Using python as a COM client

[mhurwitch at roadnet.com]

I spent some time today learning how to use python as a COM client.
It's pretty straight-forward, but I did have a little bit of a learning
curve when I tried to use secondary dispinterfaces. I am posting here
so that an example is available on Deja News.


I have an ATL object that implements a primary dispinterface as
IMsgBoxObj, and a secondary dispinterface as IMsgBoxObj2. It answers a
query for IDispatch by returning IMsgBoxObj. Here's the IDL :


[
	object,
	uuid(1F17E70E-676E-11D3-AC59-00500462ECB1),
	dual,
	helpstring("IMsgBoxObj Interface"),
	pointer_default(unique)
]
interface IMsgBoxObj : IDispatch
{
	[id(1), helpstring("method ShowMsgBox")] HRESULT ShowMsgBox();
};

[
	object,
	uuid(F2570840-70C3-11d3-AC59-00500462ECB1),
	dual,
	helpstring("IMsgBoxObj2 Interface"),
	pointer_default(unique)
]
interface IMsgBoxObj2 : IDispatch
{
	[id(2), helpstring("method ShowMsgBox2")] HRESULT ShowMsgBox2();
};

[
	uuid(1F17E700-676E-11D3-AC59-00500462ECB1),
	version(1.0),
	helpstring("MsgBoxObject 1.0 Type Library")
]
library MSGBOXOBJECTLib
{
	importlib("stdole32.tlb");
	importlib("stdole2.tlb");

	[
		uuid(1F17E70F-676E-11D3-AC59-00500462ECB1),
		helpstring("MsgBoxObj Class")
	]
	coclass MsgBoxObj
	{
		[default] interface IMsgBoxObj;
		interface IMsgBoxObj2;
	};
};



The following python script can be used to exercise the object :

#--------------------------------------------------------------------
#   multiple dispinterface client

import pythoncom
import win32com.client

#   create a MsgBoxObj, ask it for the object's default dispinterface
#   (by requesting IDispatch), and wrap the interface
#   reference in an object that knows how to a dispinterface

IMsgBoxObj = win32com.client.Dispatch("MsgBoxObject.MsgBoxObj")

IMsgBoxObj.ShowMsgBox()


#   now ask for a different dispinterface on the same object

IID_IMsgBoxObj2 = pythoncom.MakeIID("{F2570840-70C3-11d3-AC59-
00500462ECB1}")

dispinterface2 = IMsgBoxObj._oleobj_.QueryInterface(IID_IMsgBoxObj2,
pythoncom.IID_IDispatch)

IMsgBoxObj2 = win32com.client.Dispatch(dispinterface2,
resultCLSID=IID_IMsgBoxObj2)

IMsgBoxObj2.ShowMsgBox2()

#--------------------------------------------------------------------


Hope this is of some use...









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