從下拉列表中合併數據表中的數據表中的2列

Question

var id = Session["staff_id"].ToString() 

//I have datatable with 5 columns 

DataTable dt = function_return_Datatable(id); 

dropdownlist1.DataSource = dt; 

/*in DataTextField I want to merge two columns of DataTable, dt.columns [1] is First Name and dt.columns [2] is LastName*/ 

//I tried this way to merge them, but no results 
dropdownlist1.DataTextField = dt.Columns[1].ToString()+" "+dt.Columns[2].ToString(); 

dropdownlist1.DataValueField = dt.Columns[0].ToString(); 
dropdownlist1.DataBind(); 

有關如何合併這兩列的任何想法？

Answer 1

你會在你的數據表需要一個完整的名字列DataTextField可以指只有一個單場：

DataTable dt = function_return_Datatable(id); 
dt.Columns.Add("FullName", typeof(string), "FirstName + ' ' + LastName"); 

dropdownlist1.DataSource = dt; 
dropdownlist1.DataTextField = "FullName"; 
dropdownlist1.DataValueField = "ID"; 
dropdownlist1.DataBind(); 

應該這樣做

（你也可以在你的SQL添加此列查詢）