I've followed an example I found on your site for creating a custom gridview column.
I was able to get it to work and populate, but only by manually editing the designer document of the form in which the grid was located. My column type, however, does appear on my list of column types but after adding it, and when I try closing the grid design window I get an error. Can you tell me what I'm doing wrong? Attached a screen shot showing my columntype in the list, the column added (column1), and the error message I received. Thanks for any help you can give me.