Clickイベントが発生しない。

ListViewA.java

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.AdapterView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;

public class ListViewA extends Activity implements OnItemClickListener {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        ListView lv= (ListView)findViewById(R.id.listview);

        // create the grid item mapping
        String[] from = new String[] {"rowid", "col_1", "col_2", "col_3"};
        int[] to = new int[] { R.id.item1, R.id.item2, R.id.item3, R.id.item4 };

        // prepare the list of all records
        List<HashMap<String, String>> fillMaps = new ArrayList<HashMap<String, String>>();
        for(int i = 0; i < 10; i++){
        	HashMap<String, String> map = new HashMap<String, String>();
        	map.put("rowid", "" + i);
        	map.put("col_1", "col_1_item_" + i);
        	map.put("col_2", "col_2_item_" + i);
        	map.put("col_3", "col_3_item_" + i);
        	fillMaps.add(map);
        }

        // fill in the grid_item layout
        SimpleAdapter adapter = new SimpleAdapter(this, fillMaps, R.layout.grid_item, from, to);
        lv.setAdapter(adapter);
    }

	@Override
	public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
		Log.d("onItemClick", "position: " + String.valueOf(position));
		Toast.makeText(this, position, Toast.LENGTH_SHORT).show();
	}
}

lv.setOnItemClickListener(this);　が抜けているから…。