如何把保存在数据中image字段的图片文件，显示出来？

Response.ContentType = "图片类型";
Response.BinaryWrite((byte[])Reader["img字段"]);

解决方案 »

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Reader是什么类型？？说具体一点，多谢
SqlDataReader Reader = SqlCom.ExecuteReader();不会吧老大我举个例子而已。。
那如何实现别的类型的文件的操作，如word,execl。另外能不能说一下比SqlDataReader更强大的记录集对象。我是菜手，请多包含
对！要注意ContentType！
存的时候注意也存ContentType！
那存什么显示什么很方便！
什么WORD，XLS没有问题！
<%@Language=VBScript %><%dim AttID '附件内码AttID=trim(Request.QueryString("AttID"))
'设置文件的大小及MIME类型
Function SetForDisplay(field, contentType)
contentType = LCase(trim(contentType))
nFieldSize = field.ActualSize
bytes = field.GetChunk(nFieldSize)
Session("Bytes") = bytes
Session("Type") = contentType
End Function
dim oRs,sSqlsSql="select * from T_OA_DocAttach where gwfjid="&AttIDSet oRS = Server.CreateObject("ADODB.Recordset")oRs.Open sSql,cn,2,3if oRs.EOF=false then SetForDisplay oRs("gwfjnr"),oRs("gwfjlx")

'读取数据库中保存的内容
    response.Expires = 0
    response.Buffer  = True
    response.Clear
    response.contentType = Session("Type")
    Response.AddHeader "Content-Disposition", "attachment; filename=" & oRs("gwfjmc")
    response.BinaryWrite Session("Bytes")
    Session("Type") = ""
    Session("Bytes") = ""    set oRs=Nothing
    Response.Write "<script language='javascript'>window.close()</script>"
    response.End

'常见文件的MIME类型
'GIF文件  "image/gif"
'BMP文件 "image/bmp"
'JPG文件 "image/jpeg"
'zip文件 "application/x-zip-compressed"
'DOC文件 "application/msword"
'文本文件 "text/plain"
'HTML文件 "text/html"
'一般文件 "application/octet-stream"

