UDP Class With Time-out?
Aug 29, 2005
The trouble with the UDPClient class in .NET Microsoft, in its infinite wisdom, built this class in .NET as a simplified method for UDP communication. The one critical thing they forgot to include was a simple time-out feature.What's wrong with not having a time-out? Plenty, if you have one end of the transmission expecting to receive data, and the source of the transmission decided to go belly-up. If you use the UDPClient.Receive method, and the application sending the message does not send the message, then that UDPClient.Receive method will block forever--at least until the application is closed by the user.
A rather nasty way of handling such a situation. By the very nature of UDP, packets can get lost and never be received, causing the application to wait forever, or a bug in the sending application may simply cause it to never send the message that is expected.
Why on earth Microsoft did not put a time-out feature in this class is beyond me. What this means is that if you are doing any real programming you'll find the UDPClient class to be hopelessly inadequate. You'll have to instead use the more generic Socket Class to accomplish your task.
Below is a code sample that uses the Socket Class to accomplish the tasks that the UDPClient is meant to do, but with a timeout.The UDPClient Class is for synchronized data transmission. If you are trying to do asynchronized transmission, you would have had to use the Socket class, anyhow.
Code:Imports System.Net.Sockets
Protected Shared Function UDPDataTransmit( _ ByVal sBuff() As Byte, ByRef rBuff() As Byte, _ ByVal IP As String, ByVal Port As Integer) As Integer 'Returns # bytes received Dim retstat As Integer Dim Sck As Sockets.Socket Dim Due As DateTime Dim Encrp As IPEndPoint Try Sck = New Socket(AddressFamily.InterNetwork, SocketType.Dgram,
[code]....
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Apr 8, 2011
I want to have my main class for creating activity for 2 different flags.
1) One with relative layout Textview and images for which I am extending my class as[code]...
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Jun 9, 2011
I'm having trouble with a Stopwatch one one of the user's machines. I'm using the Stopwatch class to track time elapsed on one of my applications, and it seems to work fine on everyone else's machine, but on one machine it goes really slow. It's probably 1/3 or 1/4 of the actual time elapsed.
Here's the
I'm using the timer to update the textbox that displays the time elapsed of the stopwatch every second.
Partial Public Class
Private WithEvents breakTimer As New Timer
Private breakSW As New Stopwatch
[Code]....
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Aug 2, 2010
Let say I have a function inside a class which require 4 parameter (table name,field name,field value, return field) When I use this function my form, such as
myclass.Search("customers", <-- after pressing the "," a popup list will be displayed that contain all the fields in "customers" table.
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Sep 6, 2009
I have an ASP.NET application with a SQL Server back end. I am storing all my dates in UTC format and doing the appropriate conversions to the local time zone of the browser viewing it. One of the pages asks for a start date and end date (no times).
I am taking the start date and setting the time to 00:00:00 hours (midnight) and I'm taking the End time and adding a time of 23:59:59, so that the date range covers the whole day. Now what I'm trying to do is do a SQL query to do a search for records in this date range. The problem is, the data in SQL is in UTC time and the user is typing their dates and times in their local date and times. My quickest solution was to convert the date and time to UTC, then search the records. However, by doing this, I am to believe ASP.NET converts the given time and date to UTC based on the server time zone. How can I convert a date and time to UTC time based on the time zone of the user?
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Dec 16, 2009
If Class X is within the scope of Class Y, is X a subclass of Y?If Class A is a sub Class of B, then is Class B considered a super class of A?if Class C inherits Class D is Class D a superclass or parent of Class C?if Class E extends Class F then we can consider Class E a child of F?if Class G inherits Class H and is within the scope of Class I then who is the parent of Class G? Classes that inherits Class J and classes that are within Class J are all sub classes of Class J?
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Nov 10, 2011
Dim box As MultiTextBox = New MultiTextBox
Dim i As Integer
for i = 1 to 3 Step 1
lengthWidthHeight = MultiTextBox.GetItemValues()
Next i
This excerpt of code is using the NXOpen API. In the NXOpen API, the MultiTextBox class is public. However, when I compile the code I get the message:
'NXOpen.UIStyler.MultiTextBox.Protected Sub New(ptr As System.IntPtr)' is not accessible >in this context because it is 'Protected'
My question is, how am I getting an error about protected scope? Could it also be that the API documentation is incorrect?
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Apr 15, 2010
I have put this code in the global form Inherits System.Windows.Forms.Form. And then in the form that will inherit this from the global Inherits MenuStrip. "MenuStrip" is what the global form is called. But keep getting this error: Error1Base class 'MenuStrip' specified for class 'Lesson2' cannot be different from the base class 'System.Windows.Forms.Form' of one of its other partial types.
