How to interpret HRESULT for Automation Server method call?

IMAGEDISPLAY_TBL.pas
unit ImageDisplay_TLB;
 
// PASTLWTR : 1.2
// File generated on 8/25/2008 12:34:32 PM from Type Library described below.
 
// ************************************************************************  //
// Type Lib: C:\Program Files\Borland\Delphi7\Projects\Display4Automation2\Display4Automation3\ImageDisplay.tlb (1)
// LIBID: {0EB7654F-85A7-4DB1-A9D6-4BC950E298B7}
// LCID: 0
// Helpfile: 
// HelpString: ImageDisplay Library
// DepndLst: 
//   (1) v2.0 stdole, (C:\WINDOWS\system32\stdole2.tlb)
// ************************************************************************ //
{$TYPEDADDRESS OFF} // Unit must be compiled without type-checked pointers. 
{$WARN SYMBOL_PLATFORM OFF}
{$WRITEABLECONST ON}
{$VARPROPSETTER ON}
interface
 
uses Windows, ActiveX, Classes, Graphics, StdVCL, Variants;
  
 
// *********************************************************************//
// GUIDS declared in the TypeLibrary. Following prefixes are used:        
//   Type Libraries     : LIBID_xxxx                                      
//   CoClasses          : CLASS_xxxx                                      
//   DISPInterfaces     : DIID_xxxx                                       
//   Non-DISP interfaces: IID_xxxx                                        
// *********************************************************************//
const
  // TypeLibrary Major and minor versions
  ImageDisplayMajorVersion = 1;
  ImageDisplayMinorVersion = 0;
 
  LIBID_ImageDisplay: TGUID = '{0EB7654F-85A7-4DB1-A9D6-4BC950E298B7}';
 
  IID_IImageDisplayInterface: TGUID = '{E7A22657-E720-4D79-A31F-C232390DB090}';
  DIID_IImageDisplayInterfaceEvents: TGUID = '{A9BD6966-B3C9-42D1-BEFD-549F87868AAA}';
  CLASS_ImageDisplayInterface: TGUID = '{A3087BD2-823D-4361-9970-E5AC0ED4A75F}';
type
 
// *********************************************************************//
// Forward declaration of types defined in TypeLibrary                    
// *********************************************************************//
  IImageDisplayInterface = interface;
  IImageDisplayInterfaceDisp = dispinterface;
  IImageDisplayInterfaceEvents = dispinterface;
 
// *********************************************************************//
// Declaration of CoClasses defined in Type Library                       
// (NOTE: Here we map each CoClass to its Default Interface)              
// *********************************************************************//
  ImageDisplayInterface = IImageDisplayInterface;
 
 
// *********************************************************************//
// Interface: IImageDisplayInterface
// Flags:     (4416) Dual OleAutomation Dispatchable
// GUID:      {E7A22657-E720-4D79-A31F-C232390DB090}
// *********************************************************************//
  IImageDisplayInterface = interface(IDispatch)
    ['{E7A22657-E720-4D79-A31F-C232390DB090}']
    procedure WorkInvoice(company: OleVariant; invType: OleVariant; out docID: OleVariant; 
                          out mStatus: OleVariant); safecall;
    procedure SaveVoucher(docID: OleVariant; docIDSeq: OleVariant; company: OleVariant; 
                          bu: OleVariant; vndrNo: OleVariant; invNo: OleVariant; 
                          invDate: OleVariant; vchrID: OleVariant; po_no: OleVariant; 
                          out mStatus: OleVariant); safecall;
    procedure UnBusyInvoice(docID: OleVariant; out mStatus: OleVariant); safecall;
    procedure GetVndrNameAddr(searchStr: OleVariant; out srchCount: OleVariant; 
                              out vndrNameAddr: OleVariant; out mStatus: OleVariant); safecall;
  end;
 
// *********************************************************************//
// DispIntf:  IImageDisplayInterfaceDisp
// Flags:     (4416) Dual OleAutomation Dispatchable
// GUID:      {E7A22657-E720-4D79-A31F-C232390DB090}
// *********************************************************************//
  IImageDisplayInterfaceDisp = dispinterface
    ['{E7A22657-E720-4D79-A31F-C232390DB090}']
    procedure WorkInvoice(company: OleVariant; invType: OleVariant; out docID: OleVariant; 
                          out mStatus: OleVariant); dispid 201;
    procedure SaveVoucher(docID: OleVariant; docIDSeq: OleVariant; company: OleVariant; 
                          bu: OleVariant; vndrNo: OleVariant; invNo: OleVariant; 
                          invDate: OleVariant; vchrID: OleVariant; po_no: OleVariant; 
                          out mStatus: OleVariant); dispid 202;
    procedure UnBusyInvoice(docID: OleVariant; out mStatus: OleVariant); dispid 203;
    procedure GetVndrNameAddr(searchStr: OleVariant; out srchCount: OleVariant; 
                              out vndrNameAddr: OleVariant; out mStatus: OleVariant); dispid 204;
  end;
 
// *********************************************************************//
// DispIntf:  IImageDisplayInterfaceEvents
// Flags:     (4096) Dispatchable
// GUID:      {A9BD6966-B3C9-42D1-BEFD-549F87868AAA}
// *********************************************************************//
  IImageDisplayInterfaceEvents = dispinterface
    ['{A9BD6966-B3C9-42D1-BEFD-549F87868AAA}']
  end;
 
