FIX: The bool Type Does Not Marshal Correctly from Unmanaged Code to Managed Code

When you call unmanaged code that returns a bool type value of false from managed code, the return value may appear as true.

In some cases, the native bool type does not marshal correctly from unmanaged code to managed code.

There are two ways to work around this issue:

• Change existing native DLLs to use BOOL return types instead of bool.
• Use DllImport and the platform invoke services to call to the unmanaged DLL.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that this article describes. Apply it only to systems that are experiencing this specific problem.

Note You must have a Visual Studio license agreement to obtain this hotfix.

To resolve this problem, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.