Missing buttons on AlertDialog | Android 7.0 (Nexus 5x)

Question

I am trying to create an AlertDialog but the buttons are not showing. Only seeing this issue in Android 7.0:

final AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("This app needs location access");
builder.setMessage("Please grant location access so this app can detect beacons.");
builder.setPositiveButton(android.R.string.ok, null);
builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
    @Override
    @TargetApi(Build.VERSION_CODES.M)
    public void onDismiss(final DialogInterface dialog) {
        requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION}, PERMISSION_REQUEST_COARSE_LOCATION);
    }
});
builder.show();

Answer 1

Indeed it seems that AlertDialog theme needs to be defined. An alternative approach to above would be to define AlertDialog theme in Application theme:

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- ... other AppTheme items ... -->
    <item name="android:alertDialogTheme">@style/AlertDialogTheme</item>
</style>

<style name="AlertDialogTheme" parent="Theme.AppCompat.Light.Dialog.Alert">
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

Then it is enough create AlertDialog.Builder only with Context parameter.

Note: The above seems to work only for android.app.AlertDialog.Builder and is not working for AppCompat builder (android.support.v7.app.AlertDialog.Builder, at least as of version 25.0.1). In case of AppCompat builder, I had to pass theme ID as second parameter to Builder constructor to have buttons visible.

Answer 2

So it turns out on Android 7.0 you have to provide a theme. At least, that's what I had to do.

    <style name="AlertDialogTheme" parent="Theme.AppCompat.Light.Dialog.Alert">
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="borderlessButtonStyle">@style/Widget.AppCompat.Button.Borderless.Colored</item>
    </style>


    final AlertDialog.Builder alertDialog = new AlertDialog.Builder(getActivity(), R.style.AlertDialogTheme);