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I'm looking for ways get my app to wait until a network stream is fully returned. Unfourtunatly NNTP uses differant stream terminators for the output of each command (if any at all), and that makes this a little awkward. My VB app calls an NNTP server via the TCPClient and reads the response. Pretty standard you'd figure. I'm having trouble with the requests that return more than one line of data, however.
Basically it seems that my code is rushing to execute faster than the response comes in so the read loop is terminated because the netstream peek is empty. The response is still comming and if the app would wait a min, it would recieve the subsequent data.
When i step through (or even break for a sec) the code works fine, but if I run through it without breaks, it only reads the first line. Typically I use My.application.doEvents to address these issues in forms but the read code is in a backend classlib.
I've tried some simple threading algorithms (running on a sepperate thread that dosn't sleep, or pausing the main thread) but they don't seem to help either.
If anyone could point me in the right direction on this I'd be most appreciative.
TIA
Frank
hey...slang is the vernacular for the vernacular...wow
-- modified at 3:06 Monday 29th May, 2006
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I'd recommend a mixture of threads and delegates. First thing to do is spawn a new thread for your stream listener "master". The only purpose of this thread is to get it off of the main forms thread so the user will not see a performance hit when it does it's work.
Then, from that thread, you'll launch your additional threads. These threads should be spawned with a reference to a new instance of a class that handles all incoming events. Once that thread is running, it will send and receive all of the data relating to the newsgroup you connect it to.
Now for the delegates fun  . In each thread that spawns, you should have a delegate back to the main form that will allow you to update the users gui.
Now, for an explanation of why this will work. When you start the new thread with a socket it will stay open until you specifically close it or the other end closes it. If the other end closes it, it's because of a timeout issue. If a timeout issue occurs on their side then it won't matter because that is a true indication that you're not gonna get anything else from them. The delegate back to the main form will fire the event no matter what is going on. There's no need to set up a loop or anything to monitor. The rest of your code can do whatever it wants and it will fire that event whenever the new data is received.
Now, you seem like the kind of person who doesn't mind research, so here's a list of what to look for:
System.Threading.Thread (will launch the new thread)
Delegates
Sockets
A mixture of those three should give you what you need. Either that, or I'm loosing my mind and I'm just rambling on
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Using VB.Net - I have an Access database. I have created bindings for my textboxes including format and parse delegates. Will display the table fields just fine. Formats the data the way I want. Problem - addnew method does not work. Does not create a new record. Simply overwrites an existing one. What's the right way to add new records with formatted, databound text boxes? Is there an article or best tips you can suggest? I've already poured over this site for one.
Thanks in advance.
JDFA
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Access can be quirky especially with autonumbers so that may be where your issue is
also are you calling <newdatarow> = <datatable>.new<datatable>Row (for strong typped tables)
or <newdatarow> = <datatable>.Rows.newrow (for weak types)
(this gets an appropo autonumber and inits all feilds in the new row with default values)
Befor calling <datatable>.rows.add(<newdatarow>)?
make sure your not specifing the index that the row is added at. let the framework do that.
Hope that helps,
Frank
hey...slang is the vernacular for the vernacular...wow
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Thanks for getting back to me and giving me some things to think about.
I was using me.bindingcontext(<datasource>).addnew and got nowhere with it.
I also tried <dataset>.tables<"tablename">.addnew with no effect. It is an autonumbered table and I wasn't specifying the index. I take it that I want to create a new row, assign the values and then add it to the table.
Question - what is the parse function doing for me then? So far, it only seems to be affecting existing records that I want to edit. Part of my problem may be that I don't understand yet exactly how it is to be implemented.
Thanks a lot. Great site - Incredible info,generous experts.
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Look into Parse and Format.
You use those to modify the on the data in and the out for presentation and storage.
IE: you have a DB that some yahoo created a collumn with "y","Y","n", and "n" in it.
you want to bind it to a checkbox. if the feild was a bit/Boolean, you could directly bind it with the datasource property or by using
me.checkbox.databindings.add(new binding(me.dataset1.<tablename>, "<feildname>", "Checked <or any="" other="" bindable="" property="">"))
...or somthing a lot like that.
as an aside You can do really neat things with lookup tables and comboboxes with this command by binding the display(human readable text feild) and value(the pk feild) members oif the combobox to teh lookup table, and then binding the selectedvalue property to teh real datatables fk feild into the lookup table.
