Re: ListView Scrolling [modified] - C# Discussion Boards

Mutithreaded Job execution engine in a Farm environment

sachet sharma13-Oct-09 9:46

13-Oct-09 9:46

Hi,

I have to devleop a application which will monitor a database for new jobs. As soon as a new job is created, engine will pick up the job and process it. Engine will be multi threaded so it can process multiple jobs simultaneously. This will be my first application to use threading so I have couple of confusions:

1. Engine will be running on 4 machine simultaneously so how do I make sure only one engine picksup a job at any one time.
2. In case one engine crashes, How do I restart the jobs for that engine using another engine.
3. How can I monitor the health of each engine.

Any help with the database and engine design is appreciated.

Re: Mutithreaded Job execution engine in a Farm environment

Mycroft Holmes13-Oct-09 14:51

Mycroft Holmes

13-Oct-09 14:51

You may get a better response in the Design and Architecture forum.

1 Implement some logging/flagging system indicating the status of the job and who is doing the work
2 Make you logging/flagging time sensitive (use a timestamp) and have another process monitor the job processing
3 Design you engine to publish its state periodically and have 2 monitor it.

Anything more than general statements like the above are going to require more detail and that is your job after all.

Problem to display relational data in dataGridView in Entity Framework.

hdv21213-Oct-09 9:39

hdv212

13-Oct-09 9:39

Hi i have a simple winform app which have a dataGridView to display Orders table from northwind database. i want to display foreign keys in dataGridView with some related column from reference table, for example display CompanyName instead of CustomerID (even display customerID in comboBox). for this, i change my dataGridViewTextBox column type to comboBox, then bind it to customerBindingSource (which fill out from Customers entitySet), then set DisplayMember and ValueMember to customerID, but at runTime it does not display corresponding customerID for that order (display nothing) for loaded order records.
Here my disegner generated code (the CustomerID is my dataGridViewComboBox column):

this.CustomerID.DataSource = this.customerBindingSource;
            this.CustomerID.DisplayMember = "CustomerID";
            this.CustomerID.HeaderText = "Customers";
            this.CustomerID.Name = "CustomerID";
            this.CustomerID.Resizable = System.Windows.Forms.DataGridViewTriState.True;
            this.CustomerID.SortMode = System.Windows.Forms.DataGridViewColumnSortMode.Automatic;
            this.CustomerID.ValueMember = "CustomerID";

how to workaround the problem ?
regards

zoom like as autocad without quality

dotork13-Oct-09 8:44

dotork

13-Oct-09 8:44

Hi all ,

I want to do without change quality when I was zooming to graphic like as in autocad..

I have to this in C#. Is it hard? or can you give me some hint and links?

thanks

Re: zoom like as autocad without quality

Dave Kreskowiak13-Oct-09 18:16

Dave Kreskowiak

13-Oct-09 18:16

You can only do that if you're dealing with a vector image. Bitmap images will degrade in quality the more you zoom into them.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008
But no longer in 2009...

ListView Scrolling

Zaegra13-Oct-09 7:32

Zaegra

13-Oct-09 7:32

Hello,

I'd like to know if a user scrolls my ListView, since .NET (weird?) doesn't support this. Now I've found several articles (on Google) which tell me I need to create a Virtual ListView and override WndProc. I've done this but: 1) The control is terribly slow, and I can't just drag it on the form, meaning I need to create it in code. Is there any easy way to check if a NORMAL ListView gets scrolled? I also need to know the difference between Scrolling Up, and Scrolling Down.

Please help me out,

Zaegra

Motivation is the key to software development.

Re: ListView Scrolling

Ian Shlasko13-Oct-09 8:08

Ian Shlasko

13-Oct-09 8:08

Talking about WPF or WinForms?

For WPF, I think you can just hook the ScrollViewer.ScrollChanged event, and you're golden...

As for WinForms... Never noticed they didn't have an event for that... Well, you could catch the various mouse events, and look for changes in the TopItem property... Bit easier than hooking WndProc, but not as direct.

