The button of the rounded corner is very aesthetic to implement a flat UI, but it is not too difficult to implement it. Create the xml file shape. xml in drawable-mdpi under the res directory, as shown in: shape. xml <? Xml version = "1.0" encoding = "UTF-8"?> <Shape xmlns: android = "http://schemas.android.com/apk/res/android" android: shape = "rectangle"> <! -- Fill color --> <solid android: color = "# FFFFFF"/> <! -- Set the four corners of the button to an arc --> <! -- Android: radius arc radius --> <corners android: radius = "5dip"/> <! -- Padding: The interval between the text in the Button and the Button boundary --> <padding android: left = "10dp" android: top = "10dp" android: right = "10dp" android: bottom = "10dp"/> </shape> main. xml uses shape in android: background = "@ drawable/shape. xml resource <? Xml version = "1.0" encoding = "UTF-8"?> <LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android" android: orientation = "vertical" android: layout_width = "fill_parent" android: layout_height = "fill_parent"> <TextView android: layout_width = "fill_parent" android: layout_height = "wrap_content" android: text = "@ string/hello"/> <Button android: id = "@ + id/roundButton" android: text = "rounded corner button" android: layout_width = "wrap_content" android: layou T_height = "wrap_content" android: background = "@ drawable/shape"/> </LinearLayout> strings. xml <? Xml version = "1.0" encoding = "UTF-8"?> <Resources> <string name = "hello"> Hello World, RoundButtonDemoActivity! </String> <string name = "app_name"> RoundButtonDemo </string> </resources> RoundButtonDemoActivity. java package com. android. roundButtonDemo. activity; import android. app. activity; import android. OS. bundle; import android. view. view; import android. view. view. onClickListener; import android. widget. button; import android. widget. toast; public class RoundButtonDemoActivity extends Activity {Button roundButton; @ Override public void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. main); roundButton = (Button) findViewById (R. id. roundButton); // use the Anonymous class to register the Button event roundButton. setOnClickListener (new OnClickListener () {public void onClick (View v) {Toast. makeText (RoundButtonDemoActivity. this, "you have clicked the rounded corner button", Toast. LENGTH_LONG ). show ();}});}}: