| Description | DBAppMon notifies a Visual Basic program every time an application or a DLL starts or exits. It also contains properties for retrieving various information about active tasks and modules as well as file version info. |
| File Name | DBAPPMON.VBX |
| Object Type | DBAppMon |
| Remarks | DBAppMon is a VB interface to the libraries TOOLHELP.DLL and VER.DLL. By installing a Toolhelp notification callback, DBAppMon is able to supply a VB program with information regarding application and module startup and termination. The primary reason DBAppMon was written was the need to wait for an application and all its children to terminate. In the process, most of WPS' (a program supplied with the CDK) functionality was included. |
| By being a little creative and combining DBAppMon's features with more standard API calls like GetWindow and GetWindowInstance, it's possible find out a whole lot about the currently running applications. Ever wanted to use the VB AppActivate command, but found that the application in question changes its caption on the fly? DBAppMon is your rescue! | |
| About | This control was developed by Dan Byström. For more information, contact me at e-mail: "dan.bystrom@visual-design.se" or phone: +46 708 68 65 78 (no support calls, please). I would be happy to discuss development of customized VBX'es or OCX'es for you. |
| Distribution | You have the right to do whatever you want with DBAppMon, as long as you don't attempt to modify any of its code. "Do whatever you want" includes using DBAppMon in your own commercial applications and distributing it for free. |
| When the control is loaded in design mode a message is sometimes displayed. This message may not be removed or changed in any way. Anyway, the message won't ever appear at run-time. | |
| I'm giving DBAppMon away for free. If you should decide to use it in an application of yours, this means that I have saved you a whole lot of trouble, time and $$$ doing it yourself. Therefore I think a nice gesture would be to include some sort of credit in your application's about box and/or documentation. You could include the name of the VBX, my name and my e-mail address. I would be glad if you did this. Anyway - happy VB programming with DBAppMon! |
| Revision | Jan 95: | Beta release. |
| history | v0.9: | New property added: MyTask. |
| v1.0: | More resistant to crashing applications. | |
| The Monitor property doesn't show up in design mode. It never should. | ||
| v1.1: | Version info had problem with different language versions. | |
| v1.2: | New property added: HotKey. | |
| New event added: HotKey. |
Properties
| *AllModules | *AllTasks | *HotKey | Index |
| *ModuleFileName | *ModuleFindName | *ModuleLookupName | *ModuleName |
| *ModuleUsage | *Monitor | *MyTask | Name |
| Parent | Tag | *TaskFileName | *TaskInstance |
| *TaskModule | *TaskName | *TaskParent | *VerLanguageName |
| *VerLanguages | *VerQueryValue | *VerReadInfo |
* = The property applies only to DBAppMon.
Events
| *DLLExit | *DLLStart | *AppExit | *AppStart |
| *HotKey |
* = The event applies only to DBAppMon.
AllModules Property
Description
Retrieves all currrently active modules in the system.
Usage
DBAppMon.AllModules
Remarks
The property returns all module handles in a comma separated string.
Data Type
String
AllTasks Property
Description
Retrieves all currrently active tasks in the system.
Usage
DBAppMon.AllTasks
Remarks
The property returns all task handles in a comma separated string.
Data Type
String
HotKey Property
Description
The HotKey property array maintains a list of up to 10 hotkey combinations.
Each hotkey will fire the HotKey event when the keyboard combination gets
pressed, regardless of what application is currently active (as long as
it's not a 32-bit application).
Usage
DBAppMon.HotKey( Index ) [ = KeyCode%
]
Remarks
The key code value should be calculated like this: take the virtual
key code (like in the VB KeyDown event) and then add a combination
of the following constants:
&H0100& shift key pressed simultaneously
&H0200& ctrl key pressed simultaneously
&H0400& alt key pressed simultaneously
&H0800& don't pass the key combination to the active application
Data Type
Integer
ModuleFileName Property
Description
Retrieves the file name from a module handle.
Usage
DBAppMon.ModuleFileName( hModule )
Data Type
String
ModuleFindName Property
Description
Retrieves the module handle of a module name. The module name used
for the search is the content of the property ModuleLookupName.
Usage
DBAppMon.ModuleFindName
Data Type
Integer
ModuleLookupName Property
Description
Gets or sets the module name used in subsequent calls to ModuleFindName.
No action is performed until ModuleFindName is called.
Usage
DBAppMon.ModuleLookupName = [ modulename$
]
Data Type
String
ModuleName Property
Description
Retrieves the module name from a module handle.
Usage
DBAppMon.ModuleName( hModule )
Data Type
String
ModuleUsage Property
Description
Retrieves a module's usage count from a module handle.
Usage
DBAppMon.ModuleUsage( hModule )
Data Type
Integer
Monitor Property
Description
Starts or stops the notification events (DLLStart, DLLExit,
AppStart and AppExit). Note that these events won't be fired
for 32-bit applications.
Usage
DBAppMon.Monitor = [ setting% ]
Data Type
Integer (Boolean)
MyTask Property
Description
Retrieves the task handle of the application itself.
Usage
DBAppMon.MyTask
Remarks
This property just calls the API function GetCurrentTask().
