C#从SqlServer数据库读写文件代码

2015/05/02 39989

C#从SqlServer数据库读写文件代码，可以将文件存储在数据库内，然后通过代码对文件进行读写

<%@ Page Language="C#" %>
  
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  private string connectionString = "Data Source=192.168.3.1;Initial Catalog=TestData;User Id=sa;Password=lambada;";
  protected void Button1_Click(object sender, EventArgs e)
  {
  //得到文件数组
  byte[] fileData = FileUpload1.FileBytes;
  //得到文件名字
  string fileName = System.IO.Path.GetFileName(FileUpload1.FileName);
  //得到文件类型
  string fileType = FileUpload1.PostedFile.ContentType;
  
  //构建数据库连接，SQL语句，创建参数
    
  System.Data.SqlClient.SqlConnection myConnection = new System.Data.SqlClient.SqlConnection(connectionString);
  String strSql = "INSERT INTO FileTable (ContentType,Content,Title)" +
  "VALUES (@ContentType,@Content,@Title)";
  System.Data.SqlClient.SqlCommand command = new System.Data.SqlClient.SqlCommand(strSql, myConnection);
  command.Parameters.AddWithValue("@ContentType", fileType);
  command.Parameters.AddWithValue("@Content", fileData);
  command.Parameters.AddWithValue("@Title", fileName);
  //打开连接，执行查询
  myConnection.Open();
  command.ExecuteNonQuery();
  myConnection.Close();
  myConnection.Dispose();
  Response.Redirect(Request.FilePath);
  }
  
  protected void Page_Load(object sender, EventArgs e)
  {
  /*
   CREATE TABLE [FileTable] (
    [FileId] [int] IDENTITY (1, 1) NOT NULL ,
    [Title] [nvarchar] (255) COLLATE Chinese_PRC_CI_AS NOT NULL ,
    [ContentType] [varchar] (50) COLLATE Chinese_PRC_CI_AS NOT NULL ,
    [Content] [image] NULL ,
    CONSTRAINT [PK_FileTable] PRIMARY KEY  CLUSTERED
    (
        [FileId]
    )  ON [PRIMARY]
  ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
  
  */
    
  //构建数据库连接，SQL语句，创建参数
  System.Data.SqlClient.SqlConnection myConnection = new System.Data.SqlClient.SqlConnection(connectionString);
  String strSql = "select * from FileTable";
  System.Data.SqlClient.SqlCommand command = new System.Data.SqlClient.SqlCommand(strSql, myConnection);
  //打开连接，执行查询
  myConnection.Open();
  System.Data.SqlClient.SqlDataReader dr = command.ExecuteReader();
  GridView1.DataSource = dr;
  GridView1.DataBind();
  myConnection.Close();
  myConnection.Dispose();
  }
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
  <title></title>
</head>
<body>
  <form id="form1" runat="server">
  <asp:FileUpload ID="FileUpload1" runat="server" />
  <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="上传文件" />
  <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
  <Columns>
  <asp:HyperLinkField DataNavigateUrlFields="FileId" HeaderText="文件名" DataTextField="Title" DataNavigateUrlFormatString="~/Download.ashx?FileId={0}" />
  </Columns>
  </asp:GridView>
  </form>
</body>
</html>

//Download.ashx

<%@ WebHandler Language="C#" Class="Download" %>
using System;
using System.Web;
using System.Data.SqlClient;
public class Download : IHttpHandler
{
  private string connectionString = "Data Source=192.168.3.1;Initial Catalog=TestData;User Id=sa;Password=lambada;";
  public void ProcessRequest(HttpContext context)
  {
    String fileId = context.Request.QueryString["FileId"];
    if (String.IsNullOrEmpty(fileId))
    {
      context.Response.ContentType = "text/html";
      context.Response.Write("无效的ID。");
      return;
    }
    int id = 0;
    if (!Int32.TryParse(fileId, out id))
    {
      context.Response.ContentType = "text/html";
      context.Response.Write("ID 不是数字。");
      return;
    }
  
    SqlConnection myConnection = new SqlConnection(connectionString);
    String strSql = "select * from FileTable Where FileId=@FileId";
    SqlCommand command = new SqlCommand(strSql, myConnection);
    command.Parameters.AddWithValue("@FileId", fileId);
    //打开连接，执行查询
    myConnection.Open();
    SqlDataReader dr = command.ExecuteReader();
    if (dr.Read())
    {
      String fileName = dr["Title"].ToString();
      if (context.Request.UserAgent.IndexOf("MSIE") > -1)
      {
        fileName = HttpUtility.UrlEncode(fileName);
      }
      context.Response.ClearContent();
      context.Response.ContentType = dr["ContentType"].ToString();
      context.Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
      context.Response.BinaryWrite((Byte[])dr["Content"]);
    }
    else
    {
      context.Response.ContentType = "text/html";
      context.Response.Write("没找到文件。");
    }
    myConnection.Close();
    myConnection.Dispose();
  }
  
  public bool IsReusable
  {
    get
    {
      return false;
    }
  }
  
}

代码片段