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