Re: How to read Ladder diagrams? - C# Discussion Boards

How to read Ladder diagrams?

2-Jun-04 4:30

A Hashtable doesn't care about order. It's uses hashes to place items in buckets and resizes itself when needed. This is a relatively simple data structure that is taught in most beginning and intermediate programming classes.

Instead, use a System.Collections.SortedList which also impements IDictionary.

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sachinkalse1-Jun-04 22:49

sachinkalse

1-Jun-04 22:49

How to read Ladder diagrams using C#? Is there any way to insert ladder diagrams in .rtf file?
please guide

Heath Stewart2-Jun-04 4:23

2-Jun-04 4:23

Same as any other document: write a parser than displays objects. Since there doesn't appear to be a standard for a ladder diagram document, you have to design your own data structures. This is really no different than what charting applications would need to do. Using .NET runtime serialization with an abstract object model would probably be best. The implementation is entirely up to you.

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sachinkalse2-Jun-04 16:18

sachinkalse

2-Jun-04 16:18

could you please elaborate more.
thanks

Heath Stewart2-Jun-04 4:27

2-Jun-04 4:27

As it turns out, there's one standardization project currently in design phase. See http://www.bbdsoft.com/control.html[^]. It uses an XML document to save the ladder logic. In this case, it'd be better to use XML Serialization (see the System.Xml.Serialization namespace in the .NET Framework SDK), but to still design an abstract data model where the objects are still drawn on the screen using suitable representations. There is a Java project already using this recommended spec I linked above if you want examples. See http://www.bbdsoft.com/j-ladder.html[^].

It's amazing what a simple search for "ladder diagrams" on google[^] can turn up. Roll eyes | :rolleyes:

As far as embedded this in an RTF, the easiest way would be to allow your application to draw the images to a device context instead of the screen device context and then save that to an image. Simply embed the image in RTF. Attempting to use OLE requires a good working knowledge of OLE, how to embed OLE in RTF, and how to expose CCW effectively from .NET components.

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sachinkalse2-Jun-04 16:24

sachinkalse

2-Jun-04 16:24

Images won't help here, as, if we compress the image of ladder, the thin lines may disappear and the ladder become useless.
regards

Heath Stewart3-Jun-04 3:36

Selecting one value from a cookie

3-Jun-04 3:36

Look, there is no library for reading or writing ladder diagrams for .NET that I could find by doing a quick search on google, which you really should've tried first - researching is just part of development.

You have to write your own. As I mentioned, there is an XML dialect being designed for a standard document format, but nothing says you have to use it. How you implement this is completely up to you. This is all part of designing an application.

I gave you a couple ideas. You can use images and can even use vector graphics like EMF, which .NET can save. This means that if the image is scaled up or down (down to a degree, but that's pretty small) it looks the same because the strokes and shapes are recorded, not simply pixels. EMF is an enhanced version of WMF.

If you want to know how to embed OLE objects and expose your drawing surface as a CCW, then you need to read a heck of a lot of documentation about OLE, COM, and CCWs in .NET. The former approach is much easier and supported by more RTF viewers (even on different platforms), where OLE would not.

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_Searcher_1-Jun-04 22:47

_Searcher_

1-Jun-04 22:47

Hello!

I'm having some trouble geting one value (and only one) from my cookie, and would realy appreciate some help. This is my code:

HttpCookie UserCookie;
UserCookie = new HttpCookie( "strUserID" );
UserCookie.Values.Add("group", "1");
UserCookie.Values.Add("sim", "2");
Response.Cookies.Add( UserCookie );

How do I get only "group"?

Thanks!

-- Evil geniuses for a better tomorrow --

Re: Selecting one value from a cookie

Heath Stewart2-Jun-04 4:21

MultiLine datagrid header

2-Jun-04 4:21

If you read the documentation for the Response.Cookies property (rather, the HttpCookieCollection class that Response.Cookies reflects), it should be obvious:

string group = Response.Cookies["group"];

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denizmercan1-Jun-04 22:32

denizmercan

1-Jun-04 22:32

How can I do this.
I use \n in the header. But it doesn't show the second line.
thanks in advance.

Torsten Mauz1-Jun-04 23:23

Torsten Mauz

1-Jun-04 23:23

You need to use html to affect the layout when rendered to the browser, so in this case you should use either <br/> or <p>...</p>.

You will probably find if you view the source of your page that it has put the newline in there but, as the browser will ignore the newline, it doesn't do you much good.

HTH

denizmercan1-Jun-04 23:28

denizmercan

1-Jun-04 23:28

sorry I forgot to say, I need to do this in C# windows application.

Torsten Mauz2-Jun-04 0:01

Torsten Mauz

2-Jun-04 0:01

Right I've managed to munge a work around for this. Perform the following steps:

1). Add a TableStyle to the table styles collection for the datagrid (I just left the defaults on for this).