end if

%>
ASP。NET下如何上传图片到数据库，并且读出图片
首先在SQL Server中建立一个图片存储的数库表，ImageData Column为图象二进制数据储存字段，ImageContentType Column为图象文件类型记录字段，ImageDescription Column为储蓄图象文件说明字段,ImageSize Column为储存图象文件长度字段，结构如下：
CREATE TABLE [dbo].[ImageStore] (
    [ImageID] [int] IDENTITY (1, 1) NOT NULL ,
    [ImageData] [image] NULL ,
    [ImageContentType] [varchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,
    [ImageDescription] [varchar] (200) COLLATE Chinese_PRC_CI_AS NULL ,
    [ImageSize] [int] NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
*/ //UpLoadImage.aspx程序内容如下：
<%@ Page Inherits="UploadImage.UploadImage" SRC="UpLoadImage.cs" Language="C#"%>
<HTML><title>上传图片</title>
<BODY bgcolor="#FFFFFF">
<FORM ENCTYPE="multipart/form-data" RUNAT="server" ID="Form1">
<TABLE RUNAT="server" WIDTH="700" ALIGN="left" ID="Table1" cellpadding="0" cellspacing="0" border="0">
<TR>
     <TD>上传图片(选择你要上传的图片)</TD>
<TD>
<INPUT TYPE="file" ID="UP_FILE" RUNAT="server" STYLE="Width:320" ACCEPT="text/*" NAME="UP_FILE">
</TD>
</TR>
<TR>
     <TD>
      文件说明(添加上传图片说明，如：作者、出处)
     </TD>
<TD>
<asp:TextBox RUNAT="server" WIDTH="239" ID="txtDescription" MAINTAINSTATE="false" />
</TD>
</TR>
<TR>
<TD>
<asp:Label RUNAT="server" ID="txtMessage" FORECOLOR="red" MAINTAINSTATE="false" />
</TD>
<TD>
<asp:Button RUNAT="server" WIDTH="239" onCLICK="Button_Submit" TEXT="Upload Image" />
</TD>
</TR>
</TABLE>
</FORM>
</BODY>
</HTML>
//-------------------------------------------------------------------
//UpLoadImage.cs程序内容如下：
using System;
using System.Web;
using System.IO;
using System.Data;
using System.Data.SqlClient;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace UploadImage
{
public class UploadImage : Page {
protected HtmlInputFile UP_FILE;          //HtmlControl、WebControls控件对象
protected TextBox txtDescription;
protected Label txtMessage;
protected Int32 FileLength = 0;          //记录文件长度变量
protected void Button_Submit(System.Object sender, System.EventArgs e) {
HttpPostedFile UpFile = UP_FILE.PostedFile;  //HttpPostedFile对象，用于读取图象文件属性
FileLength = UpFile.ContentLength;     //记录文件长度
try {
if (FileLength == 0) {   //文件长度为零时
txtMessage.Text = "<b>请你选择你要上传的文件</b>";
} else {
Byte[] FileByteArray = new Byte[FileLength];   //图象文件临时储存Byte数组
Stream StreamObject = UpFile.InputStream;      //建立数据流对像
//读取图象文件数据，FileByteArray为数据储存体，0为数据指针位置、FileLnegth为数据长度
StreamObject.Read(FileByteArray,0,FileLength);
//建立SQL Server链接
SqlConnection Con = new SqlConnection("Data Source=Localhost;Initial Catalog=testdb;User ID=sa;Pwd=;");
String SqlCmd = "INSERT INTO ImageStore (ImageData, ImageContentType, ImageDescription, ImageSize) valueS (@Image, @ContentType, @ImageDescription, @ImageSize)";
SqlCommand CmdObj = new SqlCommand(SqlCmd, Con);
CmdObj.Parameters.Add("@Image",SqlDbType.Binary, FileLength).value = FileByteArray;
CmdObj.Parameters.Add("@ContentType", SqlDbType.VarChar,50).value = UpFile.ContentType;  //记录文件类型
//把其它单表数据记录上传
CmdObj.Parameters.Add("@ImageDescription", SqlDbType.VarChar,200).value = txtDescription.Text;
//记录文件长度，读取时使用
CmdObj.Parameters.Add("@ImageSize", SqlDbType.BigInt,8).value = UpFile.ContentLength;
Con.Open();
CmdObj.ExecuteNonQuery();
Con.Close();
txtMessage.Text = "<p><b>OK!你已经成功上传你的图片</b>";//提示上传成功
}
} catch (Exception ex) {
txtMessage.Text = ex.Message.ToString();
}}}}
//----------------------------------------------------------------------
//好了，图片已经上传到数据库，现在还要干什么呢？当然是在数据库中读取及显示在Web页中啦,请看以下程序:
//ReadImage.aspx程序内容如下：
/-----------------------------------------------------------------------
<%@ Page Inherits="ReadImage.MainDisplay" SRC="ReadImage.cs"%>
//----------------------------------------------------------------------
//ReadImage.cs程序内容如下：
using System;
using System.Data;
using System.Data.SqlClient;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace ReadImage {
