业务逻辑>数据层>SqlDataSource>sql的输入输出参数：
输入参数包括，控件参数，窗体参数，用户设置文件参数，查询字符串参数，会话参数，Cookie参数，后台代码声明参数。
输出参数包括，存储过程声明的输出参数，sql语句声明的输出参数。
参数类型。
业务逻辑>数据层>SqlDataSource>sql的输入输出参数>存储过程 输出参数：
改编自《ASP.NET3.5 开发范例精讲精析 基于c#》
首先是表结构
存储过程的代码
1 ALTER PROCEDURE dbo.Demo10simple
2 /*
3 (
4 @parameter1 int = 5,
5 @parameter2 datatype OUTPUT
6 )
7 */
8 @average money output,
9 @maximum money output,
10 @minimum money output
11 AS
12 /* SET NOCOUNT ON */
13 select @average = avg(当前薪资),@maximum=max(当前薪资),@minimum=min(当前薪资)
14 from 章立民研究室
15 where 部门='生产制造部';
16
17 select 员工号码,姓名,地址,当前薪资,部门
18 from 章立民研究室
19 where 部门='生产制造部';
20
21 --存储过程的返回值
22 RETURN @@rowcount;
23
2 /*
3 (
4 @parameter1 int = 5,
5 @parameter2 datatype OUTPUT
6 )
7 */
8 @average money output,
9 @maximum money output,
10 @minimum money output
11 AS
12 /* SET NOCOUNT ON */
13 select @average = avg(当前薪资),@maximum=max(当前薪资),@minimum=min(当前薪资)
14 from 章立民研究室
15 where 部门='生产制造部';
16
17 select 员工号码,姓名,地址,当前薪资,部门
18 from 章立民研究室
19 where 部门='生产制造部';
20
21 --存储过程的返回值
22 RETURN @@rowcount;
23
你看，@average,@maximum,@minimum 声明为输出参数，然后把sql函数对字段的操作结果赋予这些输出参数。
这里还有个特殊的输出参数，就是存储过程的返回值。
网页前台代码：
1 <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Demo10simple.aspx.cs" Inherits="Demo10simple" %>
2
3 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
4
5 <html xmlns="http://www.w3.org/1999/xhtml">
6 <head runat="server">
7 <title>存储过程的输出参数与返回值</title>
8 </head>
9 <body>
10 <form id="form1" runat="server">
11 <div>
12
13 <asp:GridView ID="GridView1" runat="server" DataSourceID="SqlDataSource1">
14 </asp:GridView>
15 <asp:SqlDataSource ID="SqlDataSource1" runat="server"
16 ConnectionString="<%$ ConnectionStrings:ChtNorthwind %>"
17 SelectCommand="Demo10simple" SelectCommandType="StoredProcedure"
18 onselected="SqlDataSource1_Selected">
19
20 <SelectParameters>
21 <asp:Parameter Direction="Output" Name="average" Type="Decimal" />
22 <asp:Parameter Direction="Output" Name="maximum" Type="Decimal" />
23 <asp:Parameter Direction="Output" Name="minimum" Type="Decimal" />
24 <asp:Parameter Direction="ReturnValue" Name="ret" Type="Int32" />
25 </SelectParameters>
26
27 </asp:SqlDataSource>
28
29 <br />
30 <asp:TextBox ID="TextBox1" runat="server" Width="380px"></asp:TextBox>
31 <br />
32 <asp:TextBox ID="TextBox2" runat="server" Width="380px"></asp:TextBox>
33 <br />
34 <asp:TextBox ID="TextBox3" runat="server" Width="380px"></asp:TextBox>
35 <br />
36 <asp:TextBox ID="TextBox4" runat="server" Width="380px"></asp:TextBox>
37 </div>
38 </form>
39 </body>
40 </html>
41
2
3 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
4
5 <html xmlns="http://www.w3.org/1999/xhtml">
6 <head runat="server">
7 <title>存储过程的输出参数与返回值</title>
8 </head>
9 <body>
10 <form id="form1" runat="server">
11 <div>
12
13 <asp:GridView ID="GridView1" runat="server" DataSourceID="SqlDataSource1">
14 </asp:GridView>
15 <asp:SqlDataSource ID="SqlDataSource1" runat="server"
16 ConnectionString="<%$ ConnectionStrings:ChtNorthwind %>"
17 SelectCommand="Demo10simple" SelectCommandType="StoredProcedure"
18 onselected="SqlDataSource1_Selected">
19
20 <SelectParameters>
21 <asp:Parameter Direction="Output" Name="average" Type="Decimal" />
22 <asp:Parameter Direction="Output" Name="maximum" Type="Decimal" />
23 <asp:Parameter Direction="Output" Name="minimum" Type="Decimal" />
24 <asp:Parameter Direction="ReturnValue" Name="ret" Type="Int32" />
25 </SelectParameters>
26
27 </asp:SqlDataSource>
28
29 <br />
