getSupportFragmentManager无法在DialogFragment上编译

我怎么能这样说:

public class TagsDialog extends DialogFragment
{
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState)
    {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        LayoutInflater inflater = getActivity().getLayoutInflater();
        builder.setView(inflater.inflate(R.layout.tags_dialog, null));
        builder.setMessage("This is a message").setTitle("TAGS");
        return builder.create();
    }
}

从我的Fragment内心来看ViewPager:

    public class MyFragment extends Fragment
    {
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
        {

    ...

            ImageView btnTags = (ImageView)view.findViewById(R.id.btnTags);
            btnTags.setOnClickListener(new View.OnClickListener()
            {
                @Override
                public void onClick(View view)
                {

                    DialogFragment dlg = new TagsDialog();
                    //this line doesn't compile
                    dlg.show(getSupportFragmentManager(), "tags");

                }
            });
}
}

我已经尝试了很长时间才能使这个工作,但getSupportFragmentManager从未解决......任何想法？

编辑:

我觉得这都是由支持FragmentManager和android.app.FragmentManager引起的,但我不知道如何解决这个问题,因为我正在使用支持库中的ViewPager ...

getSupportFragmentManager /以及所有相关的getFragManager方法(如父级和子级)总是从支持lib返回Manager,而show方法需要核心方法.

进口是:

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;

FragmentManager fm = getActivity().getSupportFragmentManager(); // returns from support lib
DialogFragment dlg = new TagsDialog();
dlg.show(fm, "tags"); // wants core...

如果我只是使用核心,那么getSupportFragmentManager()就不存在getActivity()......