Proud to have finally moved to the A-Ark. Which one are you in?
Developer, Author (Guardians of Xen)

Re: ListView Scrolling [modified]

Zaegra13-Oct-09 8:12

Zaegra

13-Oct-09 8:12

Using WinForms $Shucks | :-\$ But I don't care about the internal layout of the Listview, I only need to know if a listview has focus, if the scrollwheel is scrolled. And if so, if it was scrolled up or down.. Can't seem to find anything fitting this purpose. Any ideas on this?

Motivation is the key to software development.

modified on Tuesday, October 13, 2009 2:24 PM

Re: ListView Scrolling

Ian Shlasko13-Oct-09 10:16

Ian Shlasko

13-Oct-09 10:16

Well, if TopItem changes, it means it was scrolled... TopItem is the first item visible... Figuring out the direction would require knowing the content, though.

On the other hand, if you're specifically looking for the mousewheel... There IS a MouseWheel event Smile | :)

Proud to have finally moved to the A-Ark. Which one are you in?
Developer, Author (Guardians of Xen)

Re: ListView Scrolling

Luc Pattyn13-Oct-09 13:55

Luc Pattyn

13-Oct-09 13:55

Hi,

For mousewheel actions, there is a MouseWheel event.

However there probably are other ways to cause a scroll which you also would like to get (for consistency if nothing else), such as clicking in the scroll bar parts, using the arrow keys, maybe performing a find on the content, etc.

Therefore I would be inclined to use the Paint event: just add a handler to Paint, and compare TopIndex to its previous value. You will get some redundant events (e.g. when uncovering part of the Form), but that would be OK I guess.
BTW: I said "add a handler", not "override OnPaint", as you still want the original painting to occur.

Smile | :)

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

Local announcement (Antwerp region): Lange Wapper? Neen!

serial port communication with multithreading

Member 647306613-Oct-09 5:26

Member 6473066

13-Oct-09 5:26

I have to do SerialPort communication that constantly needs to read data from a serial interface (for example COM1). and also identify the strating of first message and ending of that message and also starting of second message. please give me reply ASAP becuase I really stuck in that.

Re: serial port communication with multithreading

Luc Pattyn13-Oct-09 5:54

Luc Pattyn

13-Oct-09 5:54

You had similar questions 3 months ago!?

now start by telling more:
1. is it text or binary data?
2. is it message oriented? what is the minimum and maximum message length?
3. is there a unique byte that indicates end-of-message and is guaranteed not to appear inside a message?
4. is it going to fill the bandwidth, or just a few messages a second?
5. what kind of data is it? is it real-time? can you afford to loose some (as in audio/video streaming)?
6. what is more important: latency (reaction to first data) or bandwidth (kilobytes per second)?
7. what is the other device? did you design it? can it be modified if need be?

etc

Smile | :)

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

Local announcement (Antwerp region): Lange Wapper? Neen!

Re: serial port communication with multithreading

Md. Marufuzzaman13-Oct-09 6:02

Md. Marufuzzaman

13-Oct-09 6:02

This is nice I agreed.

Thanks
Md. Marufuzzaman

Don't forget to click [Vote] / [Good Answer] on the post(s) that helped you.

I will not say I have failed 1000 times; I will say that I have discovered 1000 ways that can cause failure – Thomas Edison.

Re: serial port communication with multithreading

Member 647306614-Oct-09 5:51

Member 6473066

14-Oct-09 5:51

I know that I asked same question that before 3 months ago but I tried to implement for it but still facing problem and dont know the solution. let me explain from scratch so you will have some idea about it.

1) My allication has to intract with another device and this device cannot be modified. Its kind of embedded tech. means whaterver signal the device can send that computer has to recieve it and in some cases computer has to send some instruction to control the device.(in the case when the device generates signals and if it goes beyong some set points then computer has to control it. its kind of two way communication).

2) its in format of binary of ascii value.

3) there is no minimum or maximum length. its continous

4)probably its real-time.

