Foxpro Sample Program

TekTipss functionality depends on members receiving email. By joining you are opting in to receive email. W6iDUsb8/TeuZ4j9EPSI/AAAAAAAABQU/-H6CfnT3Irg/s1600/ffmixt.png' alt='Foxpro Sample Program' title='Foxpro Sample Program' />Using Crystal Reports with Visual Fox. Pro. Your questions answered about this popular report writer. Although Visual Fox. Pro has a very capable report generator, many developers. One of the most popular of. Crystal Reports. In this article, well take a look at what CR has. VFP professional, and the implications of using it with Foxpro. Once upon a time, xBase wasnt a programming language, it was a tool to automatically retrieve and manipulate data. Users of xBase tools werent primarily developers. An online Visual Basic programming reference for both beginners and experts. This site provides tips, tricks, sample code, sample projects, downloads, links, HOWTOs. List of older versions of FoxBASEFoxPro programming tools and their features. Top 25 Wanted Items. AshtonTate Framework VIII, VII, or VI or V or IV 333 Corel Photo House 1. An old photo editing program from Corel Flex OS 190. Foxpro Sample Program' title='Foxpro Sample Program' />I am happy with VFPs own report generator. Why should I switch to Crystal. Reports Put simply, Crystal Reports is considerably more powerful than Visual Fox. Pros own. reporting tool. VFP can handle most reporting tasks, but you sometimes need to. Foxpro Sample Program' title='Foxpro Sample Program' />Crystal Reports, on. Even taking account of the many enhanced features that. VFP 9. 0, CR is still the more powerful tool. Here are some example of things which CR can do much more easily than VFP Intelligently deal with page breaks, for example so that groups are kept. Show different page headers or footers. Print several small reports on the same. Generate cross tabs, for instance with months across to the top. Display drill down charts where clicking. These are just a few examples. In many cases, things which are awkward to do. VFP can be done in CR with a simple command or menu choice. Does Crystal Reports work with VFP data Yes. CR provides three ways of accessing Visual Fox. Pro tables Native access. This is the simplest of the. Fox. 2X tables, that is, DBFs created in Foxpro 2. BASE and Clipper or those created in VFP and copied to Fox. COPY TO. TYPE FOX2. X. ODBC. This method works with any VFP table, including those in a DBC. The. disadvantage is that you need to create an ODBC data source and distribute. Keep in mind too that Microsoft has not updated the. Inventory%20System%20MS%20Access.jpg' alt='Foxpro Sample Program' title='Foxpro Sample Program' />Fox. Pro ODBC driver since VFP 6. OLE DB. This is the preferred method, and. Fox. Pro tables. Can I base my report on local views rather than tables Yes. CR doesnt know or care if the data is coming from a table or a view. If I distribute reports to my users, will they need to install Crystal. Reports in order to view or print them No. As a VFP developer, you will probably want to integrate the reports into. If you do, your users wont need CR itself in order to view. If you prefer to distribute free standing reports, it is possible to. EXE files that you can distribute independently of. CR. This ability was available in Crystal Reports 7. Is it possible to deploy reports on an intranet so that users can view. Yes. There is a component called the Crystal Web Component Server CWCS. This component comes with the Professional and Developer. Crystal Reports. You install it on a web server, then copy your report files RPT. You must also give your users a. Professional and Developer. In fact, there is a choice or viewer programs, aimed at different. For Internet Explorer users, the Active. X control is. usually the best choice. Cayenne Klein Sandy. Once you have done all this, your users will be able to view any of the. When they. do, they will see a report preview window which shows the report exactly as you. Note that this is the actual report, not an HTML rendition of it. The users will be able to refresh the report. I want to print my reports from within my VFP application. Is that. possible with Crystal Reports Certainly. In fact, you can add the full functionality of Crystal Reports to. VFP apps. There are several ways of doing that. The recommended approach is. Report Design Component RDC. The RDC is an Active. X Automation server which exposes the CR object model to. Essentially, it lets you perform any task programmatically. CR itself. For a start, you can open a report. More interestingly, you can modify its contents and. For example, you could let the user choose the fields to. Just about the only thing which the RDC cannot do is preview the report on. Thats because the RDC itself has no user interface. To preview the. report, you need to use another component, known as the Report Viewer control. This is an Active. X control which you drop onto a VFP form. The control will. It is highly customisable, so if. To use the RDC and the Report Viewer control, you will need Crystal Reports Developer edition. Using the RDC, is it possible to run reports which are not tied to any. Id like to decide the data source at run time. If you are using natively accessed tables that is, Fox. X tables see above. With ODBC and OLE DB data sources, you