问如何设置imageview优先于imageview？

EN

@Override
protected void onCreate(Bundle savedInstanceState) 
{   
    super.onCreate(savedInstanceState);
    setContentView(R.layout.headshotallphoto);
    dbHeadshot = new DataHelperHeadshot(this);

    DisplayMetrics displaymetrics = new DisplayMetrics();       
    getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);      
    ht = displaymetrics.heightPixels;      
    wt = displaymetrics.widthPixels;        

    GridView imagegrid = (GridView) findViewById(R.id.PhoneImageGrid);
    imagegrid.setAdapter(new ImageAdapter(getApplicationContext(),bmp));
    imagegrid.setOnItemClickListener(this); 
}

public class ImageAdapter extends BaseAdapter
{
    private Context mContext;
    private Bitmap[] mImageArray;

    public ImageAdapter(Context c, Bitmap[] imgArray) 
    {
          mContext = c;
          mImageArray = imgArray;

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

    }
    public Object getItem(int position)
    {
          return position;
    }
    public long getItemId(int position)
    {
          return position;
    }

    public View getView(int position,View convertView,ViewGroup parent)
    {
        System.gc();
        ImageView i = null ;//= new ImageView(mContext.getApplicationContext());

        if (convertView == null) 
        {               
            i = new ImageView(mContext);
            i.setLayoutParams(new GridView.LayoutParams(92,92));
            i.setScaleType(ImageView.ScaleType.CENTER_CROP);
            i.setPadding(8, 8, 8, 8); 
            i.setImageBitmap(mImageArray[position]);              
        }
         else 
             i = (ImageView) convertView;           
         return i;
    }
}

public Bitmap decodeFile(String filePath) 
{
    BitmapFactory.Options o = new BitmapFactory.Options();
    o.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(filePath, o);

    // The new size we want to scale to
    final int REQUIRED_SIZE = 100;
    final int H = 50;

    // Find the correct scale value. It should be the power of 2.
    int width_tmp = o.outWidth, height_tmp = o.outHeight;
    int scale = 1;
    while (true) {
        if (width_tmp < REQUIRED_SIZE && height_tmp < H)
            break;
        width_tmp /= 2;
        height_tmp /= 2;
        scale *= 2;
    }
    // Decode with inSampleSize
    BitmapFactory.Options o2 = new BitmapFactory.Options();
    o2.inSampleSize = scale;        
    bitmap = BitmapFactory.decodeFile(filePath, o2);
    return bitmap;
}

public void onItemClick(AdapterView<?> a, View v, int position, long id) 
{
    ImageView tickmark = new ImageView(this);
    tickmark.setBackgroundResource(R.drawable.imgredselectmark);
}