namespace WebApplication2
{
public partial class ReadImage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string strImageID = Request.QueryString["id"];
SqlConnection myConnection = new SqlConnection("Data Source=.;Initial Catalog=northwind;User Id=sa;Password=123456;");
SqlCommand myCommand = new SqlCommand("Select Picture from Categories Where CategoryID="
+ strImageID, myConnection);

try
{
myConnection.Open();
SqlDataReader myDataReader;
myDataReader = myCommand.ExecuteReader(CommandBehavior.CloseConnection);
if (myDataReader.Read())
{
Response.Clear();

Response.ContentType = "image/jpeg";
byte[] b = (byte[])myDataReader["Picture"];
//下面的方法就是用来让图片可以正常显示
byte[] temp=new byte [b.Length -78];
Array.Copy(b, 78, temp, 0, b.Length - 78);
Response.BinaryWrite(temp);
}
myConnection.Close();
}
catch (SqlException SQLexc)
{
Response.Write(SQLexc.ToString ());
}
Response.End();

}
}
}

在源页面如Default.aspx.cs可以通过下面方法调用
代码如下:
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack )
Image1.ImageUrl = FormatURL("1");

}
protected string FormatURL(string strArgument)
{
return "ReadImage.aspx?id=" + strArgument;
}

如果不想新建一个页面来承载图像，也可以使用下面的方法：（注意：下面的类是自定义的，大家看得懂这个方法就可以了）
代码如下:
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;

namespace WebApplication2
{
public partial class ReadImage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string strImageID = Request.QueryString["id"];
SqlConnection myConnection = new SqlConnection("Data Source=.;Initial Catalog=northwind;User Id=sa;Password=123456;");
SqlCommand myCommand = new SqlCommand("Select Picture from Categories Where CategoryID="
+ strImageID, myConnection);

try
{
myConnection.Open();
SqlDataReader myDataReader;
myDataReader = myCommand.ExecuteReader(CommandBehavior.CloseConnection);
if (myDataReader.Read())
{
Response.Clear();

Response.ContentType = "image/jpeg";
byte[] b = (byte[])myDataReader["Picture"];
byte[] temp=new byte [b.Length -78];
Array.Copy(b, 78, temp, 0, b.Length - 78);
Response.BinaryWrite(temp);
}
myConnection.Close();
}
catch (SqlException SQLexc)
{
Response.Write(SQLexc.ToString ());
}
Response.End();

}
}
}