I typically use a DataGridTableStyle in order to format DG display, handle
null values, etc. You can set ReadOnly = true ,as illustrated below, to
disable editing at the column level:
// Add au_lname style
DataGridColumnStyle dgcLastName = new DataGridTextBoxColumn();
dgcLastName.MappingName = "au_lname";
dgcLastName.HeaderText = "LastName";
dgcLastName.ReadOnly = true;
ts1.GridColumnStyles.Add(dgcLastName);