public class MainDisplay : System.Web.UI.Page {
public void Page_Load(System.Object sender, System.EventArgs e) {
    int ImgID = Convert.ToInt32(Request.QueryString["ImgID"]);  //ImgID为图片ID
    //建立数据库链接
    SqlConnection Con = new SqlConnection("Data Source=KING;Initial Catalog=testdb;User ID=sa;Pwd=;");
    String SqlCmd = "SELECT * FROM ImageStore WHERE ImageID = @ImageID";
    SqlCommand CmdObj = new SqlCommand(SqlCmd, Con);
    CmdObj.Parameters.Add("@ImageID", SqlDbType.Int).value = ImgID;
    Con.Open();
    SqlDataReader SqlReader = CmdObj.ExecuteReader();
    SqlReader.Read();
    Response.ContentType = (string)SqlReader["ImageContentType"];//设定输出文件类型
    //输出图象文件二进制数制
    Response.OutputStream.Write((byte[])SqlReader["ImageData"], 0, (int)SqlReader["ImageSize"]);
    Response.End();
    Con.Close();
    //很简单吧^_^
}
}
}
//--------------------------------------------------------------------
//最后，我们当然要把它在Web页面显示出来啦
//ShowImage.hml
<html>
<body>
这个是从数据库读取出来的图象：<img src="ReadImage.aspx?ImgID=1">
<body>
</html>
把图像文件上传到数据库，并从数据库读出
采用参数
上传图片到数据库:using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
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;namespace myUpLoad
{
/// <summary>
/// img2sql 的摘要说明。
/// </summary>
public class img2sql : System.Web.UI.Page
{
protected System.Web.UI.WebControls.TextBox imgTitleTextBox;
protected System.Web.UI.HtmlControls.HtmlInputFile upLoadImg;
protected System.Web.UI.WebControls.RequiredFieldValidator RequiredFieldValidator1;
protected System.Web.UI.WebControls.Button Button1;
protected SqlConnection myConnection;private void Page_Load(object sender, System.EventArgs e)
{
// 在此处放置用户代码以初始化页面
string conn="server=(local);database=test;uid=sa;pwd=ilovenm";
myConnection=new SqlConnection(conn);
}#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);}
#endregionprivate void Button1_Click(object sender, System.EventArgs e)
{
Stream myStream=upLoadImg.PostedFile.InputStream;
int imgDataLen=upLoadImg.PostedFile.ContentLength;
string imgType=upLoadImg.PostedFile.ContentType;
string imgTitle=imgTitleTextBox.Text;
byte[] imgData=new byte[imgDataLen];
int n=myStream.Read(imgData,0,imgDataLen);//string conn="server=(local);database=test;uid=sa;pwd=ilovenm";
//SqlConnection myConnection=new SqlConnection(conn);SqlCommand myCommand = new SqlCommand("INSERT INTO image (imgtitle,imgtype,imgdata) valueS ( @imgtitle, @imgtype, @imgdata )", myConnection);myCommand.Parameters.Add(new SqlParameter("@imgtitle",SqlDbType.VarChar,50));
myCommand.Parameters["@imgtitle"].value=imgTitle;myCommand.Parameters.Add(new SqlParameter("@imgtype",SqlDbType.VarChar,50));
myCommand.Parameters["@imgtype"].value=imgType;myCommand.Parameters.Add(new SqlParameter("@imgdata",SqlDbType.Image));
myCommand.Parameters["@imgdata"].value=imgData;myConnection.Open();
int numRowsAffected=myCommand.ExecuteNonQuery();
myConnection.Close();
}
}
}显示:
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;namespace myUpLoad
{
/// <summary>
/// showimg 的摘要说明。
/// </summary>
public class showimg : System.Web.UI.Page
{
protected SqlConnection myConnection;private void Page_Load(object sender, System.EventArgs e)
{
// 在此处放置用户代码以初始化页面
string imgID=Request.QueryString["imgid"];
string conn="server=(local);database=test;uid=sa;pwd=ilovenm";
//string conn="server=(local);database=test;uid=sa;pwd=ilovenm";
            myConnection=new SqlConnection(conn);string selectCmd="select imgdata,imgtype from image where id="+imgID;
SqlCommand myCommand=new SqlCommand(selectCmd,myConnection);
myConnection.Open();
SqlDataReader myDataReader=myCommand.ExecuteReader();if (myDataReader.Read())
{
Response.ContentType=myDataReader["imgtype"].ToString();
Response.BinaryWrite((byte[])myDataReader["imgdata"]);
}
}#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
}
}