Remove CoClass usages from System.Windows.Forms

src/System.Windows.Forms/src/System/Windows/Forms/FolderBrowserDialog.cs

@@ -25,6 +25,9 @@ namespace System.Windows.Forms
     [SRDescription(nameof(SR.DescriptionFolderBrowserDialog))]
     public sealed class FolderBrowserDialog : CommonDialog
     {
+        private static readonly Guid IID_IFileOpenDialog = new Guid("d57c7288-d4ad-4768-be02-9d969532d960");
+        private static readonly Guid CLSID_FileOpenDialog = new Guid("DC1C5A9C-E88A-4dde-A5A1-60F82A20AEF7");
+
         // Root node of the tree view.
         private Environment.SpecialFolder _rootFolder;
 
@@ -205,12 +208,23 @@ protected override bool RunDialog(IntPtr hWndOwner)
 
         private bool TryRunDialogVista(IntPtr owner, out bool returnValue)
         {
-            OpenFileDialog.NativeFileOpenDialog dialog;
+            IFileOpenDialog dialog;
             try
             {
                 // Creating the Vista dialog can fail on Windows Server Core, even if the
                 // Server Core App Compatibility FOD is installed.
-                dialog = new OpenFileDialog.NativeFileOpenDialog();
+                HRESULT hr = Ole32.CoCreateInstance(
+                    ref CLSID_FileOpenDialog,
+                    IntPtr.Zero,
+                    Ole32.CLSCTX.INPROC_SERVER | Ole32.CLSCTX.LOCAL_SERVER | Ole32.CLSCTX.REMOTE_SERVER,
+                    ref IID_IFileOpenDialog,
+                    out object obj);
+                if (!hr.Succeeded())
+                {
+                    Marshal.ThrowExceptionForHR((int)hr);
+                }
+
+                dialog = (IFileOpenDialog)obj;
             }
             catch (COMException)
             {

src/System.Windows.Forms/src/System/Windows/Forms/OpenFileDialog.cs

@@ -6,6 +6,7 @@
 
 using System.ComponentModel;
 using System.IO;
+using System.Runtime.InteropServices;
 using static Interop;
 using static Interop.Shell32;
 
@@ -19,6 +20,9 @@ namespace System.Windows.Forms
     [SRDescription(nameof(SR.DescriptionOpenFileDialog))]
     public sealed partial class OpenFileDialog : FileDialog
     {
+        private static readonly Guid IID_IFileOpenDialog = new Guid("d57c7288-d4ad-4768-be02-9d969532d960");
+        private static readonly Guid CLSID_FileOpenDialog = new Guid("DC1C5A9C-E88A-4dde-A5A1-60F82A20AEF7");
+
         /// <summary>
         ///  Gets or sets a value indicating whether the dialog box displays a
         ///  warning if the user specifies a file name that does not exist.
@@ -139,7 +143,21 @@ private protected override string[] ProcessVistaFiles(IFileDialog dialog)
             }
         }
 
-        private protected override IFileDialog CreateVistaDialog() => new NativeFileOpenDialog();
+        private protected override IFileDialog CreateVistaDialog()
+        {
+            HRESULT hr = Ole32.CoCreateInstance(
+                ref CLSID_FileOpenDialog,
+                IntPtr.Zero,
+                Ole32.CLSCTX.INPROC_SERVER | Ole32.CLSCTX.LOCAL_SERVER | Ole32.CLSCTX.REMOTE_SERVER,
+                ref IID_IFileOpenDialog,
+                out object obj);
+            if (!hr.Succeeded())
+            {
+                Marshal.ThrowExceptionForHR((int)hr);
+            }
+
+            return (IFileOpenDialog)obj;
+        }
 
         [Browsable(false)]
         [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]

src/System.Windows.Forms/src/System/Windows/Forms/SaveFileDialog.cs

@@ -6,6 +6,7 @@
 
 using System.ComponentModel;
 using System.IO;
+using System.Runtime.InteropServices;
 using static Interop;
 using static Interop.Shell32;
 
@@ -22,6 +23,9 @@ namespace System.Windows.Forms
     ]
     public sealed partial class SaveFileDialog : FileDialog
     {
+        private static readonly Guid IID_IFileSaveDialog = new Guid("84bccd23-5fde-4cdb-aea4-af64b83d78ab");
+        private static readonly Guid CLSID_FileSaveDialogCoClass = new Guid("C0B4E2F3-BA21-4773-8DBA-335EC946EB8B");
+
         /// <summary>
         ///  Gets or sets a value indicating whether the dialog box prompts the user for
         ///  permission to create a file if the user specifies a file that does not exist.
@@ -151,6 +155,20 @@ private protected override string[] ProcessVistaFiles(IFileDialog dialog)
             return new string[] { GetFilePathFromShellItem(item) };
         }
 
-        private protected override IFileDialog CreateVistaDialog() => new NativeFileSaveDialog();
+        private protected override IFileDialog CreateVistaDialog()
+        {
+            HRESULT hr = Ole32.CoCreateInstance(
+                ref CLSID_FileSaveDialogCoClass,
+                IntPtr.Zero,
+                Ole32.CLSCTX.INPROC_SERVER | Ole32.CLSCTX.LOCAL_SERVER | Ole32.CLSCTX.REMOTE_SERVER,
+                ref IID_IFileSaveDialog,
+                out object obj);
+            if (!hr.Succeeded())
+            {
+                Marshal.ThrowExceptionForHR((int)hr);
+            }
+
+            return (IFileSaveDialog)obj;
+        }
     }
 }