ADVANCED VISUAL BASIC 6 in Java

Draw PDF-417 2d barcode in Java ADVANCED VISUAL BASIC 6
ADVANCED VISUAL BASIC 6
PDF 417 Creation In Java
Using Barcode creator for Java Control to generate, create PDF 417 image in Java applications.
pointer points to an array of functions, all of which move the function's offset to a CPU register, then jump to a central routine The central routine replaces the this pointer on the stack with the m_punklnner pointer, looks up the real function pointer in the m_punklnner vtable (based on the passed register value), then jumps to the real function To see this in action, let's look at the CPU registers for the blind delegation of function number 40 Because this is shown in Intel assembly, ESP is the current stack pointer, and ECX passes the function offset The stack looks like: ESP ESP+4 ESP+8 ESP+12 etc ;Return address (jump back here upon completion)) ;The this pointer (points to the blind delegator structure) ;The first parameter ;The second parameter
Barcode Encoder In Java
Using Barcode creator for Java Control to generate, create barcode image in Java applications.
Pseudocode:
Barcode Scanner In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
ECX = 40 Jump to main function ESP+4 = m_punkInner from blind delegator structure Jump to the correct function in the real vtable, calculated with (*m_punkInner) [ECX] Note here that the parameters are completely untouched Only the this pointer is touched on the stack, so the delegation code can run against an arbitrary function With delegation code that runs against any vtable entry, we can use the same vtable as a blind delegator for arbitrary objects Although this code has a small amount of overhead, it is clearly much faster than writing a delegation function in VB, where all of the parameters are touched Calling through a blind delegator does not have a significant performance impact To move from a fully blind delegator to one that is useful for aggregation, you have to add a couple of member variables and override the IUnknown functions The first new member is m_punkOuter, a pointer to a controlling IUnknown This
PDF 417 Drawer In Visual C#.NET
Using Barcode generator for Visual Studio .NET Control to generate, create PDF 417 image in Visual Studio .NET applications.
OBJECT DESIGN CONSTRUCTS
Make PDF 417 In .NET Framework
Using Barcode generator for ASP.NET Control to generate, create PDF417 image in ASP.NET applications.
IUnknown establishes the object's identity An m_cRefs member is also added to maintain a reference count The replaced QueryInterface function simply forwards the QueryInterface call to m_punkOuter, so the wrapped object has the same COM identity as the controlling IUnknown The delegation structure is shown in Figure 5 1 IUnknown Hooking Visual Basic provides an implementation of the IUnknown functions for you However, aggregation makes it necessary to gain control over the QueryInterface function to make the object respond to a request for an interface that the compiled object doesn't know it supports All QI calls go back to the controlling IUnknown, so any manipulation needs to be applied to the controlling IUnknown The goal of hooking the IUnknown implementation is to receive a callback when QueryInterface is called on an object (and to make this easy to implement in VB) An IUnknown hook is very similar to a blind delegator, but an IUnknown hook modifies an object directly instead of wrapping the object Hooking an interface is surprisingly simple The value of the pointer to an object is also a pointer to its vtable To hook the functions in the vtable, simply record the current vtable
PDF417 Creation In .NET
Using Barcode drawer for Visual Studio .NET Control to generate, create PDF 417 image in VS .NET applications.
Figure 5 1
PDF417 Encoder In VB.NET
Using Barcode drawer for Visual Studio .NET Control to generate, create PDF-417 2d barcode image in Visual Studio .NET applications.
Redirecting vtable functions in the blind delegator
Printing EAN-13 In Java
Using Barcode maker for Java Control to generate, create European Article Number 13 image in Java applications.
ADVANCED VISUAL BASIC 6
Generate Bar Code In Java
Using Barcode drawer for Java Control to generate, create bar code image in Java applications.
pointer and overwrite it with a pointer to a replacement vtable The vtable call now arrives at the alternate function, which restores the object's vtable to its starting value and forwards the call Before returning, the hooked state of the object is restored, as shown in Figure 52 The VBoost objects included with this book provide IUnknown hooking capability The fastest implementation of the hooking functions is in the C+ + VBoost6DII implementation, but the functions are also available (using many of the techniques from this book) in the compiled in version of the VBoost objects found in VBoostBas This implementation provides callbacks through the IQIHook interface before and/or after the internal QueryInterface call has completed It also provides an opportunity to block the requested IID or to map it to a different value You can use the IQIARHook interface to watch the AddRef and Release calls as well
Paint Code 128 Code Set C In Java
Using Barcode generation for Java Control to generate, create USS Code 128 image in Java applications.
The IUnknown hook provides a complete replacement vtable for the controlling IUnknown of a VB object, allowing you to customize the QueryInterface call
Make Barcode In Java
Using Barcode creator for Java Control to generate, create barcode image in Java applications.
Making GS1-128 In Java
Using Barcode maker for Java Control to generate, create EAN / UCC - 13 image in Java applications.
Bar Code Maker In VB.NET
Using Barcode drawer for .NET Control to generate, create barcode image in VS .NET applications.
GTIN - 13 Recognizer In VS .NET
Using Barcode scanner for .NET framework Control to read, scan read, scan image in Visual Studio .NET applications.
Barcode Drawer In .NET
Using Barcode maker for Visual Studio .NET Control to generate, create barcode image in Visual Studio .NET applications.
Bar Code Creator In Visual Studio .NET
Using Barcode printer for .NET Control to generate, create barcode image in VS .NET applications.