public class MyBottomSheet extends BottomSheetDialogFragment {
    private static final String TAG = "MyBottomSheet";

    @NonNull
    @Override
    public Dialog onCreateDialog(final Bundle savedInstanceState) {
        final BottomSheetDialog dialog = (BottomSheetDialog) super.onCreateDialog(savedInstanceState);

        final View view = View.inflate(getContext(),R.layout.my_custom_view,null);

        dialog.setContentView(view);
        behavior = BottomSheetBehavior.from((View) view.getParent());

        return dialog;
    }

    public void show(final FragmentActivity fragmentActivity) {
        show(fragmentActivity.getSupportFragmentManager(),TAG);
    }
}

要像平常一样关闭对话框,请调用close().