using System;
using System.Runtime.InteropServices;
using ComTypes = System.Runtime.InteropServices.ComTypes;
namespace ComUtils
{
public class ComHelper
{
/// <summary>
/// Returns a string value representing the type name of the specified COM object.
/// </summary>
/// <param name="comObj">A COM object the type name of which to return.</param>
/// <returns>A string containing the type name.</returns>
public static string GetTypeName(object comObj)
{
if (comObj == null)
return String.Empty;
if (!Marshal.IsComObject(comObj))
//The specified object is not a COM object
return String.Empty;
IDispatch dispatch = comObj as IDispatch;
if (dispatch == null)
//The specified COM object doesn't support getting type information
return String.Empty;
ComTypes.ITypeInfo typeInfo = null;
try
{
try
{
// obtain the ITypeInfo interface from the object
dispatch.GetTypeInfo(0, 0, out typeInfo);
}
catch (Exception ex)
{
//Cannot get the ITypeInfo interface for the specified COM object
return String.Empty;
}
string typeName = "";
string documentation, helpFile;
int helpContext = -1;
try
{
//retrieves the documentation string for the specified type description
typeInfo.GetDocumentation(-1, out typeName, out documentation,
out helpContext, out helpFile);
}
catch (Exception ex)
{
// Cannot extract ITypeInfo information
return String.Empty;
}
return typeName;
}
catch (Exception ex)
{
// Unexpected error
return String.Empty;
}
finally
{
if (typeInfo != null) Marshal.ReleaseComObject(typeInfo);
}
}
}
/// <summary>
/// Exposes objects, methods and properties to programming tools and other
/// applications that support Automation.
/// </summary>
[ComImport()]
[Guid("00020400-0000-0000-C000-000000000046")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
interface IDispatch
{
[PreserveSig]
int GetTypeInfoCount(out int Count);
[PreserveSig]
int GetTypeInfo(
[MarshalAs(UnmanagedType.U4)] int iTInfo,
[MarshalAs(UnmanagedType.U4)] int lcid,
out ComTypes.ITypeInfo typeInfo);
[PreserveSig]
int GetIDsOfNames(
ref Guid riid,
[MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.LPWStr)]
string[] rgsNames,
int cNames,
int lcid,
[MarshalAs(UnmanagedType.LPArray)] int[] rgDispId);
[PreserveSig]
int Invoke(
int dispIdMember,
ref Guid riid,
uint lcid,
ushort wFlags,
ref ComTypes.DISPPARAMS pDispParams,
out object pVarResult,
ref ComTypes.EXCEPINFO pExcepInfo,
IntPtr[] pArgErr);
}
}