change two properties to switch to a. DBC or a different one. What you. cant do is to programmatically switch between natively accessed tables and ODBC. OLE DB data sources. However, thats rarely a problem. I have heard that Crystal Reports comes with its own programming language. Is this an alternative to Visual Fox. Pro CR has a so called formula language, which is used to create calculated. You can use. it, for example, to dynamically control the grouping in the report or to apply. Although the formula language can add a great deal of intelligence to a. VFP or the Report Design. Component. The formulae are actually part of the report, and are evaluated as. The RDC is used to invoke CR features and to make global. The two techniques are largely. In fact, CR has, not one, but two distinct formula languages the. Crystal syntax and a newer Basic like syntax. You can use whichever one. You can even use them both in the same report. We already have some reports created in CR. These prompt the user for. Is it possible to hide this prompt and. VFP application instead Yes. This is one of the many things that you can do with the RDC. In general. report parameters are not particularly useful when you integrate the report into. If you have an existing parameter based report, the RDC will let you pass the. In Visual Foxpro, the destination printer sometimes gets. Will I have the same problem with CR As you probably know, VFPs report files can store the name of the. Once this information gets into the report file, it. The usual method is to hack the FRX. Foxstuff. article, Controlling report settings at run time. Crystal Reports does not have this problem. In general, the report will go to. Windows default printer on the users system, although the user can select a. Alternatively, if you are using. RDC, you can programmatically specify the destination printer, paper source. This is just a matter of setting the appropriate. How easy is it to export my reports to. Microsoft Word, Excel, HTML or PDF Very easy. The Export menu supports all those. In most cases, you can choose to save the exported. If you. are using the RDC, you can also export your reports programmatically. According to the documentation, it is possible to design a report within. CR itself. How do I go. You cant at least, not in VFP. This is a feature of the RDC, but it only. Visual Basic. On the other hand, its an easy matter to. VFP development environment to the CR report designer. One way to do that is to store your Crystal report files RPT files under. Other files in your VFP project be sure to exclude them from the. Once youve done that, you can open a file in the report designer simply. Modify button. Is it possible to programmatically create a new report from scratch within. Yes. The RDC has a method which lets you create an empty report. Do I need to distribute any special run time files if I use the RDC What. There are certain DLLs that you must distribute with your application, some. If you are using VFP 6. Setup Wizard will. With earlier versions of CR, this was relatively straightforward as there were. DLLs to worry about. With more recent versions, the number of. Once upon a time, x. Base wasnt a programming language, it. Users of x. Base tools. Fox. Base, d. Base, and similar tools to manage their data. Base. was steadily improved and finally developed into a full blown programming. Fox. Pro became a professional development environment which reached. Fox. Pro 2. 52. 6. Almost ten years ago in 1. A procedural programming language became an object. Visual Fox. Pro is not just an object oriented environment. Delphi or Visual Basic. NET. Visual Fox. Pro still contains its roots. Just. try to run a Turbo Pascal 3. Delphi 7. 0. What about your GW BASIC. Visual Basic. NET But Foxbase Till today you can run code. Visual Fox. Pro that you have written in the eighties. Screen output. doesnt look as nice, but you can still run code in VFP 8 almost 2. Visual Fox. Pro is almost fully backward compatible. Thinking. about it this means that a good deal of the code in Fox. Pro and Fox. Base is still. Visual Fox. Pro. This means that object orientation sits on top of. Fox. Pro, and not vice versa. Many strange behaviors of Visual Fox. Pro only become. explainable if you think how you would have done something in Fox. Base, only to. realize that Visual Fox. Pro doesnt do it any different. One warning in advance The following articles tries to. Visual Fox. Pro works internally. The actual internals of Fox. Pro are. the intellectual property of Microsoft and are not publicly disclosed. Everyone. who really knows how Visual Fox. Pro works inside is prohibited to talk about. Non Disclosure Agreement NDA. Ive collected the following. Some information are in the MSDN. Library that Microsoft publishes quarterly some articles only exist in older. MSDN Library. Other information come from sample code that. Microsoft ships. Most pieces, however, come from tests and observation, not. Especially. differences in the behavior of various versions allow to make conclusions on. VFP. Some of the following structures have been extended. Fox. Pro. The Name Table Index NTIIn Visual Fox. Pro we can name various items. To those items. Visual Fox. Pro assigns something called a name. These items are variables. Each of these elements has