.net and visual foxpro interoperability - c#

I do not have much knowledge about the interoperability between .net and visual foxpro. Is it possible to access all controls, forms etc using com and modify and add features in .net and vice- versa. How does the interoperability works

Most of the things can be done using foxpro.
I'm currently migrating a large VFP application.
There the VFP Application hosts an .net com assembly.
You can also put .net Controls in a active X and put dem on the VFP Applications.
But there may be issues concering refreshes and display bugs depending on how your application is implemented.
The FoxPro database can be accessed via oledb. But it is not thread safe and hase some issues getting correct data.
All of these topics are to big to explain them in a single post. but Rickstrahl has some very good tutorials on his website.
One example here
Let me know if you have any further questions.

Try looking at these resources.
Chapter 15 from .Net for Visual FoxPro Developers.
This gives you step by step instructions on creating a Com Sever in Visual FoxPro
and how to access it with .Net.
.NET Interop for Visual FoxPro Applications

Related

What software I'll need to become proficient in the Microsoft endorsed languages?

I have a free MSDN account and now that I am proficient in C/C++/Java, and know some JavaScript, PHP and MySQL, I want to learn some proprietary languages from Microsoft. I am looking to experiment with everything within the next several months - C#, ASP, VB, things I haven't even heard of [insert suggestions here], what have you.
However, I know nothing about the languages and the software that I need. I don't even know what .NET is.
I don't know if I should be downloading Visual Studio 2008 or Visual Studio .NET. I don't know if I need .NET Framework 1.1... there's just so much stuff on MSDN. I don't even know how begin to do any ASP... Please don't flame me.
I was hoping that with your help I can make a complete list of languages and software and start experimenting. Which framework do I need? Should I install a regular Windows, a professional version or a server? What do I need to do DB related stuff?
There are a lot of questions here and I would like to get an answer to each, so please contribute with whatever you can. I am devoting 2 days to downloading and researching the topic myself, but I would like some [professional] people input, because googling these things just isn't enough.
A good start would be Visual Studio 2008. This is the IDE and is the current version.
The installer will make sure that you have the correct versions of .NET installed, and also includes the database SQL Express.
You can install this on any version of Windows later than Windows XP Service Pack 2.
Since you come from a Java/C/C++ background, you may find C# most similar to what you are used to.
Personally, I would ignore VB.NET and look at F# next. However, that is not included in Visual Studio before 2010, but you can download a preview for free that works with Visual Studio 2008.
The express editions are a good start, they are free. the install should install any dependencies you need (the run time etc). There are plenty of other add ons (ASP.NET MVC is currently an add on for anything less than the 2010 beta of Visual Studio).
I included a link for the 2008 express editions which are the most current released versions
Visual Studio Express 2008
I agree w/ the poster who said you need to focus your efforts. First question: are you trying to learn this for developing for the web, or for desktop?
If Web, learn ASP.NET, if not, not.
Under ASP.NET, are you planning on just trying it out to get something up quickly, or do you want something more long-term, possibly leveraging your PHP/MySQL/JS skills? If the former, go for "regular" ASP.Net (aka Webforms), otherwise, go MVC (which will probably seem more familiar coming from PHP).
As far as languages, that comes down to preference, they're pretty interchangeable. I prefer C#, and if you're good at Java that may be true for you as well.
Tools, if you have an MSDN subscription, then Visual Studio 2008 Pro (or Team) is the way to go, get the latest SP's and you're up and running.
Paul
MS-SQL Server 2008 along with .Net 3.5 would be a couple of other suggestions that I think may be worth tossing out there. The SQL Server is Microsoft's relational DB that may be worth learning a little so that you could compare it to MySQL in some ways if you are into relational DB stuff. The .Net 3.5 is the latest version of the framework and may not be a bad idea to begin with some of the newer functionality within the framework with things like LINQ for example.

Using MS Access as a .NET Application Backend [closed]

