Question: How do I save data entered in a list box at run time without resorting to a text file or having to deal with the overhead of a table?

Question: Is there a way under Delphi 3 and 4 to determine if a previous instance of the application is already running? Answer: Yes, there is a way to determine

Question: I am finding it difficult to check whether an error has occurred in selecting a drive when it is not available at the time. I have tried to use

Question: I am unable to post records permanently to Paradox tables using Delphi 3. The records appear in the table object but disappear after I exit Delphi and start another

Question: How can I make the contents of a table change when the user selects a different radio button? Just like “Button” input type has an event called “onClick,” is

Question: Hello from France,I’m on Windows NT4.0 with SQL Server 6.5and Visual Interdev. I use the DataForm wizard to connect to a data base. When I’m on the xxxxlist.asp with

Question: I am trying to migrate an Access97 database application to a Web-based application. I bought InterDev because it purportedly makes this process easy. But I cannot create a form

Question: I know how to use the new RecordSet control from VI6 to display records into a Grid; but how do I implement a query at runtime? For example: SQL

Inner classes often make your programming task easier by eliminating the requirement to write parameterized constructors for your classes and to pass references as parameters. A method in an inner

Sometimes it’s necessary to create your own RDS server object because of some inherent limitations of the built-in RDSServer.DataFactory object. If you find it necessary to build your own version

Inner classes are useful for instantiating and registering listeners on event sources. When should you use an anonymous inner class and when should you use a regular inner class? If

Question: How do you protect an application with a password and store it in the application’s exe-file? Answer: You’d have to hard code the password in. Then in the FormCreate

Question: I’m developing a program that lists all of a shop’s clients and the items that they purchased. The problem is that if some clients haven’t bought anything, they don’t

The way you create a set of radio buttons is significantly different between Swing and the AWT. With Swing, you instantiate the buttons and add them to a group object

Radio buttons behave in the same mutually exclusive way in Swing and the AWT. However, the way that you create a set of radio buttons differs significantly between Swing and

Using Swing, you can easily create hidden buttons similar to the Back button used in Netscape Communicator 4. Hidden buttons look like normal graphic elements on the screen until you

Infrastructure functions that are used extensively should adopt the “trust the programmer” policy by not performing additional error checking. This policy is widely used in C/C++ standard libraries. For example,

An empty class doesn’t have any data members or member functions. You’d think that the size of an object of such a class would be zero. However, the Standard states

Andrew Koenig devised an algorithm for resolving namespace members’ lookup. This algorithm is used in all standard-conforming compilers to handle cases like the following: namespace MINE { class C {};

Operators new and delete can be declared in a class scope. However, the Standard prohibits declarations of these operators in a namespace. Why is this? Consider the following example: char

This small subroutine iterates through and closes all databases in the Databases collection of the Workspaces object. For each database in the collection, it iterates through each Recordset and closes

To return to a previous location in your code, press Ctrl+Shift+F2. This way you don’t need to set bookmarks. VB only keeps track of the last eight lines of code

The ID (counter field) of a newly inserted record is available immediately after the AddNew method executes. Retrieving the ID at this point means you don’t have to mess with

To quickly go to the code for a called function, subroutine, or property, simply place your cursor on the called routine and hit Shift+F2. VB will immediately go to the

In the tip, “Please Stop Printing!” [“101 Tech Tips for VB Developers,” Supplement to the August 1997 issue of VBPJ, page 13], the code works fine with one exception. If

If old words or marks have dried on a white board and you can’t wipe them off, write on top of them with a fresh pen and then rub them

Use this code to create a comma-separated value (CSV) file from a recordset based on a SQL query. A number of applications, including Excel and Access, can read CSV files:

Question: If I make a C++ library and supply it to a clientwho does not have a C++ compiler, can theycall my C++ functions from their C routines?That is, is