I can't quote you the code to parse (to morph data from the UI to fit the database) and format(for the data coming out of the dataset into the UI), 'casuse I design my databases with some forthought, but basically you create events for the feild parse and format, and within those, you mutate back and forth.
Below are some assorted ramblings with a tip or two buried within them, mainly on binding context and currencymanagers. it isn't directly in your question but if you like check it out.
within your binding context are all your datasiource objects (datasets, dataviews, and datatables) each instance of which has a currency manager that points to and iterates through the datarows within. Currency managers are Great but theres a gotcha. you only get one per instance of a datasourceobject. thats Why I create dataviews to show the datatables in my datasets when I'm binding them. also no more than one control can be bound to a feild on a particular datasourceobject. but you can have multible views sitting atop the same datatable and bind two controls to the same feild but on the other view.
AS a result I always get my currency managers by using
dim thing as CurrencyManager = ctype(me.bindingcontext("<datasourceobject>"),currencymanger)
whenever I need one (and you can just use the whole expression instead of )
Now there are some advanced members to this lib that intellisense won't point out to you by default. I recomend that you disable "Hide Advanced Members" in teht Visual Studio options. My favorite is
ctype(me.bindingcontext("<datasourceobject>"),currencymanger).current.row("<feildname>")
to access the value in a row. not nesecarily the best form but it gets the job done.
have fun,
Frank
hey...slang is the vernacular for the vernacular...wow
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hello
i want to disable only close button of the form and other two button should be enable please tell me how i can do this thing. plz tell me soon thanks
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btnClose.enabled = false
Roy.
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hi
try to use the closing event for your form
Private Sub Form1_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing<br />
e.Cancel() = True ' this will stop the form closing <br />
End Sub
Tamimi - Code
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HI guys, I'm a student and need some help with dates in VB.NET. What do I do to verify that date values are input correctly on a form? This includes the following: The day, month and year are entered separately; One cannot (obviously!) be born on day 0 of month 13, or on 29 February 2003. I've never worked with dates and don't know how to go about this. Can someone please help me here?
MichMar
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With the day, month and year being inserted separately ... it can be easy to check.
some normal logic
You will ask the year first because of leap years and stuff.
Next the month will be enetered in
if EnteredMonth > 0 and EnteredMonth < 13 then<br />
'month is a correct month<br />
else<br />
'month is not correct<br />
end if
then when u know the month you can demine if the month has 30/31/28 or 29 days and the day can be checked to see if it falls in the bounds
here is just a basic layout that you can change to suit your variables ect .. i think that more than explains it how i would go about it
<br />
if year = leapyear then<br />
<br />
<br />
else ' not a leap year<br />
if month = 4 or month = 6 the 'all the months that have 30 days<br />
if enteredday > 0 and enteredday < 31 then<br />
'date is correct<br />
else <br />
'error <br />
end if<br />
end if<br />
<br />
if month = 5 or month = 3 then 'all the months that have 31 days<br />
if enteredday > 0 and enteredday < 32 then<br />
'date is correct<br />
else <br />
'error <br />
end if<br />
<br />
if month = 2 then 'month is feburary<br />
end if<br />
<br />
end if<br />
<br />
end if
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use a datetimepicker control
GUERVEN
Truth or Consequence
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hi there, I wonder if someone know an easy way to tarnish a given rgb color. (decrease the saturation)
I can't find working convertion algorithms between RGB <-> HSL
thanks in advance for your help !
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Where did you look ? The one in the C# section in my article on HSL works fine.
Christian Graus - Microsoft MVP - C++
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hi Christian,
it's a nice source you provided
All I need is this, am I right ? :
HSL hsl = HSL.FromRGB(bytesSrc[2], bytesSrc[1], bytesSrc[0]);
hsl.Saturation *= factor;<br />
Color c = hsl.RGB;
Gonna try that ! thanks
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Yep, that looks right.
Christian Graus - Microsoft MVP - C++
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That works like a charm !!