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I am the lone .NET developer in an non-IT organization. I've been asked to develo ae .NET application using Microsoft Access as the back-end (existing DB).
I don't know where to start.
Since I'm developing by myself, what should I keep in mind to avoid during development? What situations does only a lone developer face?
Please include Microsoft Access specific advice in your answer, since that is germane to the question.
Where to start?
Choose a development environment (I would suggest Visual Studio 2008 Express or Professional, depending on the budget and the need for features of the Professional version)
Even for one single developer: choose a Version control system !!!! (Subversion has only little administrative overhead, fine for one developer)
Choose a .NET Framework version (3.5 is fine unless your application has to run on Win2K; for Win2K use .NET 2.0)
Choose a mature programming language (C# or VB.NET, what you or your boss likes best)
Choose a GUI technology (for a single developer, I would suggest using WinForms, unless you are going to write a Web application or a command line utility)
Choose a mature DB access technology (ADO.NET works for a lot of things, unless you have very high performance requirements that are better dealt with old ADO/OleDB or DAO)
EDIT: use Google to find some entry examples according to the choosen technology, or buy yourself a book. For example, here is one for C# using OLE DB to access a MS Access DB. This Access site is a good starting point, too.
EDIT2: make yourself familiar with "Microsoft Access" (the Office Application). Not because you are going to use it like a typical user, but you will probably need it for administrative purposes. And the VBA & SQL documentation included will be sometimes helpful, even if you code with C# or VB.NET
EDIT3: for reporting purposes, choose a reporting technology. There are plenty of possibilites here, depending on your needs, your skills and/or budget, for example
Plain ASCII or CSV reports (coded by hand)
HTML or XML reports
using Excel as reporting engine
using a PDF library like Report.NET
using a third party tool like Crystal Reports
You will find a lot of helpful links when you give "report generation .net" to Google, for example this one.
And finally: come back to SO and ask more concrete questions when you come to the point where you have them.
There might be other constraints, depending on what code is already existing in your organization. And I would avoid technologies like F#, WPF or Linq to Entities.
Your question is too vague to give more than just general advice. If you have already developed other .Net applications, then the approach to developing this new application should not really be any different.
Database considerations:
The only things to bear in mind when using MS Access as a back-end database are:
Scalability - MS Access does not
scale very well and is only suitable
for a small number of users
*EDIT: Numbers vary depending on the type of activity the users are performing - for a reporting solution, Microsoft themselves suggest that up to ~100 concurrent users is the maximum - this white paper provides more information *
Security - MS Access does not offer the same sophisticated levels
of security that you will find in
other database products (SQL Server,
Oracle, MySQL)
SQL Syntax - there are some subtle differences in the way you
write certain types of query for MS
Access
Other Limitations - MS Access does not support stored procedures, so all your data access code will have to use inline SQL Commands (command.Type = CommandType.Text)
The maximum database size supported by Microsoft Access is 2GB - keep an eye on the growth of the database
Design considerations:
Does the existing MS Access database already have some user forms and code modules in it? If so, you could use these as the basis for your application - MS Access uses Visual Basic for Applications (VBA) as it's programming language and there are no tools/utilities that I know of that will port VBA to VB.Net
Do similar applications exist elsewhere that could help inform your design?
Keep data access code out of your forms as much as possible - try to keep data access code in a separate class/DLL so that it is easier to maintain
EDIT: as others have suggested, try to avoid having instances of ADO.Net connection and command objects scattered throughout the user interface - put all database connection code in one class/DLL so that it easier to fix/maintain/replace. I'd also suggest putting all your SQL query statements in a separate class or module for the same reason. *
Follow any in-house guidelines that you, or others before you, have put in place.
Keep maintainability in mind - someone after you may have to make changes. Use comments in code and give your objects (forms/variables/function names) sensible names
Take regular backups of your code - put a copy on a network drive or USB drive every day
One point of advice, encapsulate all Access-specific code within a single class. The class should at least be able to:
locate the Access .mdb file
create and open all OleDbConnection objects
It's critical that all Connections are guaranteed to close, so wrapping their use in a using block is a very good idea
(Possibly) build and execute all OleDbCommands (removing the db-specific logic from the consuming components--they should be able to make data-requests and retrieve results while transparently creating the Connection & Command, etc.
For accessing the Access database, you could maybe have a look at NHibernate? As far as I know it supports Microsoft Access and using a library like that could perhaps make things easier if you are going to move the data to some other kind of database later on.
If you are already familiar with a .NET language and MS Access then my advice would be to start off by developing a very simple MS Access database and write a small .NET console application that connects to that database and performs some basic functions e.g. querying/inserting/deleting/updating. Then its just a case of builiding on top of this piece by peice, introducing GUIs/separate libs (dlls) etc on the way.
Unfortunately for you .NET Linq to SQL (ORM) does not support MS Access databases so you will have to develop your Business Objects from scratch (not always a bad thing!).
Here is a good starting point MS Application with C#.
There is a lot of good advice here, all I would add is be sure to build all your data access and modifying classes behind a well defined interface(s). I am sure there will come a time when this application out grows MS Access and having well defined interfaces will make upgrading to another database easier.

