INFO: Guidelines to Use WinHttp, Managed Code APIs (System.Net classes) or WinInet (821876)

SUMMARY

This article describes the differences between Windows HTTP Services (WinHTTP), managed code APIs (System.Net namespace classes), and Windows Internet API (WinINet). (With the release of the February 2003 Software Developer Kit [SDK], the tool formerly abbreviated WinInet is now named WinINet.) This information is designed to help you select the correct technology to use when your application requires Internet or intranet resources. This article does not cover higher level tools such as the SOAP Toolkit, Microsoft XML Core Services (MSXML) objects, Web services proxies in managed code, or client-side Active Template Library (ATL) Server classes such as CAtlHttpClientT and CSoapSocketClientT. When you must have more control than the APIs in this "Summary" section provide, you can use socket APIs.

MORE INFORMATION

Affected components should use WinHTTP. WinHTTP is supported in the context of a system service. Another solution is to use System.Net classes or sockets directly. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
238425 WinInet Not Supported for Use in Services
If yours is a new unmanaged Microsoft Win32-based project in Microsoft C or in Microsoft C++, use WinHTTP or System.Net classes if the functionality that you must have is available through WinHTTP or through System.Net classes (see the table that follows). If you call managed-code APIs from unmanaged code, you can use the managed-code APIs without rewriting them. If your application is a Microsoft Visual Basic 6.0 application, use the WinHttpRequest COM object.
For managed code applications, use the managed code http stack (System.Net.WebRequest classes) if the functionality is available. Note: Other HTTP protocol managed classes are HttpWebRequest\HttpWebResponse and WebClient. For additional information about how to use the classes, click the following article number to view the article in the Microsoft Knowledge Base:
303436 SAMPLE: Visual C# .NET Networking Classes HTTP Internet Client

The following table shows the solutions and operating systems that Microsoft supports, that Microsoft may support in the future, and that Microsoft does not support.

Functionality	System.Net (managed) classes	WinINet APIs	WinHTTP 5.1 (Win32 and COM APIs)
HTTP (client)	Yes.	Yes.	Yes.
Cache	No. Microsoft may add this feature in the future versions.	Yes.	No.
Authentication (Basic, Digest, Negotiate, NTLM)	Yes.	Yes.	Yes.
AutoDial	No. Use remote access APIs.	Yes.	No. Use remote access APIs.
Cookies	No. Session cookies only.	Yes.	No. Session cookies only.
FTP	No. You can implement your own protocol handler for FTP. Microsoft may add FTP in future versions.	Yes.	No.
P3P	No.	Yes.	No.
Proxy: Includes dynamic proxy Web Proxy Auto-Discovery (WPAD)	No. Static proxy only (Microsoft may add dynamic proxy to future versions).	Yes.	Yes.
SSL	Yes.	Yes.	Yes.
Gopher	No.	Yes.	No.
Support Services	Yes.	No.	Yes.
New features	Yes. Microsoft may add new features.	No. Microsoft does not plan to add new features.	Yes. Microsoft may add new HTTP-specific features.
Operating systems supported	Microsoft Windows 98, Microsoft Windows Millennium Edition (Windows Me), Microsoft Windows NT Server 4.0, Microsoft Windows 2000 operating system and Windows 2000 service packs, Microsoft Windows XP operating system and Windows XP service packs, Microsoft Windows Server 2003 and future releases.	Windows 9x, Windows Me, Windows NT Server 4.0, Windows 2000 operating system and Windows 2000 service packs, Windows XP operating system and Windows XP service packs, Windows Server 2003 and future releases.	Windows 2000 with Service Pack 3 and later, Windows XP with Service Pack 1 and later, Windows Server 2003 and future releases.

Note For more information about FTP user samples, visit the following Microsoft Web site: http://www.gotdotnet.com/Community/UserSamples/Default.aspx?query=FTP

REFERENCES

For more information about WinHTTP, visit the following Microsoft Developer Network Web site:

http://msdn.microsoft.com/library/en-us/winhttp/http/portal.asp

For additional information about WinINet, visit the following Microsoft Developer Network Web site:

http://msdn.microsoft.com/library/en-us/wininet/wininet/about_wininet.asp

For additional information about classes available in the Microsoft .NET Framework to access the Internet, visit the following Microsoft Developer Web site:

http://msdn.microsoft.com/library/en-us/cpguide/html/cpconaccessinginternet.asp

For additional information about Windows Sockets APIs, visit the following Microsoft Developer Web site:

http://msdn.microsoft.com/library/en-us/winsock/winsock/windows_sockets_start_page_2.asp