Android & lt; uses nested layout to implement the calculator interface from scratch. 17. & gt;, android nesting

Learning android from scratch <using nested layout to implement the calculator interface. 17 ..>, android nesting

The so-called nested layout is to nest multiple layout files in a file.

<span style="font-size:18px;">  <LinearLayout        android:layout_width="match_parent"        android:layout_height="fill_parent"        android:orientation="vertical" ><FrameLayout android:layout_width="match_parent"        android:layout_height="fill_parent"        android:orientation="vertical" >………………</FrameLayout ></LinearLayout></span>

Next we will use the nested layout to implement the UI effect of a simple calculator.

The following figure shows the basic concept.

Use the Xml layout file to set the calculator Effect

<span style="font-size:18px;"><?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:orientation="vertical" >    <LinearLayout        android:layout_width="match_parent"        android:layout_height="fill_parent"        android:layout_weight="3"        android:orientation="vertical" >        <TextView            android:id="@+id/text2"            android:layout_width="match_parent"            android:layout_height="fill_parent"            android:layout_marginTop="0dp"            android:layout_weight="1"            android:padding="0dp" />        <TextView            android:id="@+id/text1"            android:layout_width="match_parent"            android:layout_height="fill_parent"            android:layout_marginTop="0dp"            android:layout_weight="2"            android:padding="0dp" />    </LinearLayout>    <TableLayout        android:layout_width="match_parent"        android:layout_height="fill_parent"        android:layout_weight="1"        android:orientation="vertical" >        <TableRow            android:layout_width="match_parent"            android:layout_height="fill_parent"            android:layout_weight="0.2" >            <Button                android:id="@+id/left_bracket_button"                android:layout_height="fill_parent"                android:layout_marginBottom="1dp"                android:layout_marginLeft="1dp"                android:layout_weight="0.25"                android:background="#333333"                android:text="（"                android:textColor="@android:color/white"                android:textSize="25sp" />            <Button                android:id="@+id/right_bracket_button"                android:layout_height="fill_parent"                android:layout_marginBottom="1dp"                android:layout_marginLeft="1dp"                android:layout_weight="0.25"                android:background="#333333"                android:text="）"                android:textColor="@android:color/white"                android:textSize="25sp" />            <Button                android:id="@+id/divisor_button"                android:layout_height="fill_parent"                android:layout_marginBottom="1dp"                android:layout_marginLeft="1dp"                android:layout_weight="0.25"                android:background="#333333"                android:text="÷"                android:textColor="@android:color/white"                android:textSize="25sp" />            <Button                android:id="@+id/backspace_button"                android:layout_height="fill_parent"                android:layout_marginBottom="1dp"                android:layout_marginLeft="1dp"                android:layout_weight="0.25"                android:background="#ffa500"                android:text="C"                android:textSize="25sp" />        </TableRow>        <TableRow            android:layout_width="match_parent"            android:layout_height="fill_parent"            android:layout_weight="0.2" >              <Button                android:id="@+id/seven_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="25sp"                android:background="@android:color/darker_gray"                android:text="7" />            <Button                android:id="@+id/eight_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="25sp"                android:background="@android:color/darker_gray"                android:text="8" />            <Button                android:id="@+id/nine_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="25sp"                android:background="@android:color/darker_gray"                android:text="9" />            <Button                android:id="@+id/product_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"                android:background="#333333"                android:textSize="25sp"    android:textColor="@android:color/white"                android:text="×" />        </TableRow>        <TableRow            android:layout_width="match_parent"            android:layout_height="fill_parent"            android:layout_weight="0.2" >            <Button                android:id="@+id/four_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="25sp"                android:background="@android:color/darker_gray"                android:text="4" />            <Button                android:id="@+id/five_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="25sp"                android:background="@android:color/darker_gray"                android:text="5" />            <Button                android:id="@+id/six_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="25sp"                android:background="@android:color/darker_gray"                android:text="6" />            <Button                android:id="@+id/minus_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"                android:background="#333333"                android:textSize="25sp"    android:textColor="@android:color/white"                android:text="-" />        </TableRow>        <TableRow            android:layout_width="match_parent"            android:layout_height="fill_parent"            android:layout_weight="0.2" >             <Button                android:id="@+id/one_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="25sp"                android:background="@android:color/darker_gray"                android:text="1" />            <Button                android:id="@+id/two_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="25sp"                android:background="@android:color/darker_gray"                android:text="2" />            <Button                android:id="@+id/three_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="25sp"                android:background="@android:color/darker_gray"                android:text="3" />            <Button                android:id="@+id/plus_button"                android:layout_height="fill_parent"                android:layout_width="fill_parent"                android:layout_weight="0.25"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"                android:background="#333333"                android:textSize="25sp"    android:textColor="@android:color/white"                android:text="+" />        </TableRow>        <TableRow            android:layout_width="match_parent"            android:layout_height="fill_parent"            android:layout_weight="0.2" >            <Button                android:id="@+id/point_button"                android:layout_height="fill_parent"                android:layout_width="wrap_content"                android:layout_weight="0.5"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="40sp"                android:background="@android:color/darker_gray"                android:text="." />            <Button                android:id="@+id/zero_button"                android:layout_height="fill_parent"                android:layout_width="wrap_content"                android:layout_weight="0.5"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="25sp"                android:background="@android:color/darker_gray"                android:text="0" />                        <Button                android:id="@+id/equal_button"                android:layout_height="fill_parent"                android:layout_width="wrap_content"                android:layout_weight="3.1"                android:layout_marginLeft="1dp"    android:layout_marginBottom="1dp"    android:textSize="25sp"                android:background="#00CC00"                android:text="=" />        </TableRow>    </TableLayout></LinearLayout></span>

The following is a simulator.

The above code is used repeatedly

<span style="font-size:18px;"> android:layout_weight=""</span>

To set a layout, you must understand the concept of weight. android: layout_weight

Next forecast:

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