Create COM Surrogate server (exe) in C#

I know how to create a COM DLL (a Class Library) in C#. Is it possible to create a COM Surrogate EXE using C#?
This would be a standalone server capable of launching and hosting COM objects, which would then be accessible to COM clients.
The default surrogate process for COM - the thing that hosts COM DLLs, aka the COM Surrogate - is dllhost.exe. It is possible to create a surrogate process in C++. This article explains how.
But those APIs are not exposed in wrappers as part of the base class library in the .NET Framework. If you want to write to write only managed code, you need something else.
I see a couple options.
The Visual Studio SDK, a free download that is intended for devs who want to extend Visual Studio. Within that SDK, there's a class lib that has such wrappers. In particular, look at the ISurrogate class.
BUT, the VS SDK license says that the SDK is ok to use only for products that extend or add value to Visual Studio. I am no lawyer, but that is my understanding of the license, which is pretty clear. These terms means the VS SDK would not be useful for general app building.
The one remaining question is, exactly how do you use the VS SDK technically to produce a COM Surrogate using only C# code? Again, here I don't know. I looked in the docs briefly for guides on using the ISurrogate wrapper, but found none.
Use the code in this article.
The article explores a bunch of different aspects around COM and .NET interop. Towards the end of the article it offers source code for building your own COM server in C#, complete with all the p/invoke calls to CoRegisterClassObject() and friends.
I wanted to make same thing and found excellent project example CSExeCOMServer on All-In-One Code Framework. It actually reconstructs normal COM server logic by means of .NET and native calls to Windows API. But it looks all still overcomplicated. I suppose there is no simple and fast way to expose .NET objects as COM in out-of-process server and it is not the architecture of choice.
One option, if you want an out-of-process COM component, is to host a dll in COM+ via serviced components. This only supports dll though, but you could write a shell exe (for standalone use) that simply defers to the dll.
Not quite as simple as VB, but it works.
I do remember somebody showing me a more direct way (no COM+), but I can't for the life of me remember what it was...

Visual Studio 2008 - Sharing Data in C++/C# Multi Project Solution

I have a solution with 2 projects:
a c++ main project
a c# project (display simulator)
Today these 2 apps share data using a loopback TCP client/server connection, but that's not very optimal (timing issues..).
I was wondering if there was a way to access the c# data from the c++ project directly and vice versa? (It seems to be possible with 2 c# projects..)
If it's not possible, what's the best way to implement this with shared memory?
thanks!
Michael
EDIT: thanks for the answers. The 2 projects used to be independant solutions and are both executables - I'm actually trying to merge the 2 into 1 solution / executable.
For info: The c++ app is a PC version of an embedded app - the c# app is a lcd/HMI simulator.
Converting the C++ project to a C++/CLI project might be the easiest way to go. Note however that some code doesn't play well with C++/CLI (we've had problems using libraries that use boost::thread in a managed executable).
You can use COM Interop or Platform Invoke to access native code in C#.
If that's not what you're asking for, please elaborate.
Named Pipes?
For interprocess communication via named pipes you can check out the .NET 3.5 feature
http://msdn.microsoft.com/en-us/library/system.io.pipes.aspx for the C# side. From the C++ side, I assume you know the equivalent :).
There are two ways I know of to get direct access to memory between c++ and c# without the overhead of marshaling/demarshaling and com. If it is required to keep the c++ part of your code native then the only way I know to achieve this is to host the clr from your c++ application. A relatively complicated undertaking. Google "hosting the common language runtime". Then you can load your c# code as an assembly, call into the c# code and provide a common shared memory style interface. Although you will have to write all of the shared memory support yourself as I have found no direct support for shared memory in c#/.net.
The other way is to compile your c++ code with common language runtime support. This is by far easier and will allow you all the power and glory of c++ while allowing access to clr based data types, and the ability to call back and forth between your c++ and c# code. See "Language Features for Targeting the CLR" in your VS2008 documentation. pin_ptr will become your close friend and ally in this process.

C# Desktop Applications? [closed]

