HelloGridview Android tutorial - blank screen when run

I was doing the HelloGridview Android tutorial, Managed to fix the errors I was experiencing and got it to compile, but when I run the project all I see is a blank screen.

Is it something to do with the folder layout in my project? I created a new folder called 'drawable', separate to the drawable-hdpi, drawable-idpi and drawable-mdpi folders

Here's the xml and the two classes

<?xml version="1.0" encoding="utf-8"?>
<GridView xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/g开发者_开发知识库ridview"
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"
    android:columnWidth="90dp"
    android:numColumns="auto_fit"
    android:verticalSpacing="10dp"
    android:horizontalSpacing="10dp"
    android:stretchMode="columnWidth"
    android:gravity="center"
/>


package com.example.hellogridview;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
import android.widget.Toast;

public class HelloGridView extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        GridView gridView = (GridView) findViewById(R.id.gridview);

        gridView.setOnItemClickListener(new OnItemClickListener() {

            public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
                Toast.makeText(HelloGridView.this, "" + position, Toast.LENGTH_SHORT).show();
            }   

        });

    }
}

package com.example.hellogridview;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;

public class ImageAdapter extends BaseAdapter {
    private Context mContext;

    public ImageAdapter(Context c)
    {
        mContext = c;
    }

    public int getCount()
    {
        return mThumbIds.length;
    }

    public Object getItem(int position) {
        return null;
    }

    public long getItemId(int position) {
        return 0;
    }

    // create a new ImageView for each item referenced by the Adapter
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView;
        if (convertView == null) {  // if it's not recycled, initialize some attributes
            imageView = new ImageView(mContext);
            imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            imageView.setPadding(8, 8, 8, 8);
        } else {
            imageView = (ImageView) convertView;
        }

        imageView.setImageResource(mThumbIds[position]);
        return imageView;
    }

    // references to our images
    private Integer[] mThumbIds = {
            R.drawable.sample_2, R.drawable.sample_3,
            R.drawable.sample_4, R.drawable.sample_5,
            R.drawable.sample_6, R.drawable.sample_7,
            R.drawable.sample_0, R.drawable.sample_1,
            R.drawable.sample_2, R.drawable.sample_3,
            R.drawable.sample_4, R.drawable.sample_5,
            R.drawable.sample_6, R.drawable.sample_7,
            R.drawable.sample_0, R.drawable.sample_1,
            R.drawable.sample_2, R.drawable.sample_3,
            R.drawable.sample_4, R.drawable.sample_5,
            R.drawable.sample_6, R.drawable.sample_7
    };

}

Any help would be much appreciated, thanks.

I think you forgot this line

gridView.setAdapter(new ImageAdapter(this));

after

GridView gridView = (GridView) findViewById(R.id.gridview);

1) Ensure that the adapter is set right .

2) Ensure that the getItem and getItemId is not returning null values . The default return values of the unimplemented methods are set to null values so we tend to ignore it : So getCount() should return the length of the array ( like you have done ) , the getItem should return the value : like this : return mThumbIds[position];

Just to make sure, do you have images in your drawable folder that are the same names as those in the mThumbIds?

just to make sure do you have your drawable folder.If not,create a new one,then copy those drawings into it.I address this issue in this way.