填充COMBOX与第一项

Question

我用下面的技术用于填充在WinForms的组合框：

var customer = (new Customer[] { new Customer { CustomerID = -1, CustomerRef = "[Please Select]" } }).Concat(
    from c in ctx.Customers 
    orderby c.CustomerRef ascending 
    select c).ToList(); 

cboCustomerRef.DataSource = customer; 
cboCustomerRef.ValueMember = "CustomerID"; 
cboCustomerRef.DisplayMember = "CustomerRef"; 

是否可以达到同样的效果，但只有选择的两个相关的列（CustomerID和CustomerRef ）而不是所有栏目。

有没有更好的方法来做到这一点？

谢谢...

Answer 1

试试这个

var customers = 
    from c in ctx.Customers 
    orderby c.CustomerRef ascending 
    select new { CustomerId = c.CustomerID, CustomerRef = c.CustomerRef }).ToList(); 

customers.Insert(0, new { CustomerID = -1, CustomerRef = "[Please Select]"}); 

cboCustomerRef.DataSource = customers; 
cboCustomerRef.ValueMember = "CustomerID"; 
cboCustomerRef.DisplayMember = "CustomerRef"; 

Answer 2

您可以使用下拉事件来检索您的数据，使 组合框

Customers.Text = [请选择]

默认情况下。