How to position button relative to the bottom of the screen?-CodePudding

I'm trying to position my button 50dp above the bottom of the screen. I know how to do this if I'm positioning it relative to the top of the screen with layout_marginTop but using layout_marginBottom doesn't seem to be working, here's my code:

<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android">

    <Button
        android:id="@ id/btn1"
        android:layout_width="296dp"
        android:layout_height="67dp"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="50dp"
        android:text="Button 1" />
    
</RelativeLayout>

This is what it's showing:

And this is what I want it to show:

It feels like a dumb question, but does anyone know how to position a button relative to the bottom of the screen?

CodePudding user response：

Only add

android:layout_alignParentBottom="true"

in RelativeLayout.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
     >

    <Button
        android:id="@ id/btn1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="10dp"
        android:gravity="center"
     android:layout_alignParentBottom="true"
        android:text="Button 1" />

</RelativeLayout>

But my Suggestion is use ConstraintLayout behalf of RelativeLayout

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_height="match_parent"
    android:layout_width="match_parent">

    <Button
        android:id="@ id/btn1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="10dp"
        android:text="Button 1"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

CodePudding user response：

The way margin works, is by adding a value of X dp around the element you're setting it for. This means, by setting android:layout_marginBottom to 50dp, you're only adding 50dp of an invisible border around your button. what you need instead, is the android:layout_gravity="bottom" attribute. this aligns the element to the bottom, and you can work with android:layout_marginBottom to push the button a little higher afterwards

CodePudding user response：

Align it to bottom by setting layout_alignParentBottom to true

<Button
            android:id="@ id/btn1"
            android:layout_width="296dp"
            android:layout_height="67dp"
            android:layout_centerHorizontal="true"
            android:layout_alignParentBottom="true"
            android:text="Button 1" />

CodePudding user response：

Add android:layout_alignParentBottom="true" to button

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:gravity="bottom">

    <Button
        android:id="@ id/btn1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"            
        android:layout_marginBottom="50dp"
        android:gravity="center"
        android:text="Button 1" />

</RelativeLayout>