Are you looking to get the first line directly from the TextBox or from the database? If it's the former, the Lines property of the TextBox returns the lines of text as a String array, so you can simply get the first element. If it's the latter then you can use String.Split to split the text on line breaks to get a String array.
Note that, in a TextBox, line breaks consist of a carriage return and a line feed. Use Environment.NewLine to represent the line break when calling String.Split, which means that you MUST use an overload that supports Strings rather than Chars to split on.
Ok I understand. But in my case the datagridview is bound to either a view or a result set returned by a select query. So the splitting method in .Net will be a little cumbersome. I wanted something to do the same thing on the database side, get the final result set and bind the grid with it.