Calvin Hsia's WebLog

I have 23,000 digital pictures and movies taking many gigabytes of storage from the past decade or so. The more recent ones are larger, because higher resolution cameras were more readily available. I have a few copies of the entire collection on various...

Before VFP7, it was very difficult to get an object back from a DECLARE DLL call. I added the “OBJECT” type for VFP7 which allows you to call a DLL which returns a COM object reference. Luckily, most COM objects are created from other COM objects, and...

Of all the naturally occurring foods/drinks that humans normally ingest, is it true that all but two of them contain carbon? In any case, these 2 are very common. Maybe there’s a candy bar I don’t know about that doesn’t have carbon<g>. (Of course...

At Southwest Fox conference I presented a sample calling a VB.NET server to do regular expression matching . Here’s the sample I used. It gets some HTML from my blog and parses all the hyperlinks (looks for the HREF tags) and puts them into a VFP table...

My daughter earned a 4 th place trophy out of 100 competitors in her division at a chess tournament, far ahead of all other unrated players. As a proud parent, I wanted to get a photo and video of the trophy presentation to hear how the award was presented...

I’ve seen demos of Excel 12 and it’s conditional formatting Data Bar and thought it was cool. In each cell, it draws a colored gradient bar with a width proportional to the cell’s value, making it easy to spot the largest/smallest values. So I wrote...

It was very impressive to see a computer using FoxPro helping a 15 year old drag racer win competitions. When I started reading about it, I thought it must be some sort of simulation: don’t you have to be older to drive? Then I saw the video, which clearly...

In VFP, there are many features to call external code, such as ActiveX controls, COM servers, DECLARE DLL or SET LIBRARY TO . In older versions, you could even LOAD and CALL machine code. If such external calls caused a crash for some reason, what should...

When developing the Watson error reporting features (see Dr. Watson: Please send in your error report , and What is a C0000005 crash? , What was Dr. Watson's original name? )) it was useful to cause a crash intentionally In VFP we have a simple...

We received a bug report Steps to Reproduce : 1) Create MyButtonClass1 class of MyButtonLibrary1. Add code to click method. 2) Create MyFormClass1 class of MyFormLibrary1. 3) Add commandbutton of class created in step1. Add code to commandbutton...

Not even three months of school have passed, and I’ve already received a request for school photos for the yearbook. Simple: bring up my VFP Picture Query program , type in “School”, date range since September 2005, and presto: a SQL Select query of my...

You can determine the last time your Administrator password was changed, which could have been the first time you started your computer (if you haven’t formatted your hard disk or changed the admin password) This code calls NetUserGetInfo to get user...

I read A 'Rand'om Word Trick For You about inserting “Random” words into Word for sample data. It actually puts in a fixed sentence (“The quick brown fox jumps over the lazy dog”) multiple times, which isn’t random at all. That reminded me of the...

Here I described how VFP generates executable code and runs it for early and late binding COM clients and implementing COM interfaces. However, there is an important issue with generating and running executable code in the same process. A computer...

I remember early versions of FoxPro had the LOAD and CALL commands (try typing them in the command window!) that allowed you to put binary code directly into memory and run it! Back about 20 years ago, I wrote code in Foxbase that I hand assembled...

When I’m at a breakpoint debugging some C++ code, sometimes I drill down into members of variables to inspect values. The way C++ implements inheritance, there is a virtual function pointer table, often called a vtable. The Visual Studio debugger allows...

The BINDEVENT( ) Function allows you to attach code to run when other code is executed. It’s sort of like an event hook. The first example below has a method called “Foobar” which is called to return a value. After BindEvent is called, the method is...

At the SouthWest Fox speaker dinner we were talking about continued (or infinite) fractions. I posed this question: What does this expression evaluate to? 1 + 1 _________ 1 + 1 ________ 1 + 1 _______ 1 + 1 ______...

If you start Task Manager (Ctrl-Shift-Esc) and display the Applications tab, you will see a list of running applications. Once in a while an application shows as “Not Responding”. How does Task Manager figure that out? A simple way to determine...