找出这些东西的一种方法是使用该工具（您可以在此处OleView从 Microsoft 下载）。此工具允许您查看 COM 类型库。类型库（假设 COM 组件的供应商提供了类型库信息）包含有关接口以及应用程序或库公开的 COM 类的方法和属性的信息。
例如，在我的机器上，我可以查看类型库C:\Program Files\Microsoft Office\Office12\EXCEL.EXE并查看 Excel 公开了哪些 COM 对象，以及它们的属性和方法。OleView以 IDL（接口描述语言）显示信息，它或多或少是一个带有额外属性的 C 函数原型）。
这是我OleView用于该__Worksheet.Pictures属性的 IDL 声明：
[id(0x00000303), hidden, helpcontext(0x00010303)]
HRESULT Pictures(
[in, optional] VARIANT Index,
[in, lcid] long lcid,
[out, retval] IDispatch** RHS);
注意hidden声明中的属性。这意味着它不会被大多数 IDE 显示（并且是一个很好的提示，不要依赖始终存在的这种方法 - Microsoft 可以在更高版本的 Excel 中将其删除）。
现在Pictures上课呢？这是完整的 IDL：
[
uuid(000208A7-0000-0000-C000-000000000046),
helpcontext(0x00020067),
hidden
]
dispinterface Pictures {
properties:
methods:
[id(0x60000000), restricted]
void QueryInterface(
[in] GUID* riid,
[out] void** ppvObj);
[id(0x60000001), restricted]
unsigned long AddRef();
[id(0x60000002), restricted]
unsigned long Release();
[id(0x60010000), restricted]
void GetTypeInfoCount([out] unsigned int* pctinfo);
[id(0x60010001), restricted]
void GetTypeInfo(
[in] unsigned int itinfo,
[in] unsigned long lcid,
[out] void** pptinfo);
[id(0x60010002), restricted]
void GetIDsOfNames(
[in] GUID* riid,
[in] char** rgszNames,
[in] unsigned int cNames,
[in] unsigned long lcid,
[out] long* rgdispid);
[id(0x60010003), restricted]
void Invoke(
[in] long dispidMember,
[in] GUID* riid,
[in] unsigned long lcid,
[in] unsigned short wFlags,
[in] DISPPARAMS* pdispparams,
[out] VARIANT* pvarResult,
[out] EXCEPINFO* pexcepinfo,
[out] unsigned int* puArgErr);
[id(0x00000094), propget, helpcontext(0x00010094)]
Application* Application();
[id(0x00000095), propget, helpcontext(0x00010095)]
XlCreator Creator();
[id(0x00000096), propget, helpcontext(0x00010096)]
IDispatch* Parent();
[id(0x00010003), restricted, hidden]
void _Dummy3();
[id(0x0000025a), helpcontext(0x0001025a)]
VARIANT BringToFront();
[id(0x00000227), helpcontext(0x00010227)]
VARIANT Copy();
[id(0x000000d5), helpcontext(0x000100d5)]
VARIANT CopyPicture(
[in, optional, defaultvalue(2)] XlPictureAppearance Appearance,
[in, optional, defaultvalue(-4147)] XlCopyPictureFormat Format);
[id(0x00000235), helpcontext(0x00010235)]
VARIANT Cut();
[id(0x00000075), helpcontext(0x00010075)]
VARIANT Delete();
[id(0x0000040f), helpcontext(0x0001040f)]
IDispatch* Duplicate();
[id(0x00000258), propget, helpcontext(0x00010258)]
VARIANT_BOOL Enabled();
[id(0x00000258), propput, helpcontext(0x00010258)]
void Enabled([in] VARIANT_BOOL rhs);
[id(0x0000007b), propget, helpcontext(0x0001007b)]
double Height();
[id(0x0000007b), propput, helpcontext(0x0001007b)]
void Height([in] double rhs);
[id(0x0001000c), restricted, hidden]
void _Dummy12();
[id(0x0000007f), propget, helpcontext(0x0001007f)]
double Left();
[id(0x0000007f), propput, helpcontext(0x0001007f)]
