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System commands

Question: Is there a way for me to issue system commands (for example, DOS commands: dir, md temp, etc.) from within a C++ program? Answer: You can use the C

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How do I get a null-terminate string in PB?

Question: When I use Windows API functions in PB, the null-terminate string is often needed. For example, when I use GetSaveFileName,the parameter lpstrFilter is really a trouble to me. Please

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Image Change Script

Question: I am trying to get an image change script to be downward compatible, but Internet Explorer 3.0 does not recognize MouseOvers. Is there another way to do an image

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Accessing individual pixels

Question: I’m developing a VB program that requires manipulation of pictures. I can read them in and display them without any problem, but I have no way (that I can

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Client Licensing

Question: What is the most cost-effective engine and method for licensing clients in client/server applications? Answer: For PowerBuilder applications, the runtime license for clients is free. You can have a

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Virtual functions

Question: If I have an abstract base class with a pure virtual function called get_data(), how do I declare the function in inherited classes to have different return types than

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Powerbuilder import utilities

Question: I would like to know if there are any PB import utilities that can import Excel files into a datawindow, datastore, or database table. Answer: PowerBuilder 6 can import

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Year 2000 compliant

Question: Which versions of PowerBuilder are year 2000 compliant? Answer: PB5.0.4 is year 2000 compliant. All versions before that release had a few minor problems that would not affect most

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Blob comparsion

Question: How can you tell if blob1 = blob2? Answer: You can just use: IF blob1 = blob2 THEN I have used this in the past to compare bitmaps to

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Different develop/deploy operating systems

Question: What are the issues involved, if any, if your development environment uses Windows NT and you want to deploy the application to a Windows 95 environment? Answer: There are

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Datawindow column sorting

Question: I am looking for a way to display an arrowin the the “sorted column” heading to indicatethe direction and column sorted. This functionality can be seen in MS-Exchange. Answer:

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ToolBar

Question: Can I change the font size of the ToolBar text for the application (not the development painters)? Answer: No. The font size is taken from the user’s operating system

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Scaling DW

Question: How can I scale down a DW object? Why is the DW object Ruler inch size much bigger than a real inch size? Answer: You can scale a datawindow

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Read specific number of chars from file

Question: I am a rookie at PowerBuilder. I use PB 5, and I can’t seem to find a function that reads a specific number of chars from a file into

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Powerbuilder / application directory

Question: How do I get the application directory for a PB5-16 app? Answer: You can use the API call GetCurrentDirectory when your application starts to find out its home directory.

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Unions in C++

Question: I am trying to find some information on Unions in C++, specifically syntax and some type of example and perhaps a discussion as to when and why they are

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Draw order of dynamic datawindow objects

Question: How can I control the draw order (i.e., BringToFront, SendToBack) of datawindow objects dynamically created in the deatil band? Answer: At design time you can layer objects by using

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Weird error message (classes related)

Question: I can compile all of my .cpp files (they were written by my teacher), but I get error messages when I try to run them. I get a make

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How to terminate a program safely?

In standard C, the functions abort() and exit() perform an immediate program termination, regardless of where they are called from. Although this also works in C++, it is usually not

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Local SQL

Question: In Delphi 1 I am trying to emulate the “..” function for wild card search in Paradox in Local SQL. I am aware of ‘like’ but it is not

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Using Output parameter with TQuery

Question: In a TQuery component, I use the SQL property to call up a stored procedure which is kept on a MSSQL server. The string used is ‘Execute [nameofproc] :param1,

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API functions

Question: I want to ask you how can I run windows applications inside of Delphi applications (for example notepad.exe)? Answer: It’s actually even simpler than that… Look in the tips

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Telling your program about modifications

Question: An ordinary Stringgrid with 5 columns and 7 rowsThe user wants to add 1 or 2 more rows. So farI know how to write the code! But where do

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Converting strings to reals

Question: I am trying to read in a value of pi/4 from an editbox. Is there a built in command to convert it to a real from a string or

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Copying a file for source to target in Delphi

Question: How to I copy a file from a source to a target in Delphi. I have been trying: SourceId := OpenFile(Source, FileStructure1, of_Read); if SourceID = -1 then ShowMessage(‘Unable

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Beware of throwing exceptions from a destructor

The most plausible way to report a failure during object construction is by throwing an exception. However, this is not recommended for destructors. The problem is that a destructor may