MORE INFORMATION
ActiveX controls are embedded in Web pages using the OBJECT tag. The
CODEBASE attribute of the OBJECT tag specifies the location from which to
download the control. CODEBASE can point to a number of different file
types successfully.
For instance, CODEBASE can point directly to an .ocx file as follows:
CODEBASE="http://example.microsoft.com/somecontrol.ocx#version=4,70,0,1086"
Because this downloads and installs only the .ocx file, this solution
relies on any necessary supporting DLLs already existing on the client
machine. In most cases, it should not be assumed that these DLLs will exist
on the client and be the correct version.
Another alternative is for CODEBASE to point to an .inf file, for example:
CODEBASE="http://example.microsoft.com/doyoutrustme.inf"
An .inf file controls the installation of an .ocx file and its supporting
files. This method is NOT recommended because it is not possible to sign an
.inf file (see the REFERENCES section for references on code signing).
The best solution is for CODEBASE to point to a cabinet file. With this
method, supporting DLLs can be referenced and the cabinet file signed.
NOTE: If the directions below for referencing the MFC DLLs are followed,
the MFC DLLs will not be downloaded if they already exist on the client.
The CODEBASE line will resemble the following:
CODEBASE="http://example.microsoft.com/acontrol.cab#version=1,2,0,0"
Note here that the #Version information applies to the version of the
control specified by the CLASSID parameter of the OBJECT tag.
Cab Packaging Overview
In the Cabinet Software Development Kit (also called Cabinet SDK, or CAB
Development Kit) you will find the necessary tools to construct cabinet
(.cab) files. See the following Microsoft Web site:
The cabinet file that CODEBASE points to should contain the .ocx file and
an .inf file that will control the installation of the ActiveX Control.
Dependent DLLs that may already exist on the system, such as the MFC DLLs,
should not be included in this cabinet file. Instead, the MFC DLLs, and
other dependent DLLs, should be packaged in separate cabinet files and
referenced by the control's .inf file. The following example illustrates
how to package the MFC Spindial sample control.
The OBJECT tag to include the Spindial control in a Web page resembles
the following:
<OBJECT ID="Spindial1" WIDTH=200 HEIGHT=200
CLASSID="CLSID:06889605-B8D0-101A-91F1-00608CEAD5B3"
CODEBASE="http://example.microsoft.com/spindial.cab#Version=1,0,0,001">
<PARAM NAME="_Version" VALUE="65536">
<PARAM NAME="_ExtentX" VALUE="2646">
<PARAM NAME="_ExtentY" VALUE="1323">
<PARAM NAME="_StockProps" VALUE="0">
<PARAM NAME="NeedlePosition" VALUE="2">
</OBJECT>
In this case, Spindial.cab must contain two files, Spindial.ocx and
Spindial.inf. The command to build this cabinet file is similar to the
following depending on the path to your installation of the Cabinet
Development Kit:
C:\CabDevKit\cabarc.exe N spindial.cab spindial.ocx spindial.inf
The following is an example .inf for the MFC Spindial control. This .inf
file can be modified to download any MFC ActiveX Control by changing
Spindial's information to the desired MFC ActiveX Control's information.
See comments below.
; ========================= spindial.inf ========================
; This .inf file will control the installation of the MFC Spindial
; control. This control has been compiled with Visual C++ version 4.2.
; The FileVersion tags in the dependent DLLs section on this file
; reflect this requirement.
[version]
; version signature (same for both NT and Win95) do not remove
signature="$CHICAGO$"
AdvancedINF=2.0
[Add.Code]
spindial.ocx=spindial.ocx
; These are the necessary supporting DLLs for MFC 4.2 ActiveX Controls
mfc42.dll=mfc42.dll
msvcrt.dll=msvcrt.dll
olepro32.dll=olepro32.dll
; thiscab is a keyword which, in this case, means that Spindial.ocx
; can be found in the same .cab file as this .inf file
; file-win32-x86 is an x86 platform specific identifier
; See the ActiveX SDK - ActiveX Controls - Internet Component Download -
; Packaging component code for automatic download
[spindial.ocx]
file-win32-x86=thiscab
; *** add your controls CLSID here ***
clsid={06889605-B8D0-101A-91F1-00608CEAD5B3}
; Add your ocx's file version here.
