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I have a question
I dont know if anyone here is familiar with the zedgraph API but its pretty cool.
http://zedgraph.sourceforge.net/[^]
I am having issues here tho.
I want to create a live moving chart that updates in front of your eyes every single second.
Stock Market Chart -- candlestick, bar chart, etc.
When i start my program i draw the graph but i do not populate it with data yet.
I then made a button that when it is pressed it will get the data feed and start populating the
graph chart. Here is the problem!!!!
When the data comes in my app just freezes!!! (in the background it's just constantly reading in the data not drawing or updated the chart at all)
So then i said okay let me just use a small amount of data.
When i clicked the button with a small amount of data it did absolutely nothing.
But when i minimized my application down to the windows taskbar or toolbar
(or whatever its called)
and then maximized it (brought it back up and to focus) The chart was populated and everything looked great.
I guess my question is why did i have to minimize it and then maximize it to see the results of the drawing of bars on the graph.
And why cant i see my data update and draw right in front of my eyes!!!
Thanks in advance to anyone who can help me....
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How and when are you painting?, show your method.
Are you calling your paint method on each pass?
Are you double buffering your graphics?
Are you looping through your data first, then painting or are you painting on every loop of data?
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I believe you need to refresh your form/chart every time you want to update the chart. You said every second. I would try a timer and the tick event, refresh your form.
jude
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Refreshing the form was exactly what i needed to do.
Thanks alot.
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Happy I could help!
Happy Coding!
jude
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I have written a Windows Service application in C# that works and is controlled by a separate C# tray application. The service queues up and processes a list of files from a specified directory. I would like to be able to get the current list on a regular basis using a timer from the tray application so I can report to the user the current processing status. I know that I can override the OnCustomCommand method in my service and call that through a servicecontroller on the tray app, however, this method returns void so I can't use it to get back the list currently being processed. Does anyone know if there is a simple way I can share data between the two applications?
Thanks.
-Matt
------------------------------------------
The 3 great virtues of a programmer:
Laziness, Impatience, and Hubris.
--Larry Wall
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perlmunger wrote: The service queues up and processes a list of files
If the processing occurs at sufficiently large time intervals, perhaps the service could keep its last valid status in a file known to the tray app?
/ravi
My new year's resolution: 2048 x 1536
Home | Music | Articles | Freeware | Trips
ravib(at)ravib(dot)com
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Ravi,
Thanks for the suggestion. I've thought of that and will implement it if need be, however, I was hoping to avoid any IO (disk or otherwise). Even if I could just pass a long comma-delimited string between processes it would be nice. I don't need it to pass some complex data type.
Thanks again.
-Matt
------------------------------------------
The 3 great virtues of a programmer:
Laziness, Impatience, and Hubris.
--Larry Wall
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OnCustomCommand is very limited. If you want more functionality you need to use IPC ( InterProcess Communication ). I suggest you have a look at remoting.
----------------------------
Be excellent to each other 
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I really dont know networking.
Why every LinkSYs router has such IP:
192.168.1.1.
I am confused, if router has this IP, how can an packet know where to go?
I know this must be a stupid question....Dont laught at me
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This is not a C# question...
But I will supply you with an answer : the router usualy gets the IP addres 192.168.1.1. Why this addres? Maybe because this is an easy-to-remember addres. Anyway,I know thatthe addrescan be changed.
A packet travels through the internet with the help of gateways. A gateway routes the pachet to the requested destination.
This is exactly what a router does : it has 2 port types - LAN and WAN. It routes the pachets from the lan to the wan and viceversa, it acts like a gateway at a specified addres.
protected internal static readonly ... and I wish the list could continue ...
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192.168.1.1 is the first IP address in a class C private network. Read this RFC for more information about private networks: http://www.ietf.org/rfc/rfc1918.txt[^]
-Matt
------------------------------------------
The 3 great virtues of a programmer:
Laziness, Impatience, and Hubris.
--Larry Wall
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LinkSys routers have 192.168.1.1 as an ipaddress because
LinkSys assumes you will be communicating on this already configured subnet.
Subnet address --> (192.168.1) Host --> .1
Note:
The .1 in the ipaddress represents the router, 192.168.1 represents the subnet.
