Set background and alpha of EditText

Examples of Setting background and alpha of EditText:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:layout_margin="20dp"
    android:orientation="vertical"
    tools:context="com.blogspot.android_er.androidedittextchanged.MainActivity">

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <ImageView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:src="@android:mipmap/sym_def_app_icon"/>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">
            <TextView
                android:id="@+id/title"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center_horizontal"
                android:layout_marginTop="10dp"
                android:layout_marginBottom="10dp"
                android:autoLink="web"
                android:text="http://android-er.blogspot.com/"
                android:textStyle="bold"/>
            <EditText
                android:id="@+id/edittext1"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:textSize="28dp"
                android:text="normal EditText"/>
            <EditText
                android:id="@+id/edittext2"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="EditText with background #50FFFFFF"
                android:textSize="28dp"
                android:background="#50FFFFFF"/>
            <EditText
                android:id="@+id/edittext3"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="EditText with background #FFFFFF"
                android:textSize="28dp"
                android:background="#FFFFFF"/>
            <EditText
                android:id="@+id/edittext4"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="EditText with background #FFFFFF and alpha=0.5"
                android:textSize="28dp"
                android:background="#FFFFFF"
                android:alpha="0.5"/>
        </LinearLayout>
    </FrameLayout>
</LinearLayout>