FileVersion=1,0,0,001
RegisterServer=yes
; dependent DLLs
[msvcrt.dll]
; This is an example of conditional hook. The hook only gets processed
; if msvcrt.dll of the specified version is absent on client machine.
FileVersion=4,20,0,6164
hook=mfc42installer
[mfc42.dll]
FileVersion=4,2,0,6256
hook=mfc42installer
[olepro32.dll]
FileVersion=4,2,0,6068
hook=mfc42installer
[mfc42installer]
file-win32-x86=VALUE=http://activex.microsoft.com/controls/vc/mfc42.cab
; If dependent DLLs are packaged directly into the above cabinet file
; along with an .inf file, specify that .inf file to run as follows:
;InfFile=mfc42.inf
; The mfc42.cab file actually contains a self extracting executable.
; In this case we specify a run= command.
run=%EXTRACT_DIR%\mfc42.exe
; ====================== end of spindial.inf =====================
The following sections of this .inf file will need to be modified depending
on your control and the version of MFC that you are using to build your
control:
- Any reference to spindial should be changed to the name of your control. This includes comments and the following:
spindial.ocx=spindial.ocx
[spindial.ocx]
- The following should be changed to the correct CLSID and FileVersion for your control:
clsid={06889605-B8D0-101A-91F1-00608CEAD5B3}
FileVersion=1,0,0,001
The CLSID above can be obtained for your control from the control's ODL
file. The CLSID is associated with the coclass for the control. For
instance, the above CLSID was obtained from the following section of
Spindial.odl:
[ uuid(06889605-B8D0-101A-91F1-00608CEAD5B3),
helpstring("Spindial Control"), control ]
coclass Spindial
The FileVersion for the control can be obtained from the version resource
for the control. As is true of any file with a version resource, this can
be obtained by opening the file (Spindial.ocx in this case ) version
resource with Visual Studio. From the File menu, select Open, and click Open as: Resources. Open the Version resource; the FileVersion that you are interested in is listed after FILEVERSION. - The last change that you need to make is to enter the correct
FileVersion for each of the MFC DLLs, [mfc42.dll], [olepro32.dll], and
[mscvrt.dll]. Note that if you are using Visual C++ 4.1 or earlier, you need to change any reference to Mfc42.dll to Mfc40.dll and any reference to
Msvcrt.dll to Msvcrt40.dll.
The following FileVersions should be used:
VC 4.1 and earlier, use:
Olepro32.dll 4,1,0,6038
Mfc40.dll 4,1,0,6139
Msvcrt40.dll 4,10,0,6038
VC 4.2b and earlier, use:
Olepro32.dll 4,2,0,6068
Mfc42.dll 4,2,0,6256
Msvcrt.dll 4,20,0,6164
VC 5.0, use:
Olepro32.dll 5,0,4055,1
Mfc42.dll 4,21,0,7022
Msvcrt.dll 5,0,0,7022
VC 5.0sp1, use:
Olepro32.dll 5,0,4055,1
Mfc42.dll 4,21,0,7160
Msvcrt.dll 5,0,0,7128
VC 5.0sp2, use:
Olepro32.dll 5,0,4055,1
Mfc42.dll 4,21,0,7160
Msvcrt.dll 5,0,0,7128
VC 5.0sp3, use:
Olepro32.dll 5,0,4230,1
Mfc42.dll 4,21,0,7303
Msvcrt.dll 5,0,0,7303
VC 6.0, use:
Olepro32.dll 5,0,4261,0
Mfc42.dll 6,0,8168,0
Msvcrt.dll 6,0,8168,0
Notice that all versions of MFC between 4.2 and 6.0 use Mfc42.cab. This
.cab file always contains the latest version of the DLLs because they are
backward-compatible. If you are not compiling with a later build of MFC,
you may not want to specify the latest FileVersion. Doing so may trigger an
unnecessary download of the MFC DLLs.