第一重:单个图片上传到数据库
这个问题已经不是什么新鲜问题了,网上也有大把的教程,但大多数是授人以鱼,而不授人以渔,经过辛苦的资料收集,思考,调试,整理,我基本上已经把这个问题从原理上搞清楚了,现在根据我自己的理解,在范例程序的基础上,加以解释,希望能对部分网友(比我还菜的:-))有所帮助。
请诸位大虾能对其中的不正或不良这处予以指正。
程序中stream对象的用法上参考了“化境HTTP上传程序 Version 2.0”在代码,在此对稻香老农和梁无惧表示衷心的感谢和由衷的敬意。
我想循序渐进,今天先讲一个简单的,单个图片文件保存到数据库。
这个范例共包括三个ASP文件和一个数据库(一个表),全部在同一目录下。
1、tblImage 表结构(ACCESS 2000)
sn 自动编号 序列号 content-type 文本 图片类型 image OLE 对象 图片数据
2、SimpleImageToData.asp:上传表单及保存图片到数据库的代码部分,主要文件。
<%@ Language=VBScript %> <% option explicit %>
<% '从一个完整路径中析出文件名称 function getFileNamefromPath(strPath) getFileNamefromPath = mid(strPath,instrrev(strPath,"\")+1) end function
'定义数据库连接字符串 dim cnstr cnstr = "driver={Microsoft Access Driver (*.mdb)};dbq=" & server.MapPath("./upload.mdb") %>
<HTML> <HEAD> <title>单个图像保存到数据库</title> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> </HEAD> <body> <p><a href="SimpleImageToData.asp">上传图片</a> <a href="ShowImageListFromData.asp">显示图片</a><hr></p> <% if request.ServerVariables("REQUEST_METHOD") = "POST" then
dim sCome, sGo, binData, strData dim posB, posE, posSB, posSE dim binCrlf dim strPath, strFileName, strContentType binCrlf = chrb(13)&chrb(10) '定义一个单字节的回车换行符 set sCome = server.CreateObject("adodb.stream") sCome.Type = 1 '指定返回数据类型 adTypeBinary=1,adTypeText=2 sCome.Mode = 3 '指定打开模式 adModeRead=1,adModeWrite=2,adModeReadWrite=3 sCome.Open sCome.Write request.BinaryRead(request.TotalBytes) sCome.Position = 0 binData = sCome.Read 'response.BinaryWrite binData '调试用:显示提交的所有数据 'response.Write "<hr>" '调试用 set sGo = server.CreateObject("adodb.stream") sGo.Type = 1 sGo.Mode = 3 sGo.Open posB = 1 posB = instrb(posB,binData,binCrlf) posE = instrb(posB+1,binData,binCrlf) 'response.Write posB & " | " & posE & "<br>" sCome.Position = posB+1 sCome.CopyTo sGo,posE-posB-2 sGo.Position = 0 sGo.Type = 2 sGo.Charset = "gb2312" strData = sGo.ReadText sGo.Close 'response.Write strData & "<hr>" posSB = 1 posSB = instr(posSB,strData,"filename=""") + len("filename=""") posSE = instr(posSB,strData,"""") if posSE > posSB then strPath = mid(strData,posSB,posSE-posSB) 'response.Write "本地路径:" & strPath & "<br>" 'response.Write "文件名:" & getFileNamefromPath(strPath) & "<br>" posB = posE posE = instrb(posB+1,binData,binCrlf) 'response.Write posB & " | " & posE & "<br>" sGo.Type = 1 sGo.Mode = 3 sGo.Open
sCome.Position = posB sCome.CopyTo sGo,posE-posB-1
sGo.Position = 0 sGo.Type = 2 sGo.Charset = "gb2312" strData = sGo.ReadText sGo.Close strContentType = mid(strData,16) '此处因为固定的,所以省略查找 :-) 'response.Write "图片类型:" & strContentType & "<hr>" posB = posE+2 posE = instrb(posB+1,binData,binCrlf) 'response.Write posB & " | " & posE & "<br>" sGo.Type = 1 sGo.Mode = 3 sGo.Open
sCome.Position = posB+1 sCome.CopyTo sGo,posE-posB-2 sGo.Position = 0 strData = sGo.Read sGo.Close 'response.Write lenb(strData) & "<br>" dim cn, rs, sql set cn = server.CreateObject("adodb.connection") cn.Open cnstr set rs = server.CreateObject("adodb.recordset") sql = "select * from tblImage" rs.Open sql,cn,1,3 rs.AddNew rs.Fields("content-type").Value = strContentType rs.Fields("image").AppendChunk strData rs.Update rs.Close set rs = nothing cn.Close set cn = nothing response.Write "图片保存成功!" & "<br>" else response.Write "没有上传图片!" & "<br>" end if set sGo = nothing sCome.Close set sCome = nothing else %> <form id="frmUpload" name="frmUpload" action="SimpleImageToData.asp" method="post" target="_self" enctype="multipart/form-data"> <INPUT id="filImage" type="file" name="filImage" size="40"> <BR> <INPUT id="btnUpload" type="submit" value="Upload" name="btnUpload"> </form> <% end if %> </body> </HTML>
3、ShowImageListFromData.asp
<%@ Language=VBScript %> <% option explicit %>
<html> <head> <title>显示数据库中已有图片的列表</title> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> </head> <body> <p><a href="SimpleImageToData.asp">上传图片</a> <a href="ShowImageListFromData.asp">显示图片</a><hr></p> <table border=0 cellpadding=2 cellspacing=2> <tr> <td valign=top> <% dim cnstr cnstr = "driver={Microsoft Access Driver (*.mdb)};dbq=" & server.MapPath("./upload.mdb") dim cn, sql, rs set cn = server.CreateObject("adodb.connection") cn.Open cnstr sql = "select sn,[content-type],image from tblImage" set rs = cn.Execute(sql) response.Write "<table border=1 cellspacing=2 cellpadding=5>" response.Write "<tr>" response.Write "<th>序列号</th><th>图片类型</th><th>图片</th>" response.Write "</tr>" do until rs.eof response.Write "<tr>" response.Write "<td>" & rs("sn") & "</td>" response.Write "<td>" & rs("content-type") & "</td>" response.Write "<td><a href='ShowImageListFromData.asp?sn=" & rs("sn") & "'>看图</a></td>" response.Write "</tr>" rs.movenext loop response.Write "</table>" cn.Close set cn = nothing %> </td> <td valign=top> <% dim sn sn = request.QueryString("sn") if sn = "" then response.Write "没有指定图片!" else response.Write "<img border=1 src=ShowImageFromData.asp?sn=" & sn & ">" end if %> </td> </tr> </table> </body> </html>
4、ShowImageFromData.asp
<%@ Language=VBScript %> <% option explicit %>
<% dim sn sn = request.QueryString("sn") if sn = "" then response.End dim cnstr cnstr = "driver={Microsoft Access Driver (*.mdb)};dbq=" & server.MapPath("./upload.mdb") dim cn, sql, rs set cn = server.CreateObject("adodb.connection") cn.Open cnstr sql = "select sn,[content-type],image from tblImage where sn=" & cint(sn) set rs = cn.Execute(sql) response.ContentType = rs("content-type") response.BinaryWrite rs("image") set rs = nothing cn.Close set cn = nothing %>
待续... 
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