ダイアログの上にListViewを表示してクリックした場所をToastで表示する

dir_list.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

MainActivity.java

package com.sakurafish.android.example.myexamplelistondialog;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity {
    final int DIALOG = 1;
    Context mContext;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mContext = getApplicationContext();
        showDialog(DIALOG);
    }

    @Override
    protected Dialog onCreateDialog(int id) {
        String[] str1 = {
                "test1", "test2", "test3", "test4", "test5", "test6", "test7", "test8"
        };
        ArrayAdapter<String> arrayAdapter1 = new
                ArrayAdapter<String>(this, R.layout.dir_list, str1);
        ListView listView1 = new ListView(this);
        listView1.setAdapter(arrayAdapter1);
        // ListViewが選択されたときの挙動
        listView1.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Toast toast = Toast.makeText(mContext, "Selected position=" + position,
                        Toast.LENGTH_SHORT);
                toast.show();
            }
        });
        AlertDialog.Builder dialog = new AlertDialog.Builder(this);
        LinearLayout layout = new LinearLayout(this);
        layout.setOrientation(LinearLayout.VERTICAL);
        layout.addView(listView1);

        dialog.setTitle("ListViewTest");
        dialog.setMessage("ListViewTest");
        dialog.setView(layout);
        dialog.setPositiveButton("はい", new
                DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int
                            whichButton) {
                        setResult(RESULT_OK);
                    }
                });
        dialog.setNegativeButton("いいえ", new
                DialogInterface.OnClickListener()
                {
                    @Override
                    public void onClick(DialogInterface dialog, int
                            whichButton) {
                        setResult(RESULT_CANCELED);
                    }
                });
        return dialog.create();
    }
}