I dont have enough background info about this and I am only in this project so cant get help from other and never work any this kind of project in past.so please give me a proper guidence for it.
thank you so much for intrest in this topic.

thanks.

Re: serial port communication with multithreading

Luc Pattyn14-Oct-09 6:00

Luc Pattyn

14-Oct-09 6:00

that still is extremely vague.
what is the peripheral's function?
is the peripheral a commercial one, has it on-line documentation I could look at?
can you show say 100 bytes of the data, preferably in hex?
both continuous and real-time is something Windows cannot handle; maybe you're exagerating?

Confused | :confused:

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

Local announcement (Antwerp region): Lange Wapper? Neen!

Re: serial port communication with multithreading

Member 647306614-Oct-09 10:55

Member 6473066

14-Oct-09 10:55

means? I didnt understand what kind of details you want?
Actually I am going to use this programming for commericial use. In my project there is a need to develope this. the requirment is computer has to recieve signals from another device which is not computer but its a kind of detector. and whatever signals it sends computer has to recieve it.
still if you have confusion then let me know I'll explain you. If you are availabe for chat then we discuss about it more clearly.

but thanks a lot for help.

Re: serial port communication with multithreading

Luc Pattyn14-Oct-09 11:15

Luc Pattyn

14-Oct-09 11:15

I don't chat.
I have read your several messages and still have no clue about your app, your amount of data, its timing, etc.
You'll be on your own.

Hmmm | :|

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

Local announcement (Antwerp region): Lange Wapper? Neen!

MaskedTextBox mask problem

EnkelIk13-Oct-09 5:22

EnkelIk

13-Oct-09 5:22

Hi All!

I have a problem that I can't find the solution of:

In an application I'm using MaskedTextBox controls for dates (displaying current value and letting user change value). Default language for application is Swedish and mask is 0000-00-00 (for yyyy-MM-dd). This works fine.

The application is also to be run in Finnish and then I set the mask to 00.00.0000 (for dd.MM.yyyy), this does not work at all! The mask is correct but for a reason beyond my comprehension in the text-property of the control the "." (dot) is replaced with "," (comma). I have tried to replace the comma, to overwrite the text property and a number of other things but without success.

Is the problem that the control interpretes the date as a number and replaces the dot with the NumberGroupSeparator and NumberDecimalSeparator of the MaskedTextBox.Culture? If so how do I get the control so interprete the date as a date?

What can I do to make the MaskedTextBox to work with my Finnish dates???

Thanks!

Chris

Re: MaskedTextBox mask problem

dan!sh 13-Oct-09 5:33

dan!sh

13-Oct-09 5:33

I guess yes. It is picking things up from the current culture. I think you will need to override that through FormatProvider.

It's not necessary to be so stupid, either, but people manage it. - Christian Graus, 2009 AD

Re: MaskedTextBox mask problem

Alan N13-Oct-09 5:57

Alan N

13-Oct-09 5:57

Hi,
Have you read the MSDN notes for the Mask property? To me they suggest that the date separator / will be interpreted according FormatProvider.

Alan.

Re: MaskedTextBox mask problem

EnkelIk13-Oct-09 20:51

EnkelIk

13-Oct-09 20:51

Thank you Alan!

You've made the day for our whole project team! Smile | :)

/Chris

Codeproject forum ... ?

devboycpp13-Oct-09 5:18

devboycpp

13-Oct-09 5:18

You have seen the user comments part of the forum of the codeproject site. It is like a treeview control.
I have managed to make something similar to it. As you see in the forum a line is put after a message and all its answers. Can anyone give me details of how it is done ? What are the algorithm ,the database structure and details ?

Re: Codeproject forum ... ?

Md. Marufuzzaman13-Oct-09 5:53

Md. Marufuzzaman

13-Oct-09 5:53

Well... This is Gr8. I think you can write an article and post it at codeproject.com on what you did.. so we can also get some idea on it.. Thumbs Up | :thumbsup: