Android ImageView และ GridView แสดงรูปภาพบน GridView (GridView Column)

package com.myapp;

import android.os.Bundle;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.Toast;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;

public class MainActivity extends Activity {
	
	String[] Cmd = {"View Full","Send Photo","Shared Photo","Delete Photo"};

    Integer[] arrImg = {
            R.drawable.pic_a,
            R.drawable.pic_b,
            R.drawable.pic_c,
            R.drawable.pic_d,
            R.drawable.pic_e,
            R.drawable.pic_f,
            R.drawable.pic_g,
            R.drawable.pic_h
    };
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        // gridView1
        final GridView gView1 = (GridView)findViewById(R.id.gridView1); 
        	
        gView1.setAdapter(new ImageAdapter(this));
        
        // OnClick
        gView1.setOnItemClickListener(new OnItemClickListener() {
			public void onItemClick(AdapterView<?> parent, View v,
				int position, long id) {
				
				// View Full Image
		    	Intent newActivity = new Intent(MainActivity.this,FullImage.class);
		    	newActivity.putExtra("imgID", position);
		    	startActivity(newActivity);
		    	
			}
		});
        
        // ContontMenu
        registerForContextMenu(gView1);
      
    }
    
    @Override
    public void onCreateContextMenu(ContextMenu menu, View v,
    		ContextMenuInfo menuInfo) {
    	AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo)menuInfo;
		menu.setHeaderIcon(android.R.drawable.btn_star_big_on);	
		menu.setHeaderTitle("Command for position [" + info.position + "]");
		String[] menuItems = Cmd; 
		for (int i = 0; i<menuItems.length; i++) {
			menu.add(Menu.NONE, i, i, menuItems[i]);
		}
    }
    
    @Override
    public boolean onContextItemSelected(MenuItem item) {
    	AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo)item.getMenuInfo();
	    int menuItemIndex = item.getItemId();
		String[] menuItems = Cmd;
		String CmdName = menuItems[menuItemIndex];
	    
 
	    // Check Event Command
        if ("View Full".equals(CmdName)) {
    		// View Full Image
        	Intent newActivity = new Intent(MainActivity.this,FullImage.class);
        	newActivity.putExtra("imgID", info.position);
        	startActivity(newActivity); 
        	
        } else if ("Shared Photo".equals(CmdName)) {
          	 Toast.makeText(MainActivity.this,"Send Photo Command ("+ getResources().getResourceName(arrImg[info.position]) +")",Toast.LENGTH_LONG).show(); 
        
        } else if ("Shared Photo".equals(CmdName)) {
       	 Toast.makeText(MainActivity.this,"Send Photo Command ("+ getResources().getResourceName(arrImg[info.position]) +")",Toast.LENGTH_LONG).show(); 
       
        } else if ("Delete Photo".equals(CmdName)) {
          	 Toast.makeText(MainActivity.this,"Delete Command ("+ getResources().getResourceName(arrImg[info.position]) +")",Toast.LENGTH_LONG).show(); 
        }
        
    	return true;
    }
    

    
    public class ImageAdapter extends BaseAdapter 
    {
        private Context context;
        
        public ImageAdapter(Context c) 
        {
        	// TODO Auto-generated method stub
            context = c;
        }
 
        public int getCount() {
        	// TODO Auto-generated method stub
            return arrImg.length;
        }
 
        public Object getItem(int position) {
        	// TODO Auto-generated method stub
            return position;
        }
 
        public long getItemId(int position) {
        	// TODO Auto-generated method stub
            return position;
        }
 
		public View getView(int position, View convertView, ViewGroup parent) {
			// TODO Auto-generated method stub
            ImageView imageView;
            //imageView
            if (convertView == null) {
                imageView = new ImageView(context);
                imageView.setLayoutParams(new GridView.LayoutParams(110, 110));
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                imageView.setPadding(2, 2, 2, 2);
            } else {
                imageView = (ImageView) convertView;
            }
            imageView.setImageResource(arrImg[position]);
            return imageView;
		}
    } 
    
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

}

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

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:text="Back" />

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/button1"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="14dp" />

</RelativeLayout>