Android Button Design and selector

For first The xml file for may main layout in android activity is following

main.xml
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<?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" />
<LinearLayout android:orientation="horizontal"
android:layout_width="wrap_content" android:layout_height="wrap_content">
<Button android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="Done" android:id="@+id/donebtn"
android:padding="5dip" android:background="@drawable/button_view" />
<Button android:layout_width="wrap_content"
android:layout_height="wrap_content" android:text="back" android:id="@+id/backbtn"
android:padding="5dip" android:background="@drawable/button_view" />
</LinearLayout>
<LinearLayout android:orientation="horizontal"
android:layout_width="wrap_content" android:layout_height="wrap_content">
<Button android:text="button_selector" android:layout_width="wrap_content"
android:layout_height="wrap_content" android:background="@drawable/selector" />
</LinearLayout>
</LinearLayout>

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After declare main xml file we will make 

<?xml version="1.0" encoding="UTF-8"?>

<shape xmlns:android="http://schemas.android.com/apk/res/android"

android:shape="rectangle">

<solid android:color="#453657" />

<stroke android:width="1dp" android:height="1dp"  android:color="#FFD40F"  />

<corners android:bottomLeftRadius="8dip"

android:topRightRadius="8dip" android:topLeftRadius="8dip"

android:bottomRightRadius="8dip" />

</shape>

this xml file in drawable folder of your project .

<solid/> this tag is for background color of shape

<stroke/> this tag is used for boarder of shape

<corners/> this tag is used for make the corner round at given value.

and now for changing on button clicked changes we define again new xml file like this below.

Selector.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">

<item android:drawable="@drawable/spinner_dropdown_background_down"

android:state_pressed="true" />

 

<item android:drawable="@drawable/spinner_dropdown_background_down" 

android:state_focused="true" />

<item android:drawable="@drawable/spinner_dropdown_background_up" />

</selector>