
Since 1998, DevX has helped people start businesses, build websites, and provide enterprise technology to people globally. Interviewing the likes of Microsoft’s co-founder, Steve Ballmer, the publication brings comprehensive, reliable, and accessible insights to the Internet.
ShellExecute is one of the most flexible Win32 APIs. Using ShellExecute, you can pass any filename, and if the file
You can allow users to resize a control?just like in VB design mode?with a mouse, using two simple API calls. You can resize the control?top-left, top, top-right, left, right, bottom-left,
When you create generic functions, remember that many functions are a two-way street. For example, many general utility modules contain both LoWord and HiWord functions. However, to compose a Long,
This is an update to [
Question: I’m using a function named Browseforfolders() that uses the following code: Private Declare Function SHBrowseForFolder Lib “shell32.dll” _Alias “SHBrowseForFolderA” (lpBrowseInfo As BROWSEINFO) As Long and the declaration of this
Question: How do I run a SQL stored procedure from within Visual Basic? Answer: The easiest way is to use the Execute method of either the Database object (DAO) or
Question: I have two varibles, one containing the name of another varible, and one containing a string. How can can I set the varible that’s name is contained in the
Question: I have a database of strings of hex numbers and I want to convert them to decimal. There doesn’t seem to be a function for it, but can you
Question: I want to Transfer records from one Database table to other Database table but through VB. I can’t write a query such as I can for SQL Server: Insert
Question: I am building an SQL statement to Insert and Update records. If the user enters a double quote mark in the text box the SQL statement treats this as
Question: I have a struct: struct mystruct{ DWORD dw_Id;}*pMystruct; In the following function I want to pass the address of ‘dw_Id’ which is a member of mystruct. How do I
Question: When using Queryinterface in COM, why is the interface pointer cast to void** andwhy is it passed as a pointer to a pointer (double indirection)? Answer: This is because
Question: If I use malloc locally in a function do I have to use free as well? Won’t someother piece of the application eventually chew up the memory I mallocd,
Question: I’ve writen a program that simulates a heat circulation, and one of its functions performs an optimization processwhich uses a lot of dynamic memory. Myquestion is, can I use
Question: Is there an equivalent of the CallByName function that returns a list of proprety and method names for an object? Answer: No, there isn’t. If you need that, you
Question: What is a concrete class? Answer: A class that is neither derived from another class nor is meant to serve as the base for other classes is a concrete
Question: Do you know of a tool that helps to either eliminate or identify dead code? Answer: You don’t need a special tool to detect dead code. Every decent compiler
RuleZero 1.2, the easiest and fastest add-on tool for creating database-driven Web pages in Visual InterDev 6 is now free. You can get a copy from Vertigo Software’s site, www.vertigosoftware.com.
Several member functions of std::string might throw exceptions. For example, if you use a very large number to specify the initial storage size, string’s constructor will throw an exception: string
Suppose you define a the following list object and you need the address of one of its elements: std::list li; std::list ::iterator iter = li.begin(); In many contexts, iter functions
It’s perfectly legal to call a member function?virtual or not?from a destructor. However, you should avoid calling a member function that accesses data members that have already been destroyed. For
On exit from a scope, destructors are called for all local automatic objects that are declared in that scope, in the reverse order of their declaration. For example: void f()
Consider the following program: int func(); main() { int n = 0; int arr [2] = { func(), n}; /* ok in C++, not in C */ } A C
A POD (plain old data) type is a union, struct or class with no user-declared constructors, no private or protected non-static data members, no base classes, and no virtual functions.
To zero-initialize an object of type T means that the memory storage occupied by the object is set to binary zeros. More precisely, if T is a built-in data type,
Consider the following class: class A // lacks default constructor { public: A(int x, int y); }; Class A doesn’t have a default constructor. Therefore, the following array declaration will
The standard <math.h> header declares the function ceil() and floor(). These function round the fractional part of a floating point number. ceil() returns the smallest integer that is no less
You’re probably familiar with const member functions such as: class A { public: int get_x() const; // can’t change A’s state }; C++ also supports volatile member functions. You declare
In the body of a non-static member function, the keyword this is a non-lvalue expression whose value is the address of the object for which the function is called. However,