void Left([in] double rhs);
[id(0x0000010d), propget, helpcontext(0x0001010d)]
VARIANT_BOOL Locked();
[id(0x0000010d), propput, helpcontext(0x0001010d)]
void Locked([in] VARIANT_BOOL rhs);
[id(0x0001000f), restricted, hidden]
void _Dummy15();
[id(0x00000254), propget, hidden, helpcontext(0x00010254)]
BSTR OnAction();
[id(0x00000254), propput, hidden, helpcontext(0x00010254)]
void OnAction([in] BSTR rhs);
[id(0x00000269), propget, helpcontext(0x00010269)]
VARIANT Placement();
[id(0x00000269), propput, helpcontext(0x00010269)]
void Placement([in] VARIANT rhs);
[id(0x0000026a), propget, helpcontext(0x0001026a)]
VARIANT_BOOL PrintObject();
[id(0x0000026a), propput, helpcontext(0x0001026a)]
void PrintObject([in] VARIANT_BOOL rhs);
[id(0x000000eb), helpcontext(0x000100eb)]
VARIANT Select([in, optional] VARIANT Replace);
[id(0x0000025d), helpcontext(0x0001025d)]
VARIANT SendToBack();
[id(0x0000007e), propget, helpcontext(0x0001007e)]
double Top();
[id(0x0000007e), propput, helpcontext(0x0001007e)]
void Top([in] double rhs);
[id(0x00010016), restricted, hidden]
void _Dummy22();
[id(0x0000022e), propget, helpcontext(0x0001022e)]
VARIANT_BOOL Visible();
[id(0x0000022e), propput, helpcontext(0x0001022e)]
void Visible([in] VARIANT_BOOL rhs);
[id(0x0000007a), propget, helpcontext(0x0001007a)]
double Width();
[id(0x0000007a), propput, helpcontext(0x0001007a)]
void Width([in] double rhs);
[id(0x0000026e), propget, helpcontext(0x0001026e)]
long ZOrder();
[id(0x000005f8), propget, helpcontext(0x000105f8)]
ShapeRange* ShapeRange();
[id(0x00000080), propget, helpcontext(0x00010080)]
Border* Border();
[id(0x00000081), propget, helpcontext(0x00010081)]
Interior* Interior();
[id(0x00000067), propget, helpcontext(0x00010067)]
VARIANT_BOOL Shadow();
[id(0x00000067), propput, helpcontext(0x00010067)]
void Shadow([in] VARIANT_BOOL rhs);
[id(0x00000105), propget, helpcontext(0x00010105)]
BSTR Formula();
[id(0x00000105), propput, helpcontext(0x00010105)]
void Formula([in] BSTR rhs);
[id(0x000000b5), helpcontext(0x000100b5)]
Picture* Add(
[in] double Left,
[in] double Top,
[in] double Width,
[in] double Height);
[id(0x00000076), propget, helpcontext(0x00010076)]
long Count();
[id(0x0000002e), helpcontext(0x0001002e)]
GroupObject* Group();
[id(0x000000fc), helpcontext(0x000100fc)]
Picture* Insert(
[in] BSTR Filename,
[in, optional] VARIANT Converter);
[id(0x000000aa), helpcontext(0x000100aa)]
IDispatch* Item([in] VARIANT Index);
[id(0xfffffffc), helpcontext(0x0000fffc)]
IUnknown* _NewEnum();
[id(0x000000d3), helpcontext(0x000100d3)]
Picture* Paste([in, optional] VARIANT Link);
由此，您可以推测该Pictures接口具有一个Cut和Delete方法，以及一个Item属性等。但是，请注意，此界面也标记为hidden，这（再次）很好地表明您不应该真正使用它（是的，我知道您忽略了该警告，但我赞同 Mitch Wheat 的评论，即这通常是一个坏主意使用隐藏类，因为它们通常是供应用程序内部使用的，如有更改，恕不另行通知。）