Android - How to create FAB programmatically?

问题:

I have an app with full of custom views. When I try to create a FAB programmatically, it throws an error

Caused by: java.lang.IllegalArgumentException: You need to use a Theme.AppCompat theme (or descendant) with the design library.

Here is my code.

private FloatingActionButton getFAB() {
    FloatingActionButton fab = new FloatingActionButton(getContext());
    fab.setBackgroundDrawable(ContextCompat.getDrawable(getContext(), R.drawable.ic_add_white_24dp));
    return fab;
}

This is my app theme.

    <!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
</style>

Please help me.

回答1:

Fixed by using theme wrapper. But still I'm surprised about using ContextThemeWrapper

private FloatingActionButton getFAB() {
    Context context = new android.support.v7.internal.view.ContextThemeWrapper(getContext(), R.style.AppTheme);
    FloatingActionButton fab = new FloatingActionButton(context);
    return fab;
}