// *********************************************************************//
// The Class CoImageDisplayInterface provides a Create and CreateRemote method to          
// create instances of the default interface IImageDisplayInterface exposed by              
// the CoClass ImageDisplayInterface. The functions are intended to be used by             
// clients wishing to automate the CoClass objects exposed by the         
// server of this typelibrary.                                            
// *********************************************************************//
  CoImageDisplayInterface = class
    class function Create: IImageDisplayInterface;
    class function CreateRemote(const MachineName: string): IImageDisplayInterface;
  end;
 
implementation
 
uses ComObj;
 
class function CoImageDisplayInterface.Create: IImageDisplayInterface;
begin
  Result := CreateComObject(CLASS_ImageDisplayInterface) as IImageDisplayInterface;
end;
 
class function CoImageDisplayInterface.CreateRemote(const MachineName: string): IImageDisplayInterface;
begin
  Result := CreateRemoteComObject(MachineName, CLASS_ImageDisplayInterface) as IImageDisplayInterface;
end;
 
end.
 
---------------------------------------------
 
ImageDisplayInterface.pas
unit ImageDisplayInterface;
 
{$WARN SYMBOL_PLATFORM OFF}
 
interface
 
uses
  ComObj, ActiveX, AxCtrls, Classes, ImageDisplay_TLB, StdVcl;
 
type
  TImageDisplayInterface = class(TAutoObject, IConnectionPointContainer, IImageDisplayInterface)
  private
    { Private declarations }
    FConnectionPoints: TConnectionPoints;
    FConnectionPoint: TConnectionPoint;
    FEvents: IImageDisplayInterfaceEvents;
    { note: FEvents maintains a *single* event sink. For access to more
      than one event sink, use FConnectionPoint.SinkList, and iterate
      through the list of sinks. }
  public
    procedure Initialize; override;
  protected
    { Protected declarations }
    property ConnectionPoints: TConnectionPoints read FConnectionPoints
      implements IConnectionPointContainer;
    procedure EventSinkChanged(const EventSink: IUnknown); override;
    procedure WorkInvoice(company, invType: OleVariant; out docID,
      methodStatus: OleVariant); safecall;
    procedure SaveVoucher(docID, docIDSeq, company, bu, vndrNo, invNo, invDate,
      vchrID, po_no: OleVariant; out mStatus: OleVariant); safecall;
    procedure UnBusyInvoice(docID: OleVariant; out mStatus: OleVariant);
      safecall;
    procedure GetVndrNameAddr(searchStr: OleVariant; out srchCount,
      vndrNameAddr, mStatus: OleVariant); safecall;
  end;
 
var vCompany, vDoc_id, vInvType, vDocID, vDoc_id_seq : Variant;
var vBU, vVndr_no, vInv_no, vInv_dt, vVchr_id, vPO : Variant;
var vSearchStr, vCount, vVndrNameAddr : Variant;
 
implementation
 
uses ComServ, ufrmImageDisplay;
 
procedure TImageDisplayInterface.EventSinkChanged(const EventSink: IUnknown);
begin
  FEvents := EventSink as IImageDisplayInterfaceEvents;
end;
 
procedure TImageDisplayInterface.Initialize;
begin
  inherited Initialize;
  FConnectionPoints := TConnectionPoints.Create(Self);
  if AutoFactory.EventTypeInfo <> nil then
    FConnectionPoint := FConnectionPoints.CreateConnectionPoint(
      AutoFactory.EventIID, ckSingle, EventConnect)
  else FConnectionPoint := nil;
end;
 
 
procedure TImageDisplayInterface.WorkInvoice(company, invType: OleVariant;
  out docID, methodStatus: OleVariant);
begin
  vCompany := company;
  vInvtype := invType;
  ufrmImageDisplay.WorkInvoice();
  docID := sDocID1;
  methodStatus := sStatus1;
  //hResult := S_OK;
end;
 
//   MORE MORE METHOD CALLS  REMOVED TO SHORTEN THE CODE
 
 
 
initialization
  TAutoObjectFactory.Create(ComServer, TImageDisplayInterface, Class_ImageDisplayInterface,
    ciSingleInstance, tmApartment);
end.

                                  

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42:
43:
44:
45:
46:
47:
48:
49:
50:
51:
52:
53:
54:
55:
56:
57:
58:
59:
60:
61:
62:
63:
64:
65:
66:
67:
68:
69:
70:
71:
72:
73:
74:
75:
76:
77:
78:
79:
80:
81:
82:
83:
84:
85:
86:
87:
88:
89:
90:
91:
92:
93:
94:
95:
96:
97:
98:
99:
100:
101:
102:
103:
104:
105:
106:
107:
108:
109:
110:
111:
112:
113:
114:
115:
116:
117:
118:
119:
120:
121:
122:
123:
124:
125:
126:
127:
128:
129:
130:
131:
132:
133:
134:
135:
136:
137:
138:
139:
140:
141:
142:
143:
144:
145:
146:
147:
148:
149:
150:
151:
152:
153:
154:
155:
156:
157:
158:
159:
160:
161:
162:
163:
164:
165:
166:
167:
168:
169:
170:
171:
172:
173:
174:
175:
176:
177:
178:
179:
180:
181:
182:
183:
184:
185:
186:
187:
188:
189:
190:
191:
192:
193:
194:
195:
196:
197:
198:
199:
200:
201:
202:
203:
204:
205:
206:
207:
208:
209:
210:
211:
212: