TextView in android:-

TextView can only display result as txt type of value.as well as String .that sit.

It's also use for know and required sum info which is hidden
Ex:-
<RelativeLayout 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: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=".MainActivity" >
 <Button
        android:id="@+id/bt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Click Me" />

     <TextView
        android:id="@+id/tv"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Click on the Button to change this text" />
   
</RelativeLayout>

MainActivity:-

package com.AmitSharma.textview;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.View;

import android.widget.Button;

import android.widget.TextView;

public class MainActivity extends Activity {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

 Button button = (Button) findViewById(R.id.bt);  

button.setOnClickListener(new View.OnClickListener() {

          

           @Override

           public void onClick(View v) {

               // TODO Auto-generated method stub

              

               //Creating TextView Variable

               TextView text = (TextView) findViewById(R.id.tv);

              

               //Sets the new text to TextView (runtime click event)

               text.setText("You Have click the button");

           }

       });

  

   }

}

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u can also give on there styles of text 

ex:-

<style name="TransparentActivity" >

    <item name="android:windowBackground">@android:color/transparent</item>

    <item name="android:colorBackgroundCacheHint">@null</item>

    <item name="android:windowIsTranslucent">true</item>

    <item name="android:windowAnimationStyle">@android:style/Animation</item>

    <item name="android:windowNoTitle">true</item>

    <item name="android:windowContentOverlay">@null</item>

    <item name="android:windowFullscreen">false</item>

</style>

.............thank to u friends .............Look more again nd again ..........