I made a DLL with only your C# class HSL and then I typed this in VB.Net :
Dim dlg As New ColorDialog<br />
If dlg.ShowDialog() = DialogResult.OK Then<br />
Label1.BackColor = dlg.Color<br />
Dim theHsl As HSL.HSL = HSL.HSL.FromRGB(dlg.Color)<br />
theHsl.Saturation -= 0.6<br />
Label2.BackColor = Color.FromArgb(theHsl.RGB.ToArgb)<br />
End If
That's all I needed, problem solved !! thanks a lot
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Hello.
I writing some vb ( using vb 6 ) application and in some place i need to show some window on the top of all other windows.
The other windows are working in different application and i don't have any connection with them.
How can i be sure that my window in really will be on top ? i always find some place that the other window show their windows on me - so my window is not on top.
Thanks for any help.
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For the top of all window, You must open your window as modal window. In modal window, No window comes on top unless your window have been closed.
form1.show vbmodal
Kumar Prabhakar
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I'm using Nemanja's Task Pane project and I have all the panels laid out the way I need them and I'd like to add click events to the items in each panel. Could someone tell me or show me how to do this?
Thanks,
Andy
P.S. It's way too much code to post here and I don't see how to attach a file here, so here's the link to Nemanja's project. http://www.codeproject.com/useritems/TaskPane_Source_Works.asp[^]
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Hi,
I am developing a Multithreaded Application for Scanning using Black ICE Imaging SDK. In one Primary Thread I am scanning Images and saving them to collection. In Second Thread, I am doing Image processing on the scanned Image by taking it from Collection.
My Problem is the Primary thread is scanning Images, but in Secondary thread when I try to load it from temporary file or Collection, I am getting some Exceptions. The brief Code for this is given below:
Sub StartScan( )
BiTwain.Action = BITWAINLib.enumScanOperations.TWSTAT_BATCHSCAN
Dim thrd as Thread
Thrd=new Thread(AddressOf ProcessImage)
Thrs.Start()
End Sub
Sub BatchPageDone( )
BIDIBObj.SaveDIBInImageFormatExt("C:\Temp\” & TempCount & “.tif", hDib, 1,
BIDIBLib.enumFileFormats.imgffTiff,
BIDIBLib.enumCompressionModes.imgcmCcittG4, BIDIBLib.enumFillOrderModes.imgfoNormal,
False)
TempCollection.Add(("C:\Temp\” & TempCount & “.tif")
End Sub
Sub ProcessImage( )
While TempCollection.Count = 0
Thread.CurrentThread.Sleep(100)
End While
'Loading Image to Memory
'I am geting error at this point
Hdib=BITiffobj.LoadTiffIntoDIB(TempCollection.Item(0).ToString(), 0, False)
'Processing HDib
End Sub
When the Secondary thread try to Load the Image from file, I am getting two errors. While trying to load First time, the Exception is “Request Timed out”. When try to load second time, the exception is “Because this evaluation could cause side effects, it will not be executed until enabled by user.”
Thanx,
.Net Programmer, Software Engineer
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Dim thrd as Thread
Thrd=new Thread(AddressOf ProcessImage)
Thrs.Start()
Is this your actual code? Should be Thrd.Start() instead of Thrs.Start()
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Sorry, It's a typing mistake.
It is Thrd.Start()
.Net Programmer, Software Engineer
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Visual Basic 2005 Express Edition:
This works, but, I need to get the .wav file from Resources:
My.Computer.Audio.Play("C:\Documents and Settings\Owner\My Documents\Visual Studio 2005\Projects\OrthoLabRx\OrthoLabRx\Resources\PodVwBy.wav")
I placed the .wav file in Resources, but, I can't seem to access it from there.
This does not work:
My.Computer.Audio.Play(My.Resources.PodVwBy)
It says "value of type 'System.IO.UnmangedMemoryStream' cannot be converted to 'String'.
This worked, but, instead of a click, it played a grinding noise:
Dim sndPing As New SoundPlayer(My.Resources.PodVwBy)
sndPing.Play()
My.Computer.Audio.Play(My.Resources.PodVwBy)
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I have an application that I wrote that causes a variety of message boxes to come up. Can somone here help me with how to make the message box color change.
Thanks
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