Cannot change the colour of the button of my android application in Android studio-CodePudding

I'm new to android studio. I started to create a mobile application. I need to add a white color button to my mobile application. I just drag and drop a button and it shows as blue color in the Android studio design as well as in my phone. After I created a button.xml to change the color of the button. But still not fixed that problem.

My phone is : Samsung M21
Android studio version: 2020.3.1 Patch 3

I will add my code of the button and screenshots of the android design as well as in my phone.

This is the problem I have.

This screenshot is in the Android Design.

This screenshot is on my mobile phone.

code of the button (activity_to_do.xml)

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".todo.ToDo">

    <Button
        android:id="@ id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        android:background="@drawable/button"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

button.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">
    <corners android:radius="50px"/>
    <solid android:color="@color/white"/>
</shape>

can anyone help me? I need to change the color of the button to white.

CodePudding user response：

This problem can be solved by changing background tint opacity (Alpha in ARGB) to 0%. However, as text color and background color are same and white, you won't see text. So below is the updated activity_to_do.xml with black as font color.

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 

xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".todo.ToDo">

<Button
    android:id="@ id/button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/button"
    android:text="Button"
    android:textColor="#000000"
    app:backgroundTint="#00FFFFFF"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

You can also use GUI for changing background tint.

Click on your button.
On the attributes, search for "tint" in search bar.
Select background tint and set value to "#00FFFFFF"