kotlin hw question

1. how to inherit the parent's width and height from the parent layout to chlid button?

there are a lot of buttons inside of the linear layout, and i want to fit the button size to layout

<LinearLayout
    android:layout_width="400dp"
    android:layout_height="60dp"
    android:orientation="horizontal"
    tools:layout_editor_absoluteX="1dp"
    tools:layout_editor_absoluteY="365dp">

    <Button
        android:id="@+id/button17"
        
        android:layout_width="330dp"
        android:layout_height="38dp"
        android:text="calculate" />
</LinearLayout>

 

 

2. how to align the items inside of linear layout

android : align?

want to align the buttons at the. center with same space.

Q3. how to designate the ratio of each button?

ex. number 0 button should be two times of other numbers

 

 

A3. by using the weight

https://m.blog.naver.com/impressives2/221491420473

 

 

Q4. margin?

android:layout_margin="2dp"

Q5. function : how to save the input data

if the button of numbers are clicked, we should save the data until the calculating button is clicked. Thus, i thought it is impossible to embed the calculator without using stack. *linked list or array form

 

 

A5. use  onclickEventListner or 

do not recommended to use onclick

1) define method in mainActivity class

(1) use toast to show the pop up message

Toast.makeText(this, "Button is clicked", Toast.LENGTH_LONG).show()

2) use it on xml file with OnClickEventListner