setting background to Button has no effect

after i fix my issue here #1649 and changing themr, my <Button> can not change his background

when i change Theme of design tool to AppCompat i can see my new backgound

after search i found that i should change <Button> into <android.widget.Button>, why we need this

[fAntel]

@gabrielemariotti thank you very much 😃

[gabrielemariotti]

@fAntel It is a different issue.

You can check in the Layout Inspector:

In your case since you are using a Bridge Theme, you are working with an AppCompatButton.

You can use:

<com.google.android.material.button.MaterialButton
    style="@style/MainButton"
    android:id="@+id/button"
    android:layout_width="match_parrent"
    android:layout_height="wrap_content"
    android:layout_marginEnd="16dp"
    android:layout_marginStart="16dp"
    android:text="test"/>

or

    <style name="AppThemeBridge" parent="Theme.MaterialComponents.Light.NoActionBar.Bridge">
        <item name="viewInflaterClass">com.google.android.material.theme.MaterialComponentsViewInflater</item>
    </style>

otherwise use the AppCompatButton and the android:background attribute.