Calculator Design - Sample Project

To day we will try to design the simple calculator application. Lets start

Here is the code of Calculator

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"   android:layout_width="match_parent"   android:layout_height="match_parent"   android:background="#bf000000"   android:orientation="vertical">   <TextView       android:id="@+id/Answer"       android:layout_width="match_parent"       android:layout_height="wrap_content"       android:layout_margin="2dp"       android:layout_weight="1.5"       android:background="#fff"       android:hint="0"       android:padding="5dp"       android:textColor="#000" />   <LinearLayout       android:layout_width="match_parent"       android:layout_height="wrap_content"       android:layout_weight="1">       <Button           android:id="@+id/ac"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="AC"           android:textSize="20sp" />       <Button           android:id="@+id/neg"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="+/-"           android:textSize="20sp" />       <Button           android:id="@+id/mod"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="%"           android:textSize="20sp" />       <Button           android:id="@+id/divide"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:background="#eae66107"           android:text="/"           android:textSize="20sp" />   </LinearLayout>   <LinearLayout       android:layout_width="match_parent"       android:layout_height="wrap_content"       android:layout_weight="1">       <Button           android:id="@+id/btn7"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="7"           android:textSize="20sp" />       <Button           android:id="@+id/btn8"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="8"           android:textSize="20sp" />       <Button           android:id="@+id/btn9"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="9"           android:textSize="20sp" />       <Button           android:id="@+id/cross"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:background="#eae66107"           android:text="x"           android:textSize="20sp" />   </LinearLayout>   <LinearLayout       android:layout_width="match_parent"       android:layout_height="wrap_content"       android:layout_weight="1">       <Button           android:id="@+id/btn4"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="4"           android:textSize="20sp" />       <Button           android:id="@+id/btn5"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="5"           android:textSize="20sp" />       <Button           android:id="@+id/btn6"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="6"           android:textSize="20sp" />       <Button           android:id="@+id/minus"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:background="#eae66107"           android:text="-"           android:textSize="20sp" />   </LinearLayout>   <LinearLayout       android:layout_width="match_parent"       android:layout_height="wrap_content"       android:layout_weight="1">       <Button           android:id="@+id/btn1"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="1"           android:textSize="20sp" />       <Button           android:id="@+id/btn2"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="2"           android:textSize="20sp" />       <Button           android:id="@+id/btn3"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="3"           android:textSize="20sp" />       <Button           android:id="@+id/plus"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:background="#eae66107"           android:text="+"           android:textSize="20sp" />   </LinearLayout>   <LinearLayout       android:layout_width="match_parent"       android:layout_height="wrap_content"       android:layout_weight="1">       <Button           android:id="@+id/btn0"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="8"           android:text="0"           android:textSize="20sp" />       <Button           android:id="@+id/dot"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:text="."           android:textSize="20sp" />       <Button           android:id="@+id/equal"           android:layout_width="wrap_content"           android:layout_height="match_parent"           android:layout_margin="2dp"           android:layout_weight="1"           android:background="#eae66107"           android:text="="           android:textSize="20sp" />   </LinearLayout> </LinearLayout>