sdk/samples/all in on code/Visual Studio 2008/ManagedAggregator/ManagedAggregator.cs

   1 using System;
   2 using System.Collections.Generic;
   3 using System.Text;
   4 using System.Runtime.InteropServices;
   5 using System.Runtime.Remoting;
   6
   7 namespace ManagedHelpers
   8 {
   9     // This interface will be implemented by the outer object in the
  10     // aggregation - that is, by the shim.
  11     [ComImport]
  12     [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
  13     [Guid("7B70C487-B741-4973-B915-B812A91BDF63")]
  14     internal interface IComAggregator
  15     {
  16         void SetInnerPointer(IntPtr pUnkInner);
  17     }
  18
  19     // This interface is implemented by the managed aggregator - the single
  20     // method is a wrapper around Marshal.CreateAggregatedObject, which can be
  21     // called from unmanaged code (that is, called from the shim).
  22     [ComImport]
  23     [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
  24     [Guid("142A261B-1550-4849-B109-715AA4629A14")]
  25     internal interface IManagedAggregator
  26     {
  27         void CreateAggregatedInstance(
  28             string assemblyName, string typeName, IComAggregator outerObject);
  29     }
  30
  31     // The unmanaged shim will instantiate this object in order to call
  32     // through to Marshal.CreateAggregatedObject.
  33     [ClassInterface(ClassInterfaceType.None)]
  34     [ProgId("ManagedHelpers.ManagedAggregator")]
  35     internal class ManagedAggregator : IManagedAggregator
  36     {
  37         public void CreateAggregatedInstance(
  38             string assemblyName, string typeName, IComAggregator outerObject)
  39         {
  40             IntPtr pOuter = IntPtr.Zero;
  41             IntPtr pInner = IntPtr.Zero;
  42
  43             try
  44             {
  45                 // We use Marshal.CreateAggregatedObject to create a CCW where
  46                 // the inner object (the target managed add-in) is aggregated
  47                 // with the supplied outer object (the shim).
  48                 pOuter = Marshal.GetIUnknownForObject(outerObject);
  49                 object innerObject =
  50                     AppDomain.CurrentDomain.CreateInstanceAndUnwrap(
  51                     assemblyName, typeName);
  52                 pInner = Marshal.CreateAggregatedObject(pOuter, innerObject);
  53
  54                 // Make sure the shim has a pointer to the add-in.
  55                 outerObject.SetInnerPointer(pInner);
  56             }
  57             finally
  58             {
  59                 if (pOuter != IntPtr.Zero)
  60                 {
  61                     Marshal.Release(pOuter);
  62                 }
  63                 if (pInner != IntPtr.Zero)
  64                 {
  65                     Marshal.Release(pInner);
  66                 }
  67             }
  68         }
  69     }
  70
  71 }