Microsoft KB Archive/177188

= SAMPLE: Using HttpSendRequestEx for Large POST Requests =

Article ID: 177188

Article Last Modified on 8/5/2004

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APPLIES TO


 * Microsoft Internet Explorer 4.01 Service Pack 2
 * Microsoft Internet Explorer 4.0 128-Bit Edition

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This article was previously published under Q177188



SUMMARY
This sample demonstrates proper usage of the HttpSendRequestEx function introduced in the Internet Explorer 4.0 WinInet.dll and documented in the Internet Client SDK.

The original HttpSendRequest function has a significant limitation: all the data for the request has to be provided in a single buffer when the function is called. This is often inconvenient, leads to poor performance in certain client applications, and may make it impossible to upload large amounts of data from client machines with limited memory. The new HttpSendRequestEx function allows a program to start a request, send out the data in small pieces as available, then end the request once all the data has been sent. Internet Explorer 4.0 must be installed on the computer in order for this function to work. The following file is available for download from the Microsoft Download Center:

Hsrex.exe

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:

119591 How to Obtain Microsoft Support Files from Online Services

Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.



MORE INFORMATION
Hsrex.exe is a self-extracting archive that contains BigPost.cpp (the code for the demonstration program) and Readall.asp, an Active Server Pages (ASP) script that will read all data sent in a POST request. Readall.asp is provided as a sample target for BigPost, which can be used on Microsoft Internet Information Server (IIS) versions that support ASP. For other Web servers, you will need to provide a corresponding server script to read the data.

To compile the program with Microsoft Visual C++ 5.0, follow these steps:


 * 1) Run Visual C++ and create a new Win32 Console Application called "BigPost."
 * 2) In the directory where the project was created, run Hsrex.exe.
 * 3) Add BigPost.cpp to the BigPost project.
 * 4) Go to the Project Settings dialog box, click the Link tab, and add WinInet.lib to the "Object/library modules:" field.
 * 5) Ensure that Visual C++ is configured so that the compiler and linker will use the Wininet.h and Wininet.lib from the Internet Client SDK. If this is not done, a compiler or linker error will result. The include and library files included in Visual C++ do not contain the prototype and export of HttpSendRequestEx.
 * 6) Build the project. It will create BigPost.exe.

The program is run as follows:

BigPost   

For example, the following would POST 1 megabyte (1024KB) to http://yourserver/scripts/ReadAll.asp:

BigPost 1024 yourserver /scripts/ReadAll.asp

The output from this would be as follows:   Test of POSTing 1024KB with WinInet 1048576 bytes sent. The following was returned by the server: 1048576 bytes were read.

Finished.