1 //------------------------------------------------------------------------------
2 // <copyright file="IISVersionHelper.cs" company="Microsoft">
3 //     Copyright (c) Microsoft Corporation.  All rights reserved.
4 // </copyright>
5 //------------------------------------------------------------------------------
6 
7 using System.Runtime.InteropServices;
8 namespace System.Web.Configuration {
9     internal class IISVersionHelper : IDisposable {
10         const int IIS_PRODUCT_EXPRESS = 2;
11 
12         [ComImport, Guid("1B036F99-B240-4116-A6A0-B54EC5B2438E"), InterfaceType((short)1)]
13         interface IIISVersion {
14             [return: MarshalAs(UnmanagedType.Struct)]
GetPropertyValue([In, MarshalAs(UnmanagedType.BStr)] string bstrName)15             object GetPropertyValue([In, MarshalAs(UnmanagedType.BStr)] string bstrName);
16             [return: MarshalAs(UnmanagedType.Struct)]
CreateObjectFromProgId([In, MarshalAs(UnmanagedType.BStr)] string bstrObjectName)17             object CreateObjectFromProgId([In, MarshalAs(UnmanagedType.BStr)] string bstrObjectName);
18             [return: MarshalAs(UnmanagedType.Struct)]
CreateObjectFromClsId([In] Guid clsidObject)19             object CreateObjectFromClsId([In] Guid clsidObject);
ApplyIISEnvironmentVariables()20             void ApplyIISEnvironmentVariables();
ClearIISEnvironmentVariables()21             void ClearIISEnvironmentVariables();
ApplyManifestContext()22             void ApplyManifestContext();
ClearManifestContext()23             void ClearManifestContext();
24         }
25 
26         [ComImport, InterfaceType((short)1), Guid("9CDA0717-2EB5-42b3-B5B0-16F4941B2029")]
27         interface IIISVersionManager {
28             [return: MarshalAs(UnmanagedType.Interface)]
GetVersionObject([In, MarshalAs(UnmanagedType.BStr)] string bstrVersion, [In, MarshalAs(UnmanagedType.I4)] int productType)29             IIISVersion GetVersionObject([In, MarshalAs(UnmanagedType.BStr)] string bstrVersion, [In, MarshalAs(UnmanagedType.I4)] int productType);
30             [return: MarshalAs(UnmanagedType.SafeArray, SafeArraySubType = VarEnum.VT_VARIANT)]
GetAllVersionObjects()31             IIISVersion[] GetAllVersionObjects();
32         }
33 
34         IIISVersionManager _versionManager;
35         IIISVersion _version;
36 
IISVersionHelper(string version)37         internal IISVersionHelper(string version) {
38             // version is null if we're supposed to use the OS's IIS installation
39             if (version == null)
40                 return;
41 
42             try {
43                 _versionManager = CreateVersionManager();
44                 _version = _versionManager.GetVersionObject(version, IIS_PRODUCT_EXPRESS);
45                 _version.ApplyManifestContext();
46             }
47             catch {
48                 Release();
49                 throw;
50             }
51         }
52 
CreateVersionManager()53         private static IIISVersionManager CreateVersionManager() {
54             Type type = Type.GetTypeFromProgID("Microsoft.IIS.VersionManager", throwOnError: true);
55             return (IIISVersionManager)Activator.CreateInstance(type);
56         }
57 
Dispose()58         public void Dispose() {
59             if (_version != null) {
60                 _version.ClearManifestContext();
61                 Release();
62             }
63         }
64 
Release()65         private void Release() {
66             if (_version != null) {
67                 Marshal.ReleaseComObject(_version);
68                 _version = null;
69             }
70             if (_versionManager != null) {
71                 Marshal.ReleaseComObject(_versionManager);
72                 _versionManager = null;
73             }
74         }
75     }
76 }
77