30 <asp:TextBox ID="TextBox1" runat="server" Width="380px"></asp:TextBox>
31 <br />
32 <asp:TextBox ID="TextBox2" runat="server" Width="380px"></asp:TextBox>
33 <br />
34 <asp:TextBox ID="TextBox3" runat="server" Width="380px"></asp:TextBox>
35 <br />
36 <asp:TextBox ID="TextBox4" runat="server" Width="380px"></asp:TextBox>
37 </div>
38 </form>
39 </body>
40 </html>
41
SqlDataSource 的查询方法设置成存储过程，声明几个参数为输出参数，名字对应存储过程的输出参数，并且设置好类型。
后台代码：
1 using System;
2 using System.Collections;
3 using System.Configuration;
4 using System.Data;
5 using System.Linq;
6 using System.Web;
7 using System.Web.Security;
8 using System.Web.UI;
9 using System.Web.UI.HtmlControls;
10 using System.Web.UI.WebControls;
11 using System.Web.UI.WebControls.WebParts;
12 using System.Xml.Linq;
13 using System.Data.SqlClient;
14
15 public partial class Demo10simple : System.Web.UI.Page
16 {
17 protected void Page_Load(object sender, EventArgs e)
18 {
19
20 }
21 protected void SqlDataSource1_Selected(object sender, SqlDataSourceStatusEventArgs e)
22 {
23 IDbCommand cmd = e.Command;
24
25 SqlParameter Return_Param;
26 SqlParameter Average_Param;
27 SqlParameter Maximum_Param;
28 SqlParameter Minimum_Param;
29
30 Return_Param = (SqlParameter)cmd.Parameters["@ret"];
31 Average_Param = (SqlParameter)cmd.Parameters["@average"];
32 Maximum_Param = (SqlParameter)cmd.Parameters["@maximum"];
33 Minimum_Param = (SqlParameter)cmd.Parameters["@minimum"];
34
35 this.TextBox1.Text = "输出参数名称：" + Average_Param.ParameterName + "，参数值（平均薪资）：" + Average_Param.Value.ToString();
36 this.TextBox2.Text = "输出参数名称：" + Maximum_Param.ParameterName + "，参数值（最高薪资）：" + Maximum_Param.Value.ToString();
37 this.TextBox3.Text = "输出参数名称：" + Minimum_Param.ParameterName + "，参数值（最低薪资）：" + Minimum_Param.Value.ToString();
38 this.TextBox4.Text = "存储过程返回值参数名称：" + Return_Param.ParameterName + "，参数值（人数）：" + Return_Param.Value.ToString();
39 }
40 }
41
2 using System.Collections;
3 using System.Configuration;
4 using System.Data;
5 using System.Linq;
6 using System.Web;
7 using System.Web.Security;
8 using System.Web.UI;
9 using System.Web.UI.HtmlControls;
10 using System.Web.UI.WebControls;
11 using System.Web.UI.WebControls.WebParts;
12 using System.Xml.Linq;
13 using System.Data.SqlClient;
14
15 public partial class Demo10simple : System.Web.UI.Page
16 {
17 protected void Page_Load(object sender, EventArgs e)
18 {
19
20 }
21 protected void SqlDataSource1_Selected(object sender, SqlDataSourceStatusEventArgs e)
22 {
23 IDbCommand cmd = e.Command;
24
25 SqlParameter Return_Param;
26 SqlParameter Average_Param;
27 SqlParameter Maximum_Param;
28 SqlParameter Minimum_Param;
29
30 Return_Param = (SqlParameter)cmd.Parameters["@ret"];
31 Average_Param = (SqlParameter)cmd.Parameters["@average"];
32 Maximum_Param = (SqlParameter)cmd.Parameters["@maximum"];
33 Minimum_Param = (SqlParameter)cmd.Parameters["@minimum"];
34
35 this.TextBox1.Text = "输出参数名称：" + Average_Param.ParameterName + "，参数值（平均薪资）：" + Average_Param.Value.ToString();
36 this.TextBox2.Text = "输出参数名称：" + Maximum_Param.ParameterName + "，参数值（最高薪资）：" + Maximum_Param.Value.ToString();
37 this.TextBox3.Text = "输出参数名称：" + Minimum_Param.ParameterName + "，参数值（最低薪资）：" + Minimum_Param.Value.ToString();
38 this.TextBox4.Text = "存储过程返回值参数名称：" + Return_Param.ParameterName + "，参数值（人数）：" + Return_Param.Value.ToString();
39 }
40 }
41
在SqlDataSource的selected事件中，来获取输出参数的值，并赋值给页面上其它控件的属性。
输出参数还是很用，有些直接在数据库里的运算结果，比如最大，最小，平均，可以输出到逻辑代码里，然后调用。