CreateOleObject

 System.Win.ComObj.pas

Variant vapp;
vapp = Unassigned;

GUID guid = Comobj::StringToGUID("{F6295C21-BA09-418A-A98B-BAA87B50983E}");
vapp = (IUnknown*) CreateComObject(guid);
vapp.OleFunction("fun1",p1,p2);
v = Unassigned;

CoUninitialize

 CreateOleObject

Unassigned 在单元文件里 varaints

Variant obj = CreateOleObject("mycom.myView");
obj = Unassigned;

CoCreateInstance

http://blog.csdn.net/winglet/article/details/2872342

readydcard
   in_str: string;
  ou_str: string;

 
var   imcom: Variant;
    imcom := CreateOleObject('wwaa.windows.sdk.api');
    
    ou_str := imcom.fun(in_str);
  obj = Unassigned;

c#调用com

 Type oleType = Type.GetTypeFromProgID("MCtestinterface.1.0");
            object oleObject = System.Activator.CreateInstance(oleType);
            oleType.InvokeMember("printreport", BindingFlags.InvokeMethod, null, oleObject, new object[] { hisrequest });
            return 0;

 https://www.cnblogs.com/ShaYeBlog/p/4811297.html