design custom button in android

1    <?xml version="1.0" encoding="UTF-8"?>
2<shape 
3    xmlns:android="http://schemas.android.com/apk/res/android">
4    <stroke 
5        android:width="1dp" 
6        android:color="#505050"/>
7    <corners 
8        android:radius="7dp" />
9
10    <padding 
11        android:left="1dp"
12        android:right="1dp"
13        android:top="1dp"
14        android:bottom="1dp"/>
15
16    <solid android:color="#505050"/>
17
18</shape>

1android:src="@drawable/twitter"

1android:background="@drawable/button_shape"