I wont mention the subnet Mask, this only will confuse you further, you must first understand the basics.
For example if you are at home and use DSL or Cable for internet access.
You have a modem which connects to your LinkSys router. Your router actually has 2 IP addresses
69.254.36.244 or whatever for your external (public, internet, WAN) address and 192.168.1.1 for your internal (private, LAN) address.
If your router is configured as a DHCP server (The duty of passing out ipaddresses to anyone on your private network) Then every computer connected on your LAN or private network will receive an ipaddress on the 192.168.1 subnet from your router.
So whenever you connect your computer to your linksys router you will receive an ipadress between
192.168.1.2 - 192.168.1.254 - remember 192.168.1.1 is used for your router so u cant use that one.
Hope this helps
If a router has that particular ip (192.168.1.1) then how does it no where to send packets???
Easy!!!
The packet will either have an IP address on the subnet configured by your router (192.168.1)
or some other IP address not on your private Network!!!
If the packet has an ipaddress on the 192.168.1 network (subnet) it's communicating on the LAN so it will send the packet to another computer on the subnet.
If it has a weird 68.126.88.92 ip address on the packet then it will send the packet out to the external IP address - Then your packet will be in the hands of an ISP router.
Then that router looks to see if it has the direct destination of the packet on its network if it doesnt This router also has another ip address so it sends the packet away to another router and so on and so on until it finally reaches its destination!!!
-- modified at 18:13 Friday 10th February, 2006
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OK, i'm building an application where a user will be required to enter customer data which will later be stored in a database.
As an example, the user may have to enter the customers email address into a text box.
Now obviously, there has to be some kind of validation between the data being entered in the UI and stored in the database not only to avoid sql injection but also to check the format etc.
My question is where the validation should occur?
Should there be an emailAddress object which performs such validation?
It doesn't seem the right approach to attach all the validation to the UI.
Regards
Wayne Phipps
____________
Time is the greatest teacher... unfortunately, it kills all of its students
View my Blog
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You didn't specify whether this was a web app or a winforms app. The answer is different depending on that. In a web application, the answer is it should be done on both the UI *and* on the server side. This is because it is possible to circumvent form controls by writing automation scripts that ignore UI validation. You should be validating on both ends--on the client side to provide quick feedback to the user without a round-trip to the server, and on the back end in case something slipped past the client validation.
If, however, you are building a winforms application, it depends on how much detail you give to your design. Good multi-tier design might have you place validation in a business rule, however, there is virtually no danger that the user will hijack the request in a winforms app which means you could validate once on the control and not have to worry about getting bad data.
Anyhow, a google search will provide you with a lot of information on how to validate user data using C#.
-Matt
------------------------------------------
The 3 great virtues of a programmer:
Laziness, Impatience, and Hubris.
--Larry Wall
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Initially, the app will be winforms based with a view to adding a web based customer portal further into the project.
My reason for asking these questions now is an attempt to avoid hard coding potential problems into the design but I also have a desire to keep this as simple as possible.
Regards
Wayne Phipps
____________
Time is the greatest teacher... unfortunately, it kills all of its students
View my Blog
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Items like this don't, in my experience, create major design issues. Larger business rules such as (and I'm making this up) "Child record can only be entered if Parent record field 'hasChild' is checked" tend to be what cause more problems from a design perspective if you hard code them. You might later decide you want to determine whether a parent has a child based on whether or not there are actually any child records related to a parent record, so such a validation would be done more at the database level (I hope I'm not being to obscure here).
Simple "sanity checking", so to speak, won't create major design flaws that will cause you to have to start over. You might have to tweak the patterns you are using, but there is not a lot of danger in doing so and will in all liklihood be necessary. In practice I almost always just add the basic validation to both the client and server (or just the form in winforms) without providing some larger design structure for it. That's me though. I'm sure there are other opinions. 
-Matt
------------------------------------------
The 3 great virtues of a programmer:
Laziness, Impatience, and Hubris.
