第三十讲 : 综合应用&存储过程 返回值参数实例

建个表先：

CREATE TABLE [dbo].[Blogs]([blog_id] [int] IDENTITY(1,1) NOT NULL,--博客ID[blog_name] [varchar](50) NOT NULL, --博客标题[blog_content] [text] NOT NULL --博客内容）

插些数据进去后，创建一个存储过程：

 create proc ReturnValue  (@id int, --查寻条件@name varchar(100) output --要返回去的  )  as   select @name =(select blog_name from Blogs where blog_id=@id)  go

测试原码：

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Data.SqlClient;namespace ReturnValue{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        //连接字符串        string strConn = "server=.; database=hrms; uid=sa; pwd=123123";        string str = "select blog_id,blog_name,blog_content from [Blogs]";        private void Form1_Load(object sender, EventArgs e)        {            using (SqlConnection conn = new SqlConnection(strConn))            {                SqlCommand cmd = new SqlCommand(str, conn);                cmd.CommandType = CommandType.Text;                conn.Open();                SqlDataReader sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);                while (sdr.Read())                {                    ListViewItem lvi = new ListViewItem(sdr["blog_id"].ToString());                    lvi.SubItems.Add(sdr["blog_name"].ToString());                    lvi.SubItems.Add(sdr["blog_content"].ToString());                    listView1.Items.Add(lvi);                }                sdr.Close();            }        }        /// <summary>        /// 测试返回值        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private void button1_Click(object sender, EventArgs e)        {            int id=0;            try            {                id = Convert.ToInt32(tbValue.Text.Trim());            }            catch (Exception ex)            {                MessageBox.Show(ex.Message);            }            using (SqlConnection conn = new SqlConnection(strConn))            {                SqlCommand cmd = new SqlCommand("ReturnValue", conn);                cmd.CommandType = CommandType.StoredProcedure;                conn.Open();                cmd.Parameters.AddWithValue("@id",id);                // 下面的是定义一个返回值变量                SqlParameter name = new SqlParameter("@name",SqlDbType.VarChar,50);                name.Direction = ParameterDirection.Output;                cmd.Parameters.Add(name);                cmd.ExecuteNonQuery();                lblReturn.Text = cmd.Parameters["@name"].Value.ToString();            }        }        /// <summary>        /// 用户单击时，将自动ID填写到查寻条件框里        /// 多些一举不？呵呵，因为我实在不想手动输入        /// 你可以手输的        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private void listView1_SelectedIndexChanged(object sender, EventArgs e)        {            if (listView1.SelectedItems.Count > 0)            {                 foreach(ListViewItem lvi in listView1.SelectedItems)                {                    tbValue.Text = lvi.Text;                   }            }        }    }}

结果如图：