got a label and a. The visibility scope of a variable, for instance, depends on its type. A field name must be unique. Whenever you create a variable, open a table, and so on. Visual Fox. Pro creates a new entry in an internal list, the Name Table. The position inside this list is the Name Table Index or NTI for short. In this list, every name is assigned a unique number between 1 and 6. Theres just a single global list. This is why you can only create up to 6. Since aliases and. Visual Fox. Pro 6. The management of this list has been optimized in the. Fox. Pro. When you release a name by closing a table or. Visual Fox. Pro doesnt remove the. It only marks the entry as invalid, just like it does with. Items are finally removed by a process called Garbage. Collection. This term refers to the process of removing invalid entries in. Visual Fox. Pro. executes the garbage collection in its idle loop. This loop is entered. Visual Fox. Pro is in a waiting condition caused by READ, READ EVENTS. INKEY, or WAIT WINDOW. This is still true if you use the command with the. You can use this trick to force Visual Fox. Pro to. clean up memory by issuing a WAIT WINDOW NOWAIT. It wasnt until Visual Fox. Pro 7. 0 that SYS1. Fox. Pro 2. 6. at least. SYS1. 10. 4 manually triggers a garbage collection. Its not the same. Visual Fox. Pro does more. Windows. messages. During program execution, Visual Fox. Pro is not in an idle loop and. Until Visual Fox. Pro 5. 0 this. had the effect that more and more entries in the name table have been marked as. This had far reaching consequences on performance, but also. Every time a new entry is added to the name table, Visual Fox. Pro. has to search all existing entries to find conflicting names. For variables. this means to check if a new variable with a lower scope already exist, because. PUBLIC variable when a LOCAL variable of the. For aliases this means to verify that the alias name is not in. This search process caused exponential. While you could measure the creation of the first object. Visual Fox. Pro already minutes to. Application that never reach an idle state like import. Some. functions, too, demanded a new entry in the name table, like the REQUERY. The slow down wasnt the only problem. The. closer an application came to the limit, the more instable it became. If you. were lucky, Visual Fox. Pro issued a too many names error, but. Visual Fox. Pro 6. When. the number of items in the name table approaches the 9. Visual Fox. Pro. automatically initiates a garbage collection. In a program that creates 6. A major improvement came in Visual Fox. Pro 7. 0. All previous. When you create two labels. LOCAL lo. Label. 1, lo. Label. 2lo. Label. Create. ObjectLabello. Label. 2 Create. ObjectLabelVisual Fox. Pro adjusts the name property. The first label is. Label. 1, for the second label Label. Name results in. Label. To make this happen, Visual Fox. Pro registered each object. The consequence is that each object creation takes longer. You can bypass this to a certain degree by assigning a. SYS2. 01. 5 in the Init event. Nonetheless, this behavior limits. In Visual Fox. Pro 3. When that limit has been reached, you cant even open the. Form Designer as it also tries to create objects. Visual Fox. Pro 7. CREATEOBJECT or NEWOBJECT, nor do they. Therefore you can create far more than. Visual Fox. Pro 6. The disadvantage. A small price to pay. Variables, Arrays and Objects. One of the most frequently asked questions that developers. Visual Fox. Pro can only manage up to 6. The answer is a definite. NO. One array counts as a single variable, no matter how many elements it. Because the number of elements is limited to 6. Even in Visual Fox. Pro. you can stores masses of data in memory. Due to performance reasons no real. The reason for all of. Actually, Visual Fox. Pro only. knows to deal, with variables simple variables, that is. The support of. arrays, and later objects, has been fitted into this design. But what is a variable in Visual Fox. Pro Variables in Fox. Pro. can store values of any data type. However, as Visual Fox. Pro is written in C. Fox. Pro variables, as well, have to be stored in a C format at some. Visual Fox. Pro stores variables in a C structure. Even though the. following structure comes from the Library Construction Kit, its probably close. Visual Fox. Pro uses internally, if not even identical typedef struct   char        evtype  char        evpadding  short        evwidth  unsigned    evlength  long        evlong  double      evreal  CCY         evcurrency  MHandle      evhandle  unsigned long evobject Value In addition to the type, theres an entry for each supported. Visual Fox. Pro uses different fields depending on which data type. The structure explains why strings can contain any characters. Visual Fox. Pro deals with. The actual string and objects are not stored directly in. To access strings, Visual Fox. Pro. uses a so called memory handle which will be explained in just a moment. Objects are identified using a not closer documented 3. It might. surprise that arrays are not mentioned at all. Every time a program creates a new memory variable, Visual. Fox. Pro allocates a memory block with the above structure. Its address has to be. Saving these information is the job of the name table. Every entry in the name. The list is limited.