Forces a System.Security.SecurityException at run time if all callers higher in the call stack have not been granted the permission specified by the current instance.
Type Reason System.Security.SecurityException
A caller does not have the permission specified by the current instance.
A caller has called CodeAccessPermission.Deny for the resource protected by the current instance.
This method is typically used by secure libraries to ensure that callers have permission to access a resource. For example, a file class in a secure class library calls CodeAccessPermission.Demand for the necessary System.Security.Permissions.FileIOPermission before performing a file operation requested by the caller.
The permissions of the code that calls this method are not examined; the check begins from the immediate caller of that code and proceeds up the stack. The call stack is typically represented as growing down, so that methods higher in the call stack call methods lower in the call stack. CodeAccessPermission.Demand succeeds only if no System.Security.SecurityException is raised.