i think it is issue of editmode textboxes sizes.
try this to that:-
protected void RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow && e.Row.RowState == DataControlRowState.Edit)
{
TextBox comments = (TextBox)e.Row.Cells[column_index].Controls[control_index];
comments.TextMode = TextBoxMode.MultiLine;
comments.Height = 100;
comments.Width = 400;
}
}
or in design
Set the
ItemStyle-Width and
ControlStyle-Width, and if you want wrap the text use
ItemStyle-Wrap.