Android Textbox Tutorial

Introduction of Android Textbox Control

Android provides textbox Control for user interface. Textbox control user can enter information and submit. It is like webpage textbox that can be used multiple purposes.

How to define textbox control

Android use seperate file for layout. This file stored in android res/layout directory.

syntex :

 <TextView
        android:id="@+id/txtname"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
 <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="show text" />        
 

Above syntex define textbox with following properties

• android:id a unique id provided.
• android:layout_width this property is used to define width.
• android:layout_heightthis property is used to define height.

set OnClickListener for button. We need to set it manually.

How to set OnClickListener to button

• First identify your button.

   Syntex :
   
   button = (Button) findViewById(R.id.button1);
   

• Then set event to this button control

   button.setOnClickListener(new OnClickListener() {
   
  			@Override
  			public void onClick(View arg0) {
                  write your code
  			}
   
  		});
   

• Then get textbox content and display it

   TextView txtname = (TextView) findViewById(R.id.txtname);
   String name=txtname.getText().toString()
   Toast.makeText(this,name,Toast.LENGTH_LONG).show();
   

Example

1. Make layout file(main.xml) which contains a button. If we click on button it display a message.
   
   

   <?xml version="1.0" encoding="utf-8"?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
       android:id="@+id/linearLayout1"
       android:layout_width="fill_parent"
       android:layout_height="fill_parent"
       android:orientation="vertical" >
    
    <TextView
           android:id="@+id/txtname"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"/>
    <Button
           android:id="@+id/button1"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:text="show text" />  
    
   </LinearLayout>
   

2. Then apply onclick event
   
   

   public class MyAndroidAppActivity extends Activity {
    
   	@Override
   	public void onCreate(Bundle savedInstanceState) {
   		super.onCreate(savedInstanceState);
   		setContentView(R.layout.main);
    
   		addListenerOnButton();
    
   	}
    
   	public void addListenerOnButton() {
    
   		Button button = (Button) findViewById(R.id.button1);
    
   		button.setOnClickListener(new OnClickListener() {
    
   			@Override
   			public void onClick(View arg0) {
    
                TextView txtname = (TextView) findViewById(R.id.txtname);
                String name=txtname.getText().toString()
                Toast.makeText(this,name,Toast.LENGTH_LONG).show();
   			}
    
   		});
    
   	}
    
   }
   
   

3. Output :