle
import android.text.method.ScrollingMovementMethod
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity
  
class MainActivity : AppCompatActivity() {
  
    // Declaring TextView from the Layout
    private lateinit var textview: TextView
  
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
  
        // initializing the TextView
        textview = findViewById(R.id.text)
  
        // Creating a string that contains the information to be displayed
        val para = """JAVA IS A TECHNOLOGY OF CHOICE FOR BUILDING APPLICATIONS USING MANAGED CODES THAT CAN EXECUTE ON MOBILE DEVICES.
  
                Android is an open source software platform and Linux-based operating system for mobile devices. The Android platform allows developers 
                to write managed code using Java to manage and control the Android device. Android applications can be developed by using the Java 
                programming language and the Android SDK. So, familiarity with the basics of the Java programming language is a prerequisite for 
                programming on the Android platform. This article discusses where Java fits in mobile application development and how we can use Java 
                and Android SDK to write applications that can work on Android devices.
                  
                THE CHOICE OF JAVA
                  
                What made Java be the technology of choice for mobile development for the Android platform? The Java Programming Language emerged in the 
                mid-1990s; it was created by James Gosling of Sun Microsystems. Incidentally, Sun Microsystems was since bought by Oracle. Java has been 
                widely popular the world over, primarily because of a vast array of features it provides. Java’s promise of “Write once and run anywhere” 
                was one of the major factors for the success of Java over the past few decades.
                  
                Java even made inroads into embedded processors technology as well; the Java Mobile Edition was built for creating applications that can 
                run on mobile devices. All these, added to Java’s meteoric rise, were the prime factors that attributed to the decision of adopting Java 
                as the primary development language for building applications that run on Android. Java programs are secure because they run within a 
                sandbox environment. Programs written in Java are compiled into intermediate code known as bytecode. This bytecode is then executed inside 
                the context of the Java Virtual Machine. You can learn more about Java from this link.
                  
                USING JAVA FOR BUILDING MOBILE APPLICATIONS
                  
                The mobile edition of Java is called Java ME. Java ME is based on Java SE and is supported by most smartphones and tablets. The Java Platform 
                Micro Edition (Java ME) provides a flexible, secure environment for building and executing applications that are targeted at embedded and 
                mobile devices. The applications that are built using Java ME are portable, secure, and can take advantage of the native capabilities of the 
                device. Java ME addresses the constraints that are involved in building applications that are targeted at mobile devices. In essence, Java ME 
                addresses the challenge of executing applications on devices that are low on available memory, display, and power.
                  
                There are various ways to build applications for Android devices, but the recommended approach is to leverage the Java programming language 
                and the Android SDK. You can explore more about the Android SDK Manager from here."""
  
        // set value to the given TextView
        textview.text = para
  
        // to perform the movement action
        // Moves the cursor or scrolls to the
        // top or bottom of the document
        textview.movementMethod = ScrollingMovementMethod()
    }
}

Producción: