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至少有三种以上办法，可以把二进制数据（比如您从asp的request.binaryread方法得到的数据）转换为字符串。
第一种：使用vbs的multibyte 方法
实例：
function simplebinarytostring(binary)
simplebinarytostring converts binary data (vt_ui1 | vt_array or multibyte string)
to a string (bstr) using multibyte vbs functions
dim i, s
for i = 1 to lenb(binary)
s = s & chr(ascb(midb(binary, i, 1)))
next
simplebinarytostring = s
end function
这个方法非常简单明了，但是处理大数据流时，比较慢。
建议只用来处理100kb以下的数据。
下面的这个类似的方法，性能稍微好些：
function binarytostring(binary)
antonin foller, http://www.pstruh.cz
optimized version of a simple binarytostring algorithm.
dim cl1, cl2, cl3, pl1, pl2, pl3
dim l
cl1 = 1
cl2 = 1
cl3 = 1
l = lenb(binary)
do while cl1<=l
pl3 = pl3 & chr(ascb(midb(binary,cl1,1)))
cl1 = cl1 + 1
cl3 = cl3 + 1
if cl3>300 then
pl2 = pl2 & pl3
pl3 = ""
cl3 = 1
cl2 = cl2 + 1
if cl2>200 then
pl1 = pl1 & pl2
pl2 = ""
cl2 = 1
end if
end if
loop
binarytostring = pl1 & pl2 & pl3
end function
binarytostring方法比simplebinarytostring方法性能高20倍。建议用来处理2mb以下的数据。
第二种方法：使用adodb.recordset
adodb.recordset 可以让你支持几乎所有variant支持的数据类型，你可以用它在string和
binary之间转换。
function rsbinarytostring(xbinary)
antonin foller, http://www.pstruh.cz
rsbinarytostring converts binary data (vt_ui1 | vt_array or multibyte string)
to a string (bstr) using ado recordset
dim binary
multibyte data must be converted to vt_ui1 | vt_array first.
if vartype(xbinary)=8 then binary = multibytetobinary(xbinary) else binary = xbinary
dim rs, lbinary
const adlongvarchar = 201
set rs = createobject("adodb.recordset")
lbinary = lenb(binary)
if lbinary>0 then
rs.fields.append "mbinary", adlongvarchar, lbinary
rs.open
rs.addnew
rs("mbinary").appendchunk binary
rs.update
rsbinarytostring = rs("mbinary")
else
rsbinarytostring = ""
end if
end function
rsbinarytostring 没有什么限制–除了物理内存之外。这种处理方式是multibyte方式的100倍！你可以用它来处理高达100mb的数据！ 这种转换方式，你也可以用来把multibyte strings转换为string。下面这个方法把multibyte strings转换为binary：function multibytetobinary(multibyte)
© 2000 antonin foller, http://www.pstruh.cz
multibytetobinary converts multibyte string to real binary data (vt_ui1 | vt_array)
using recordset
dim rs, lmultibyte, binary
const adlongvarbinary = 205
set rs = createobject("adodb.recordset")
lmultibyte = lenb(multibyte)
if lmultibyte>0 then
rs.fields.append "mbinary", adlongvarbinary, lmultibyte
rs.open
rs.addnew
rs("mbinary").appendchunk multibyte & chrb(0)
rs.update
binary = rs("mbinary").getchunk(lmultibyte)
end if
multibytetobinary = binary
end function
第三种：使用adodb.stream这种方式是比较常用的：stream_binarytostring function
2003 antonin foller, http://www.pstruh.cz
binary – vt_ui1 | vt_array data to convert to a string
charset – charset of the source binary data – default is "us-ascii"
function stream_binarytostring(binary, charset)
const adtypetext = 2
const adtypebinary = 1
create stream object
dim binarystream as new stream
set binarystream = createobject("adodb.stream")
specify stream type – we want to save text/string data.
binarystream.type = adtypebinary
open the stream and write text/string data to the object
binarystream.open
binarystream.write binary
change stream type to binary
binarystream.position = 0
binarystream.type = adtypetext
specify charset for the source text (unicode) data.
if len(charset) > 0 then
binarystream.charset = charset
else
binarystream.charset = "us-ascii"
end if
open the stream and get binary data from the object
stream_binarytostring = binarystream.readtext
end function
要存储、获取二进制数据，从一个本地文件、上传的二进制数据文件或者asp中，可以参考：pure and huge asp file upload with progress.。 tip keywords: binary, byte, array, vt_ui1, vt_array, binarywrite, binaryread, chrb, instrb, leftb, midb, rightb, asp, vbscopyright and permitted use of http://www.pstruh.cz/tips website. the entire contents of pstruh software website consist of copyright material owned by antonin foller, pstruh software.
