title: Hello, GridView Tutorial not working
body: <p>I have followed the tutorial and can't seem to get it to work. Here's my code:</p>
  
  <p>GridView.java:</p>
  
  <pre><code>package com.example.gridview;
  
  import android.app.Activity;
  import android.os.Bundle;
  
  public class GridView 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.setAdapter(new ImageAdapter(this));
  
      gridview.setOnItemClickListener(new OnItemClickListener() {
          public void onItemClick(AdapterView&lt;?&gt; parent, View v, int position, long id) {
              Toast.makeText(HelloGridView.this, "" + position, Toast.LENGTH_SHORT).show();
          }
      });
  }
  </code></pre>
  
  <p>ImageAdapter.java</p>
  
  <pre><code>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
      };
  </code></pre>
  
  <p>main.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;GridView xmlns:android="http://schemas.android.com/apk/res/android" 
      android:id="@+id/gridview"
      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"
  </code></pre>
  
  <p>All I get are error message everywhere. What did I do wrong? I followed everything the tutorial said to do.</p>