2). On the actual datagrid (not the table style you just created), change the HeaderFont size property to something bigger (16 got me two lines of text).

3). Use \n to add line breaks.

This should sort you out. Let me know if you can't get it working and i will post some a demo for you.

HTH

denizmercan2-Jun-04 0:31

denizmercan

2-Jun-04 0:31

that works. Thanks a lot

Torsten Mauz2-Jun-04 20:27

Torsten Mauz

2-Jun-04 20:27

No problem, but it should be noted that this is not a very nice way of fixing things. I'm sure if you made this an ownerdrawn control and handled the painting yourself, you could fix things without having to trick the control about the font-size. Although, i suppose compared to just twiddling a couple of properties it's a lot more hassle doing things properly Smile | :)

WMI Classes

RockmanHero20031-Jun-04 22:31

RockmanHero2003

1-Jun-04 22:31

I'm new to WMI Classes and Device structures. Right now, I'm working on a project that is a frontend to cdrecord for windows.

I'm using the WMI classes to access the CDROMDrives.

I was wondering if there was some magic formula to determine if a Drive is a burner or not. I've got it right now so that all CDROM Drives will be detected, including non burning drives.

Can I do that with WMI Scripting?

RockmanHero2003

Re: WMI Classes

Heath Stewart2-Jun-04 4:18

Service - front-end communication

2-Jun-04 4:18

First, I would recommend downloading and installing either or both of the VS.NET add-ins (differ for VS.NET 2002 and 2003):

There are, IMO, indespensible tools when working with WMI. They are add-ins to the Server Explorer of VS.NET and you can even generate typed wrapper classes for CIMv2 classes to add to your project, as well as just browse the classes (a default set is added during installation - you can always add more classes).

Looking at mine, I can give you few alternatives. You could infer that the drive is a CD-R or CD-RW from the Name property. If there's media in the drive, you can also determine if it's writable by checking the name of the MediaType library. A non-writable CD drive wouldn't recognize blank media correctly.

Finally - and probably the best way, is to check the Capabilities and <coded>CapabilityDescriptions property.

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LorenzoDV1-Jun-04 22:09

LorenzoDV

1-Jun-04 22:09

I have a network application consisting of a core class (and underlying class structure, of course) and a GUI Form. Now they run together as a Windows Applications.

However, I found it would be very suitable for this app to run as a Windows service in the background. The problem is: sometimes the user who happens to be logged on may need to interact with the service or check its state. I don't want to put a GUI in the service (that's not possible - it should run out of the user context), but have a separated GUI application that can be run and connected to the service process, check state, issue commands and then disconnected, with the service remaining active.

My question is, what communication means should I use? I thought about opening a local socket... is there another way? I've seen a couple of services with front-ends, how do services deal with this problems?

Thanks.

Re: Service - front-end communication

Heath Stewart2-Jun-04 3:36

Re: Service - front-end communication

2-Jun-04 3:36

You can send simple commands (and I do mean simple) to the service via the ServiceController and it's ExecuteCommand method.

If this isn't suitable (really only good for telling the service to do pre-defined tasks), then the best way is using .NET Remoting. It may be a little difficult to understand at first, but once you understand it it's excellent. If you're familiar with XML Web Services, you've already got a pretty good start. .NET Remoting - unlike XML Web Services - doesn't really care about the transport or serialization channel (though there are some restriction depending on how the remoting object is hosted). The .NET FCL provides both a SoapFormatter and a BinaryFormatter, as well as a TcpChannel and HttpChannel. For the best performance, I recommend configuring your remoting object and the proxy (runs on the client) so that it uses the BinaryFormatter (faster serialization and much less overhead) and the TcpChannel for two-way communication and faster transport than HTTP.

There are lots of good articles here on CodeProject about .NET Remoting. I recommend anything by Roman Kiss (although some knowledge of .NET Remoting is required since his articles are often for more advanced developers with .NET Remoting).

You can also read about it in the .NET Framework SDK: .NET Remoting Overview[^].

I would also recommend 1 or both of the following books:

"Microsoft .NET Remoting" from MS Press[^]
"Advanced .NET Remoting" from Ingo Rammer[^]

The biggest advantage over using TCP sockets is that you don't have to define your own protocol; it's already done for you. You also don't have to worry about the serialization of complex objects. The one advantage of using a TCP socket with a solid protocol design is that you could communicate with it using just about any language, framework, or platform.

This is the typical and recommended solution for communication between .NET projects.

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LorenzoDV2-Jun-04 10:39

LorenzoDV

2-Jun-04 10:39

Thanks for the answer!
My fear was exactly having to create a protocol to communicate.

I worked with web services in Java and know a bit about them, so it should not be a problem to understand remoting, I think. I'll read the articles.

Another doubt, will I be able to register to events on the server object, or will I have to stick with RPC pattern, making "poll" calls? Thanks again.

Re: Service - front-end communication

Heath Stewart2-Jun-04 10:46