I wish to display an image in a gridview.
I have a database with 4 columns - id, author, comment, filename (which holds the img path)
http://postimg.org/image/4l
in your design view click on smart tag of your gridview and select 'Edit Columns...' then in the opened window create an ImageField and in it's properties on right side of window, under 'Data' pane set the property 'DataImageUrlField' to the field that contains your urls that in this case is 'FileName'. it should works.