ASP.NET 3.5 For Dummies®

22.6. Head Off a Serious Lack of Trust

Hundreds of companies sell precompiled assemblies to enhance your Web pages, perform calculations, generate documents, and work miracles with .NET. Most vendors provide trial versions to play with before spending your (or your company's) cash. If the component works fine on your development system, check with the vendor on the exact permissions the component requires on the Web server. Specifically, ask whether it runs under Partial Trust.

Web-hosting companies set rules on their systems for ASP.NET and its components. For shared hosting, most companies restrict ASP.NET to running under Partial Trust. In the Partial Trust scenario, Web pages usually aren't allowed to access the Windows Registry or perform file access operations outside the site's directory. If any component that ASP.NET uses requires Full Trust — or depends on something that requires Full Trust — the permissions break down. Workarounds, such as using a virtual server or even a dedicated machine, are more expensive than shared hosting.

NOTE

A component that runs perfectly in the freewheeling Visual Web Developer environment might halt in the restrictive Partial Trust world.