如何在asp.net页面中显示sql server 数据库图片字段的图片？

说明：在ASP中，我们用Request.TotalBytes、Request.BinaryRead()来上传图片，这个可恶的BinaryRead()方法非常笨，单个文件上传倒没什么大事，单如果多个图片上专可就花大气力了…！而现在ASP.Net中将会把解决以前ASP中文件上传的种种问题，使你在ASP.Net中轻轻松松开发出功能强大的上传程序，下面大家看看例子啦。首先在SQL Server中建立一个图片存储的数库表，SqlScript如下:if exists (select * from dbo.sysobjects where id = object_id(N"[dbo].[image]") and OBJECTPROPERTY(id, N"IsUserTable") = 1)
drop table [dbo].[image]
GOCREATE TABLE [dbo].[image] (
[img_pk] [int] IDENTITY (1, 1) NOT NULL ,
[img_name] [varchar] (50) NULL ,
[img_data] [image] NULL ,
[img_contenttype] [varchar] (50) NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GOALTER TABLE [dbo].[image] WITH NOCHECK ADD
CONSTRAINT [PK_image] PRIMARY KEY  NONCLUSTERED
(
  [img_pk]
)  ON [PRIMARY]
GO
------------------------------------------------------------
一、上传图片:
imgupload.aspx文件:
<%@ Page language="c#" Codebehind="imgupload.aspx.cs" AutoEventWireup="false" Inherits="study.uploadimage.imgupload" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
  <title>imgupload</title>
  <meta name="GENERATOR" Content="Microsoft Visual Studio 7.0">
  <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>
  <form enctype="multipart/form-data" runat="server" id="form1" name="form1">
   文件名 <input type="text" id="imgName" runat="server" NAME="imgName">
   <br>
   选择文件 <input id="UploadFile" type="file" runat="server" NAME="UploadFile">
   <br>
   <asp:button Text="上传" runat="server" ID="Button1" />
  </form>
  <a href="imgview.aspx?id=1" target="_blank">看图</a>
</body>
</HTML>codebehind文件:
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 study.uploadimage
{
/// <summary>
/// imgupload 的摘要说明。
/// </summary>
public class imgupload : System.Web.UI.Page
{
  protected System.Web.UI.WebControls.Button Button1;
  protected System.Web.UI.HtmlControls.HtmlInputText imgName;
  protected System.Web.UI.HtmlControls.HtmlInputFile UploadFile;

  private void Page_Load(object sender, System.EventArgs e)
  {
   // 在此处放置用户代码以初始化页面
  }  private void Button1_Click(object sender, System.EventArgs e)
  {
   Stream imgStream;
   int imgLen;
   string imgName_value;
   string imgContentType;
   string imgUploadedName;

   imgStream  = UploadFile.PostedFile.InputStream;
   imgLen =  UploadFile.PostedFile.ContentLength;
   imgUploadedName = UploadFile.PostedFile.FileName;
   byte[] imgBinaryData=new byte[imgLen];
   imgContentType = UploadFile.PostedFile.ContentType;
   imgName_value = imgName.Value;   try
   {
    if(imgName_value.Length < 1)
    {
     imgName_value = GetLastRightOf("file:/// );
    }
   }
   catch(Exception myEx)
   {
    Response.Write(myEx.Message);
   }   int n = imgStream.Read(imgBinaryData, 0, imgLen);
   int NumRowsAffected = MyDatabaseMethod(imgName_value, imgBinaryData, imgContentType);
            if(NumRowsAffected > 0)
             Response.Write( "<BR> uploaded image " );
   else
             Response.Write ( "<BR> an error occurred uploading the image.d " );
  }
  public string GetLastRightOf(string LookFor,string myString)
  {
   int StrPos;
   StrPos = myString.LastIndexOf(LookFor);
   return myString.Substring(StrPos + 1);
  }
  public int MyDatabaseMethod(string imgName,byte[] imgbin,string imgcontenttype)
  {
   SqlConnection connection = new SqlConnection(Application["Test_Conn"].ToString());
   string SQL="INSERT INTO Image (img_name,img_data,img_contenttype) VALUES ( @img_name, @img_data,@img_contenttype )";
   SqlCommand command=new SqlCommand ( SQL,connection );

   SqlParameter param0=new SqlParameter ( "@img_name", SqlDbType.VarChar,50 );
   param0.Value = imgName;
   command.Parameters.Add( param0 );               SqlParameter param1=new SqlParameter ( "@img_data", SqlDbType.Image );
   param1.Value = imgbin;
   command.Parameters.Add( param1 );

   SqlParameter param2 =new SqlParameter ( "@img_contenttype", SqlDbType.VarChar,50 );
   param2.Value = imgcontenttype;
   command.Parameters.Add( param2 );

   connection.Open();
   int numRowsAffected = command.ExecuteNonQuery();
   connection.Close();
   return numRowsAffected;
  }  #region Web Form Designer generated code
  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.Load += new System.EventHandler(this.Page_Load);  }
  #endregion
}
}------------------------------------------------------------二、浏览图片：
imgvies.aspx文件：
<%@ Page language="c#" Codebehind="imgview.aspx.cs" AutoEventWireup="false" Inherits="study.uploadimage.imgview" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
  <title>imgview</title>
  <meta name="GENERATOR" Content="Microsoft Visual Studio 7.0">
  <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">
</body>
</HTML>codebehind文件：
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.Data.SqlClient;namespace study.uploadimage
{
/// <summary>
/// imgview 的摘要说明。
/// </summary>
public class imgview : System.Web.UI.Page
{

  private void Page_Load(object sender, System.EventArgs e)
  {
   SqlConnection myDSN = new SqlConnection(Application["Test_Conn"].ToString());
   myDSN.Open();   int imgid = int.Parse(Request.QueryString["id"]);
   string sqlText = "SELECT img_name, img_data, img_contenttype FROM image where img_pk=" + imgid;
   Trace.Write(sqlText);
   SqlCommand MyCommand = new SqlCommand (sqlText, myDSN);
   SqlDataReader dr =MyCommand.ExecuteReader();
   if(dr.Read())
   {
    Response.ContentType = (dr["img_contenttype"].ToString());
    Response.BinaryWrite((byte[])dr["img_data"]);
   }
   myDSN.Close();
  }  #region Web Form Designer generated code
  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.Load += new System.EventHandler(this.Page_Load);  }
  #endregion
}
}
这样这个程序就完成了，简单吧。当然还很多改进之处，希望大家多想想多编编一定可以写出更多的图象上传程序。

调试易

如何在asp.net页面中显示sql server 数据库图片字段的图片？

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