contextthemewrapper cannot be cast to activity

From what I know, if a View that is shown in a Dialog, its context (access from view.getContext()) is actually a ThemeContextWrapper instance, which is probably not an Activity. To get the activity from the Dialog, you can use getOwnerActivity(), which returns the Activity that the Dialog belongs to.

Similar case I have. May be related question> Accessing activity from custom button

I solve my case with this snippet.

private static Activity scanForActivity(Context cont) {
    if (cont == null)
        return null;
    else if (cont instanceof Activity)
        return (Activity)cont;
    else if (cont instanceof ContextWrapper)
        return scanForActivity(((ContextWrapper)cont).getBaseContext());

    return null;
}

Activity a= (Activity)(photoToLoad.imageView.getContext());

You can't assume a Context can be casted to an Activity. Hence the exception: You're attempting to cast a Context that is in fact a ContextThemeWrapper to an Activity.

You can replace

Activity a= (Activity)(photoToLoad.imageView.getContext());
a.runOnUiThread(bd);

with e.g.

photoToLoad.imageView.post(bd);

to post a Runnable to UI thread message queue, similar to Activity runOnUiThread().

Kotlin solution in addition to kikea's answer.

fun Context.scanForActivity(): AppCompatActivity? {
   return when (this) {
       is AppCompatActivity -> this
       is ContextWrapper -> baseContext.scanForActivity()
       else -> null
    }
}