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In looking at the use of C# in a ISV setting, I'm wondering what prominent C# based desktop apps are out there? I can think of only Paint .NET.
Is C# a good idea for an ISV, or should one stick to more native environments like Delphi or even QT?
Of course any experienced based advise or feedback would be appreciated.
Yes, C# can be used quite effectivly to build applications. In regards what applciations are out there, what are you looking for? Big apps, little apps?
I know of a big app that is built on the .NET framework (unsure if C# or VB) and that is Quickbooks.
Developing a Desktop applications in C# is great. Its not just for Web Apps.
WinForms are going to save you huge amounts of time. It really is a first class citizen when it comes to desktop windows development. If interop is a problem you can always use P/Invoke and COM object wrapping that VS does for you.
Done right, it will be a breeze to maintain and update when the client changes their mind on what they want.
Yes, the framework needs to be on the machine, But this shouldn't be a problem if they have ever used windows update. Nowadays what language doesn't come with a run time library. In VS you can create simple installers that include the runtime.
Of course if your gonna deploy to Linux and mono, your mileage may very.
PlasticSCM
If you can control the system requirements for your application, C# is fine. Some end users still (even though we're nearly in 2009 now) object to a 40MB runtime for some reason, so if you're looking to deploy an application commercially, that may be an issue for you. In a corporate setting, though, where there is some standardization of software on users' computers, this is probably not a problem.
Delphi and QT specifically are both problems. Delphi is effectively a dead language. Companies that are using it these days are, for the most part, porting their code away from it as fast as they can (job boards seem to be full of Delphi-to-C# migration jobs these days). You may like QT, but that moves almost as slowly as Delphi in the Windows world, so I would never consider it to be a real option.
More:
Business Plan Pro
Rescue Time client
Sony Vegas
Sql Management Studio
VS 2010 (much more so than VS 200x)
NASA's World Wind
BabySmash
Windows Live Writer
Microsoft Office Accounting
Fiddler 2
Windows Mobile Device Center
AdiIRC
Jetbrains dotTrace
Lots of Lenovo utilities
Planbook
These are just the ones installed on my PC...
I think that Microsoft Expression Blend/Studio is written in C#
Anything done for Robotics Studio, any XNA game (quite a few commerical ones are coming out now)
I don't see why you would not use C# as an ISV. The problem is ensuring that your target market has the .NET framework. If you are using 3.5, you can build a mini version into your distribution though this increases the file sizes for downloads of course.
Some supplemental information to think about:
One of the typical points against doing desktop applications the distribution model is a lot more difficult to manage. With web apps, if you have a large user base, you can do an update and instantly have your entire user base running on the latest version.
With traditional desktop apps, you'd have to send out an .msi or build something yourself.
However, with ClickOnce and the Updater Application Block (http://msdn.microsoft.com/en-us/library/ms978574.aspx), it's so easy to build intelligent updating into your application that it might play very nicely into an ISV plan.
Even though VS 2008/WPF is shrinking the gap, it's typically much faster to develop client applications in the WinForms space that on the web, so I think it's a very viable approach.
I believe TimeSnapper is written in C#
I have worked for an ISV before that used Delphi and it was excellent for their needs. It still produces great native applications and although dieing it is certainly not dead (yet). Until recently I would have recommened Delphi over c# for desktop applications as I had performance and footprint consderations but as .net can now be considered ubiquitous and that the platform is now maturing my opinoin would probably go with c# (over Delphi).
If you need to consider employees, you will find that there are fewer Delphi developers around that c# ones. So you may struggle to entice good devleopers in as you are using that.
That said Delphi is looking exciting again with the Delphi prism VS plugin.
Just as an aside did you know that the c# compiler is written in c++? Delphi was written in Delphi from v1.0
Windows Media Centre is powered by .NET.
I believe that MS use C# to build many of their apps both Windows and Web. At this time, C# is a great language to go with because of the flexibility of the language/framework.
The zune software (v2 and up) is written in c#. Oh, and Sage Timberline Office is written in .net (mostly).
Although it's a developer tool, the excellent open source IDE SharpDevelop was built in C#. I've also worked on another which (despite being semi-commercially-available) I'm not at liberty to divulge. (Very vertical market.)
I'm a huge fan of the C#/WinForms combination, and can't see why you wouldn't go that route if your developers are already familiar with C# and you want to get into the desktop space.
A very prominent example for a commercialy successful application would be Microsoft Visual Studio 2005 itself.
If you are looking into building a client or server application for the Windows ecosystem .Net with C# is an absolut valid choice. You'll get a very rich framework, a great third-party-app ecosystem and a huge community.
If you need a minimal memory footprint for your application or are very hardware centric then C++ maybe an option.
If you want to target the UNIX/LINUX or Apple platforms you should be looking in frameworks more native for the respective platform, though you can get a certain degree of interoperability with the Mono project (But I am not up to date on how complete their implementation of .Net currently is).
I believe the matrox graphics card configuration utilities are using the .net-framework.
I'm still just a student, but for what it's worth (and from other answers preceding mine), there seem to be quite a few apps in C#.
I'd advise working through the book Head First C# (Amazon link). This book will give you a pretty solid idea of what you can do with the language.
=-MDP-=
Creative Docs .NET is a very nice example of C# application.
Microsoft's World Wide Telescope software is written in c#
Who are your target users? Their needs will dictate your choice of language. C# and VB.NET are good general purpose langs, but if you are targeting Mac or *nix, you may want something like C++.
If you're looking for a way to get started quickly, I recently published DesktopBootstrap, which is my attempt to factor out the elements you'll need to get started.
Hope that helps!

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