image类型的字段，取出来保存成一个文件的例子？急！

Question

image类型的字段，取出来保存成一个文件的例子？
是个图片文件。

Answer 1

SqlConnection pubsConn = new SqlConnection("Data Source=localhost;Integrated Security=SSPI;Initial Catalog=pubs;");
SqlCommand logoCMD = new SqlCommand("SELECT pub_id, logo FROM pub_info", pubsConn);FileStream fs;                          // Writes the BLOB to a file (*.bmp).
BinaryWriter bw;                        // Streams the BLOB to the FileStream object.int bufferSize = 100;                   // Size of the BLOB buffer.
byte[] outbyte = new byte[bufferSize];  // The BLOB byte[] buffer to be filled by GetBytes.
long retval;                            // The bytes returned from GetBytes.
long startIndex = 0;                    // The starting position in the BLOB output.string pub_id = "";                     // The publisher id to use in the file name.// Open the connection and read data into the DataReader.
pubsConn.Open();
SqlDataReader myReader = logoCMD.ExecuteReader(CommandBehavior.SequentialAccess);while (myReader.Read())
{
  // Get the publisher id, which must occur before getting the logo.
  pub_id = myReader.GetString(0);    // Create a file to hold the output.
  fs = new FileStream("logo" + pub_id + ".bmp", FileMode.OpenOrCreate, FileAccess.Write);
  bw = new BinaryWriter(fs);  // Reset the starting byte for the new BLOB.
  startIndex = 0;  // Read the bytes into outbyte[] and retain the number of bytes returned.
  retval = myReader.GetBytes(1, startIndex, outbyte, 0, bufferSize);  // Continue reading and writing while there are bytes beyond the size of the buffer.
  while (retval == bufferSize)
  {
    bw.Write(outbyte);
    bw.Flush();    // Reposition the start index to the end of the last buffer and fill the buffer.
    startIndex += bufferSize;
    retval = myReader.GetBytes(1, startIndex, outbyte, 0, bufferSize);
  }  // Write the remaining buffer.
  bw.Write(outbyte, 0, (int)retval - 1);
  bw.Flush();  // Close the output file.
  bw.Close();
  fs.Close();
}// Close the reader and the connection.
myReader.Close();
pubsConn.Close();

Answer 2

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.IO;public partial class upfile_ToDB_ShowPic : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string id = Request.QueryString["id"];
        if (id != null && id.CompareTo("") != 0)
        {
            string connStr = ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString;
            string SqlStr = "SELECT * FROM test02 where id = " + id;
            DataSet ds = new DataSet();            try
            {
                SqlConnection conn = new SqlConnection(connStr);
                if (conn.State.ToString() == "Closed") conn.Open();
                SqlDataAdapter da = new SqlDataAdapter(SqlStr, conn);
                da.Fill(ds, "test01");
                if (conn.State.ToString() == "Open") conn.Close();
                if (ds.Tables[0].Rows.Count > 0)
                {
                    Byte[] FileByteArray =(byte[])ds.Tables[0].Rows[0]["pic"];                    File.WriteAllBytes("d:\\a.jpg", FileByteArray);                    Response.BinaryWrite((byte[])ds.Tables[0].Rows[0]["pic"]);
                    Response.End();
                }
            }
            catch (Exception ex)
            {
                Response.Write("数据库错误，错误原因：" + ex.Message);
                Response.End();
            }
        }
    }
}
关键的2行:
Byte[] FileByteArray =(byte[])ds.Tables[0].Rows[0]["pic"];
File.WriteAllBytes("d:\\a.jpg", FileByteArray);