Data Type
Integer
TaskFileName Property
Description
Retrieves the file name from a task handle.
Usage
DBAppMon.TaskFileName( hModule )
Data Type
String
TaskInstance Property
Description
Retrieves the task instance handle from a task handle.
Usage
DBAppMon.TaskInstance( hModule )
Remarks
This is the same handle as returned by the VB Shell function.
Data Type
Integer
TaskModule Property
Description
Retrieves the module handle from a task handle.
Usage
DBAppMon.TaskModule( hModule )
Data Type
Integer
TaskName Property
Description
Retrieves the task name from a task handle.
Usage
DBAppMon.TaskName( hModule )
Data Type
String
TaskParent Property
Description
Retrieves the task's parent from a task handle.
Usage
DBAppMon.TaskParent( hModule )
Remarks
This is the task handle of the application which launched the task.
Data Type
Integer
VerLanguageName Property
Description
Retrieves a language name of version info from a file. A file may
contain multiple languages.
Usage
DBAppMon.VerLanguageName ( Language% )
Remarks
Legal language numbers range from zero to VerLanguages-1.
After reading this property, Language% becomes the current language
used when retrieving version fields with VerQueryValue. This property
retrieves a string in the format "LLLLCCCC Language name", where
the first 4 characters consists of the language code number in hex, characters
5 to 8 are the code page number in hex, character 9 is always a space and
the remaining characters, starting at the 10th position, are the language
name in readable text.
Data Type
String
VerLanguages Property
Description
Retrieves the number of languages the version info is available
in.
Usage
DBAppMon.VerLanguages
Remarks
After version info has been read from a file into memory, this
propery contains the number of languages the versio info is available in.
Data Type
Integer
VerQueryValue Property
Description
Retrieves selected version information previously read into memory
with the VerReadInfo property.
Usage
DBAppMon.VerQueryValue = filedname$
DBAppMon.VerQueryValue
Remarks
This property serves double duty. When written, it stores the name
of a version field, and when read, it fetches the value of that particular
field. Some common field names are: "Comments", "CompanyName",
"FileDescription", "FileVersion", "InternalName",
"LegalCopyright", "LegalTrademarks", "OriginalFilename",
"PrivateBuild", "ProductName", "ProductVersion",
and "SpecialBuild". Note: If the version info is available in
multiple languages, the language last read through the VerLanguageName
property is used.
Data Type
String
Example
DBAppMon1.VerReadInfo = "c:\windows\system\dbappmon.vbx"
DBAppMon1.VerQueryValue = "CompanyName"
MsgBox DBAppMon1.VerQueryValue
DBAppMon1.VerReadInfo = ""
VerReadInfo Property
Description
Retrieves version info from a file.
Usage
DBAppMon.VerReadInfo = filename$
Remarks
The version info is read into memory and kept there for further
investigation through the VerQueryValue property. If the file doesn't
exist or if it doesn't contain verion info, a trappable error 52 (Bad file
name or number) is generated. To free the few bytes used to hold the version
info, set this property to an empty string.
Data Type
String
DLLExit Event
Description
Occurs after a DLL has been unloaded.
Sub DBAppMon_DLLExit ( hModule As Integer)
Remarks
Since the event occurs after the DLL has unloaded, hModule
has is invalid. It shall only be used to be compared with previously stored
hModules.
DLLStart Event
Description
Occurs after a DLL has been loaded.
Sub DBAppMon_DLLStart ( hModule As Integer)
Remarks
hModule may be stored for later use or passed to any of
the ModuleFileName, ModuleName or ModuleUsage properties.
AppExit Event
Description
Occurs after an application has terminated.
Sub DBAppMon_AppExit ( hTask As Integer, nExitCode As Integer)
Remarks
Since the event occurs after the application has terminated,
hTask is invalid. It shall only be used to be compared with previously
stored hTasks. nExitCode contains the application's exit code (ErrorLevel
for DOS applications).
AppStart Event
Description
Occurs after an application has started.
Sub DBAppMon_AppStart ( hTask As Integer)
Remarks
hTask may be stored for later use or passed to any of the
TaskFileName, TaskInstance, TaskModule, TaskName
or TaskParent properties.
HotKey Event
Description
Occurs when a hot key combination, specified with the HotKey
property, has been pressed.
Sub DBAppMon_HotKey ( KeyCode As Integer, KeyInfo As Integer )
Remarks
KeyCode is the same key code as previously passed to the
HotKey property and KeyInfo may be interpreted like this:
bit 0-7: keyboard scan code
bit 8: extended key
bit 9-10: not used
bit 11-12: used internally by Windows
bit 13: context code
bit 14: previous key state
bit 15: key transition state
Version control
The following code shows an easy way to check the version
of DBAPPMON.VBX before it is accessed by VB. In a global module, put the
following declaration:
Declare Function DBAppMonVersion Lib "dbappmon.vbx" ()
As Integer
Then use a Sub Main() as your program's entry point:
Sub Main()
If DBAppMonVersion() < &H120& Then
MsgBox "Your DBAAPPMON.VBX is too old
for this program!", 16
End
End If
'Load your main form here
End Sub