无法将方法组分配给 asp.net、linq、c# 中的隐式类型局部变量

public void selectqueryasso()
    {
        CustomerOrderResult cso=new CustomerOrderResult();
        var a = (from as1 in ds.orders
                   from as2 in ds.order_details
                   where (as1.oid == as2.oid)
                   orderby as1.pname
                   select new CustomerOrderResult 
                   {
                      oid = Convert.ToInt32(as1.oid),
                      cmny =as1.cmny,
                      ocountry=as1.ocountry,
                      pname=as1.pname,
                      price= Convert.ToString(as1.price),
                      orderno= Convert.ToString(as1.orderno),
                      saltitle=as1.saltitle
                   }).ToList<CustomerOrderResult>;

        GridView1.DataSource = a;
        GridView1.DataBind();
    }

无法将方法组分配给隐式类型的局部变量 无法将方法组分配给隐式类型的局部变量 无法将方法组分配给隐式类型的局部变量

你实际上并没有调用ToList()方法，你缺少括号：

public void selectqueryasso()
{
    CustomerOrderResult cso=new CustomerOrderResult();
    var a = (from as1 in ds.orders
               from as2 in ds.order_details
               where (as1.oid == as2.oid)
               orderby as1.pname
               select new CustomerOrderResult 
               {
                  oid = Convert.ToInt32(as1.oid),
                  cmny =as1.cmny,
                  ocountry=as1.ocountry,
                  pname=as1.pname,
                  price= Convert.ToString(as1.price),
                  orderno= Convert.ToString(as1.orderno),
                  saltitle=as1.saltitle
               }).ToList<CustomerOrderResult>();

    GridView1.DataSource = a;
    GridView1.DataBind();
}