datagrid view is not showing images

Question

while(rdr.Read())

{

DataGridViewImageColumn iconColumn = new DataGridViewImageColumn();

ImageConverter ic;

Image img;

Byte[] cbyte;

ic = new ImageConverter();

cbyte = (Byte[])(rdr["Imge"]);

img = (Image)ic.ConvertFrom(cbyte);

Bitmap a = new Bitmap(img);

iconColumn.Image = a;

iconColumn.Name = "Tree";

iconColumn.HeaderText = "Nice tree";

dataGridView1.Columns.Insert(0, iconColumn);

};