Asp：写入和读取图片（c＃ asp。net sqlserver）

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写入和读取图片（c＃ asp。net sqlserver）

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首先要创建一个表包含自段image 和 type 类型各自为image 和 vnanchar

WebForm1.aspx

<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="ReadAndWritePicFromDB.WebForm1" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" > <HTML> <HEAD> <title>WebForm1</title> <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1"> <meta name="CODE_LANGUAGE" Content="C#"> <meta name="vs_defaultClientScript" content="JavaScript"> <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5"> </HEAD> <body MS_POSITIONING="GridLayout"> <form id="Form1" method="post" runat="server"> <FONT face="宋体"><INPUT id="File1" style="Z-INDEX: 101; LEFT: 112px; POSITION: absolute; TOP: 88px" type="file" name="File1" runat="server"></FONT> <asp:Button id="Button1" style="Z-INDEX: 102; LEFT: 400px; POSITION: absolute; TOP: 88px" runat="server" Text="Write" Width="104px"></asp:Button> <asp:Button id="Button2" style="Z-INDEX: 103; LEFT: 552px; POSITION: absolute; TOP: 88px" runat="server" Text="Read" Width="105px"></asp:Button> </form> </body> </HTML>

WebForm1.aspx.cs

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.IO;
using System.Data.SqlClient;

namespace ReadAndWritePicFromDB
{
/// <summary>
/// WebForm1 的摘要说明。
/// </summary>
public class WebForm1 : System.Web.UI.Page
{
  protected System.Web.UI.HtmlControls.HtmlInputFile File1;
  protected System.Web.UI.WebControls.Button Button1;
  private string fileName = "" ;
  protected System.Web.UI.WebControls.Button Button2;
  private static SqlConnection conn = null;

  private void Page_Load(object sender, System.EventArgs e)
  {
   // 在此处放置用户代码以初始化页面
   ConnectDB();
  }

  //得到文件名
  private string GetFile()
  {
   HttpPostedFile file = File1.PostedFile;
   fileName = file.FileName;

return fileName;
}

  //读取文件内容
  private byte[] ReadFile()
  {
   FileStream file = File.OpenRead(GetFile());
   byte[] content = new byte[file.Length];
   file.Read(content,0,content.Length);
   file.Close();

   return content;
  }

  //连接数据库
  private void ConnectDB()
  {
   string connStr = "Initial Catalog=;Data Source=;User ID=;Password=;";
   conn = new SqlConnection(connStr);
   conn.Open();
  }

  //写入图片到数据库中
  private void WriteImage()
  {
   SqlCommand comm = conn.CreateCommand();
   comm.CommandText = "insert into images(image,type) values(@image,@type)";
   comm.CommandType = CommandType.Text;
   SqlParameter param = comm.Parameters.Add("@image",SqlDbType.Image);
   param.Value = ReadFile();
   param = comm.Parameters.Add("@type",SqlDbType.NVarChar);
   param.Value = GetContentType(new FileInfo(fileName).Extension.Remove(0,1));

   if(comm.ExecuteNonQuery() == 1)
    Response.Write("Successful");
   else
    Response.Write("Fail");

   conn.Close();
  }

  //获取图片的后缀名
  private string GetContentType(string extension)
  {
   string type = "";

   if(extension.Equals("jpg") || extension.Equals("JPG"))
    type = "jpeg";
   else
    type = extension;

return "image/"+type;
}

  //从数据库中读取图片
  private void ReadImage()
  {
   SqlCommand comm = conn.CreateCommand();
   comm.CommandText = "select image,type from images";
   comm.CommandType = CommandType.Text;

   SqlDataReader reader = comm.ExecuteReader();
   while(reader.Read())
   {
    Response.ContentType = reader["type"].ToString();//读写类型一定要设置否则浏览器会当作文本输出
    Response.BinaryWrite((byte[])reader["image"]);//图片数据
   }

Response.Write("Successful");
Response.End();

   conn.Close();
  }
  #region Web 窗体设计器生成的代码
  override protected void OnInit(EventArgs e)
  {
   //
   // CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
   //
   InitializeComponent();
   base.OnInit(e);
  }

  /// <summary>
  /// 设计器支持所需的方法 - 不要使用代码编辑器修改
  /// 此方法的内容。
  /// </summary>
  private void InitializeComponent()
  {
   this.Button1.Click += new System.EventHandler(this.Button1_Click);
   this.Button2.Click += new System.EventHandler(this.Button2_Click);
   this.Load += new System.EventHandler(this.Page_Load);

}
#endregion

  private void Button1_Click(object sender, System.EventArgs e)
  {
   WriteImage();
  }

  private void Button2_Click(object sender, System.EventArgs e)
  {
   try
   {
    ReadImage();
   }
   catch(Exception ep)
   {
    conn.Close();
    Response.End();
   }
  }
}
}

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