--Larry Wall
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i am trying to build a "missed message" queue on a C# TCP server. many
of the devices connecting are mobile and may drop out in bad signal
areas. i want to store any messages missed for when they reconnect.
so far....it takes activity on the client end to initialize the close.
isnt there a check when the server sends a socket.send to a client that
has lost connection? it takes a few minutes for the exception to get
hit, and i am losing vital time.
is there a way for as soon as the the server attempts Socket.Send it
can tell if the device on the other end still has an active connection?
even Socket.Poll() has quite a delay.
i have been testing with desktops. I connect two workstations to the
server and when i chat back and forth, i unplug one from the network.
it takes at least two minutes for the server to recognize that one
client is disconnected while the still-connected client is sending
messages. it seems they are just going nowhere.
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How about using UDP in some way?, it is a connectionless protocol.
Packages like Symantec pcAnywhere (a remote control/file transfer application) use UDP to moniter the status between connections and TCP for data transfer.
Or alternatively, how about the clients collecting/pulling the messages from the server instead of them being sent/pushed to the client?
Just some ideas.
Regards
Wayne Phipps
____________
Time is the greatest teacher... unfortunately, it kills all of its students
View my Blog
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i thought UDP doesn't have verification of message arrival. it just sends blindly, right?
the problem with the client pull is that in my scenario, the clients are passive, the server handles all activity...sometimes automatically based on outside forces.
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<quote>it just sends blindly, right?
Yes, thats right. What I was thinking was perhaps the Client could send a UDP datagram to the Server at regular intervals. The Server could listen for the datagram, rather like pinging the server. The server need not send a reply to the client but upon receiving the request, it knows the client is still active.
It could keep the connection alive.
I guess however, it depends on how passive the clients are?
Regards
Wayne Phipps
____________
Time is the greatest teacher... unfortunately, it kills all of its students
View my Blog
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okay, i'm kind-a new in here, but i have a problem.
the problem is in my webservice, but this is in C#, and the problem is more C# related.
the code below is the code i use, it always return false through the Catch, the Catch sais "No Value given for one or more..." (well i hope you know this exception).
the problem i can't figure out, is why?
if someone can help me i would be very thankful.
yours, NaNg.
<br />
[WebMethod]<br />
public bool AddProject(string ProjName, string ProjID)<br />
{<br />
try<br />
{<br />
objCon.Open();<br />
DataSet ds = new DataSet();<br />
objDA = new OleDbDataAdapter(string.Format("Select Count([SID]) from tblProjects Where SPorjID = '{0}' And SProjName = '{1}'", ProjID, ProjName), objCon);<br />
objDA.Fill(ds, "tblProjects");<br />
if ((int)ds.Tables[0].Rows[0][0] == 0)<br />
{<br />
objCmd = new OleDbCommand(string.Format("Insert into tblProjects(SProjID, SProjName) Values('{0}', '{1}')", ProjID, ProjName), objCon);<br />
objCmd.ExecuteNonQuery();<br />
return true;<br />
}<br />
else<br />
return false;<br />
}<br />
catch (Exception exp)<br />
{<br />
return false;<br />
}<br />
finally<br />
{<br />
objCon.Close();<br />
}<br />
}<br />
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NaNg15241 wrote: the Catch sais "No Value given for one or more..." (well i hope you know this exception).
Um, no. This is pretty much the crux of your problem. You need to provide the complete text of the exception for anyone to be able to help you?
-Matt
------------------------------------------
The 3 great virtues of a programmer:
Laziness, Impatience, and Hubris.
--Larry Wall
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Hi,
I am encountering problems with clearing the combobox, the first value gets automatically selected. Even though i have set the SelectedIndex to -1 in the load event.
Another problem: I have placed the combobox on a tabpage of a tabcontrol. If I clear the combobox and then swtich tabs the first value again gets automatically selected.
The combobox is bound to string array.
Using .NET v1
It seems like a .NET bug to me. Any help would be appreciated.
Thanks.
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If you haven't already created one, add an event handler to the combobox for SelectedIndexChanged. Then add some dummy code at the beginning of that method and place a break point on the dummy code. Then, when the index changes, the break point will be hit and you can track where it was called from.
Hope that helps.
-Matt
------------------------------------------
The 3 great virtues of a programmer:
Laziness, Impatience, and Hubris.
--Larry Wall
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