ASP components upload ---------

But use:

This encoding scheme is more efficient than the default "Application / X-URL-Encoded" form encoding scheme in transmitting large amounts of data. The URL encoding is only a limited character set. Use any characters that exceed the character set, must be replaced with '% NN', where NN represents the corresponding 2 hexadecimal numbers. For example, even the ordinary space character is replaced with '% 20'. The RFC1867 uses multiple MIME encodings, just like it is often seen in the E-mail message, not encoding a large amount of data, but only adds little but simple but practical heads around the data. The main browser manufacturers have adopted the recommendation "Browse ..." button, and users can easily use the local "Open File ..." dialog to select the file you want to upload. RFC1867 still leaves the flexible method uploaded by most files to your web application. PUT is used very limited. WebDAV is very useful for the author of content, such as FrontPage users, but Web developers who want to join files in a web application are rarely used. Therefore, RFC1867 is the best way to join file uploads in a web application.

In practical applications, Microsoft offers Posting Acceptor. ASP does not understand the "Multipart / Form-Data" coding scheme. Instead, Microsoft provides Posting Acceptor, Posting Acceptor is an ISAPI application that accepts Repost to an ASP page after the upload is completed.

SA-Fileup of Software Artisans is one of the earliest commercial Active Server components. Several improvements, now exists as a purely ASP component.

two. Principle Analysis of File Uploading Based on ASP

The basic principle is to read all the data in the FORM in the BinaryRead method of the ADO Stream object, and intercept the required file data, and store the binary file.

Below is an example of uploading file pages (UPLOAD.HTM):

The file object is used in the program so that the original data read in the BinaryRead method in UPLOAD.ASP is not only the data of the selected file itself, but also contains the path, type, and submission page on the user's hard disk. The description of related information so that we need to extract the specific content of the file. According to the analysis, the header information of the data and the data of the data is two pairs of carriage return, and the tail also has separated information, we can use the following method to obtain file data.

Dim FormData.FormSize, DataStart, CLStr, DivStrFormSize = Request.TotalBytesFormData = Request.BinaryRead (FormSize) CLStr = ChrB (13) & ChrB (10) DataStart = InStrB (FormData.CLStr & CLStr) 4'4 are two pairs of carriage return linefeed Length divstr = Leftb (FormData, INSTRB (FormData, CLSTR) -1) DataSize = INSTRB (Datastart 1, Formdata, Divstr) -datastart-2formData = MIDB (FormData, Datast, DataSize) Formdata is the content of the file. The intermediate can be processed according to the needs. The final job is to save the file. There are two ways to save: one is to use the binary operation method in the VB or VC program, add the appropriate type library in the project, and finally compile into a DLL file, and then register the DLL file when used. . The file storage program is as follows:

Public Function SaveFile (Pathname As String) As String Dim objContext As ObjectContext Dim objRequest As Request Set objContext = GetObjectContext () Set objRequest = objContext ( "Request") 'the following piece of code is a file stored on the operation Dim FormData () As Byte, cLStr, DivStr Dim DataStart As Long, DataSize As Long DataSize = objRequest.TotalBytes Redim FormData (DataSize-1) FormData = objRequest.BinaryRead (DataSize) cLStr = ChrB (13) & ChrB (10) DataStart = InStrB (FormData , CLSTR & CLSTR) 4 DivStr = Leftb (FormData, INSTRB (Formdata, CLSTR) -1) DataSize = INSTRB (DataStart 1, Formdata, Divstr) -DataStart-2 FormData = MIDB (Formdata, Datast, DataSize) 'creation A binary file and writes Formdata Open Pathname for binary as 1 Put # 1, Formdata Close # 1 Savefile = "OK!" End function

The second method is to complete the binary operation method provided in the ADO stream, the statement to save the file is: streamobj.savetofile (filename, 2). In this operation, we can put the relevant operations in a class file, and it is possible to include this class file directly in the ASP program when applying. For specific processing methods, please refer to the relevant introduction.