vb system programming in practice

8/14/2019 VB System Programming in Practice

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VB system programming inVB system programming in

PracticePractice

ByBy

Gouri VGouri V


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Introduction to APIIntroduction to API

VB - A Serious windows developmentVB - A Serious windows developmenttooltool

What are Windows APIs?What are Windows APIs?Simple VB API ExampleSimple VB API ExampleStatic and Dynamic linkingStatic and Dynamic linking

What is a DLL?What is a DLL?


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API declaration and syntax-API declaration and syntax-

[Public | Private] Declare Sub|Function[Public | Private] Declare Sub|Functionname Lib libname Alias aliasname]name Lib libname Alias aliasname][([arglist])] [As type][([arglist])] [As type]

Ex.Ex.

Public Declare Function GetTickCount _Public Declare Function GetTickCount _Lib "kernel32.dll" () As LongLib "kernel32.dll" () As Long

Where does system locates a DLL?Where does system locates a DLL?

DLL disadvantagesDLL disadvantages Right choice A design issue in analysisRight choice A design issue in analysis

phase.phase.


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Some classic fundas to followSome classic fundas to follow

using APIusing API Using the Any keywordUsing the Any keyword

Declare Sub CopyMemory Lib kernel32 _Declare Sub CopyMemory Lib kernel32 _

Alias RtlMoveMemory (lpvDest As Any, _Alias RtlMoveMemory (lpvDest As Any, _lpvSource As any, ByVal cbCopy As Long)lpvSource As any, ByVal cbCopy As Long)

UDTs and API callsUDTs and API callsPrivate Declare Sub GlobalMemoryStatus _Private Declare Sub GlobalMemoryStatus _

Lib "kernel32" (lpBuffer As MEMORYSTATUS)Lib "kernel32" (lpBuffer As MEMORYSTATUS)

Currency VariablesCurrency Variables Window HandlesWindow Handles Boolean Return ValuesBoolean Return Values Limitations of VB to use WIN32 APIsLimitations of VB to use WIN32 APIs


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Exploring WIN32 APIExploring WIN32 API

Lets begin to exploreLets begin to explore Kernel32.dll, user32.dll, gdi32.dllKernel32.dll, user32.dll, gdi32.dll Kernel32 overviewKernel32 overview

Memory managementMemory management MultithreadingMultithreading File operationsFile operations Process controlProcess control

Kill running Spyware by Process controlKill running Spyware by Process control CreateToolhelp32Snapshot - Takes a snapshot of theCreateToolhelp32Snapshot - Takes a snapshot of the

processes and the heaps, modules, and threads used by theprocesses and the heaps, modules, and threads used by theprocesses; returns handle to snapshot.processes; returns handle to snapshot. Process32First - Retrieves information about the first processProcess32First - Retrieves information about the first process

encountered in a system snapshot.encountered in a system snapshot. Process32Next - Retrieves information about the next processProcess32Next - Retrieves information about the next process

recorded in a system snapshot.recorded in a system snapshot.


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Test Previous instance of Appliaction byTest Previous instance of Appliaction byCreateMutexCreateMutex

Public Declare Function CreateMutex _Public Declare Function CreateMutex _

Lib "kernel32.dll" _Lib "kernel32.dll" _

Alias "CreateMutexA" (lpMutexAttributes As Any, _Alias "CreateMutexA" (lpMutexAttributes As Any, _

ByVal bInitialOwner As Boolean, _ByVal bInitialOwner As Boolean, _

ByVal lpName As String) As LongByVal lpName As String) As Long

Save, save and save your work often!Save, save and save your work often!


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User32 Calls and Gdi32 CallsUser32 Calls and Gdi32 Calls

User32.dll is primarily responsible for, but notUser32.dll is primarily responsible for, but notlimited to:limited to: Windows ManagementWindows Management MenusMenus ControlsControls

Win32 HandlesWin32 Handles

Gdi32.dll call are primarily responsible for, butGdi32.dll call are primarily responsible for, butnot limited to, graphical manipulations.not limited to, graphical manipulations. Windows MessagesWindows Messages SubclassingSubclassing


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More interesting about windowsMore interesting about windows

messagesmessages

WindowWindowProceduresProcedures

Window ClassesWindow Classes Queued MessagesQueued Messages Message LoopsMessage Loops

Nonqueued MessagesNonqueued Messages


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Real time system utilities andReal time system utilities and

challengeschallenges Remove invalid file extensionsRemove invalid file extensions Find out and remove Spywares on your PCFind out and remove Spywares on your PC Make your PC junk freeMake your PC junk free Remove missing softwaresRemove missing softwares Delete malicious startup entriesDelete malicious startup entries Scanning cookiesScanning cookies


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Thanks!!Thanks!!

vb system programming in practice

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