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Jul 22, 2011
I have a class (see below)
Imports Microsoft.VisualBasic
Imports System.Data.SqlClient
Public Class ClientProfile
#Region "Variables"
[CODE]...
It is in the file ClientProfile I have placed in both App_Code and also App_Code/Models
In my code behind I have the following
[CODE]...
The last word, "ClientProfile" has the scary squiggly red line below it. It is not recognizing my class.Even the Intellisense is not picking up te class. Do I have to register the class file in any way?
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Sep 11, 2009
Dim a as Type=GetType(className) would gimme the type. But I have only the name of the class as string. I want something like GetType("class1") which would return the type.
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Aug 1, 2011
spell check class? How to use it to spell check textboxes in real time?
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May 15, 2009
I can't make difference between public class and private class and friend and protected friend class.
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Jan 21, 2010
I can do this without problem.
Class A
End Class
Class B : Inherit A
End Class
Dim Obj1 As A = New B
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Aug 9, 2011
so I used to mess around with C#, just a little. And someone had helped me make a class for Visual C# that was supposed to do the math parts for "internal structure" - which the program used for a part of its calculations and screen... Basically there were 2 options. Endo-Steel and Standard. The user would use a updownbox to determine weight of the machine and then internal structure was a % of that total. If it was standard then it was 10% of the overall weight, if it was Endo-Steel then it was 50% of standard (so 5% of total weight) rounded to next 0.5 (so .25 was .5, 1.25 was 1.5, 1.75 was 2.0, etc). I have the code for the C# class file for it, but want to make it in VB.
[Code]...
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Jun 22, 2010
The idea with this form is to add the futures which is calculated when the button is pushed but I need the list to update every time and show the values each time to which the previous value is added to the new calculation, e.g. of what it should look like in listbox:
Year 1: $1,290.93
Year 2: $2,724.32
Year 3: $4,350.76
etc....
I have been working on this a while and I am at a standstill, I was given a function to clear the form everytime it calculates but I don't know how to implement it, I am new to VB. Here is what I have so far:
Public Class frmFutureValue
Private Sub btnCalculate_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnCalculate.Click
[code]....
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Nov 13, 2010
Basically i'm trying making a task manager program for myself. I want to know how I can display a message box and or play a sound when system time = time displayed in listview. I have used a dropdown box for the user to select which option they would like to select - sound or message box to popup. The data for the task will be stored in a listview box. I want it so that when the date and the time is = to the date and time set for the reminder the action will follow.Here is my code so far:
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim notext As String = ""
If TextBox1.Text = notext Then[code]....
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Jul 22, 2011
So I currently have the following:
2 timers
2 labels
1st label is "Clock" this pulls the time from the users current time zone/local time
2nd label is "UTCClock" Which would be UTC time
Now I have this for the first label: clock.Text = Format(TimeOfDay, "hh:mm:ss tt")
Which would give the users current time zone/local time. As for the UTC.. how would I add in for the UTC time from where the user is located at? I did some searches.. but couldnt find what I was looking for.. IM pretty sure its not as easy as getting the users current time zone/local time.. So im assuming that Theres a "bit more" code into getting UTC time..
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Jan 24, 2012
I'm using
Days = Dat2.Subtract(Dat1).Days
where
Dat2 = today
Dat1 = installed date
to trace the days of a program installed in user's computer.However, the user can changes the system time of his computer to a advancing date. How can I get a SNTP time from internet to solve this problem?
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May 3, 2009
I need a start date, a Total time passed until now, an average time per step, and a estimated time to finished. How can I do that? Also, I can close the application and when start up again I want to get the time counters as the last time, so How can I store that data is normal txt file (I say txt to take advantage of the ini app file which is a txt).
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Aug 24, 2010
I am using this line of code on form load event it is working very fine but i have to problems
1. It replaces the form name and display the date and time but i want to keep both date and time and forms caption separated by some space.
2. When form loads it load the current date and time but the time does not change it should run.
What should i do please please help me code is as follows
Me.Text = Date.Now.ToLongDateString & " - " & TimeOfDay
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Aug 24, 2011
I used .NET Framework 1.1 in C/S project before. Now I have updated the project to use .NET Framework 3.5 without modifying source code, but I have found that : the Remoted DateTime values can not be converted to the equivalent local time of a remote computer that is in a different time zone. In .NET Framework 1.1, the DateTime values can be converted automatically.
[Code]...
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Apr 19, 2012
There is a varchar column in the database table in this format of military time 1230 or 1750 or 1320 and that field get populated into a gridview in asp. I need to convert that string to standard time. I have tried the DateFormatString and nothing seems to work.
the asp is
<asp:BoundColumn DataField="ScanTime" SortExpression="ScanTime" ReadOnly="True"
HeaderText="Scan Time" DataFormatString="{0:hh}:{0:mm} {tt}">
<ItemStyle Width="80px"></ItemStyle>
</asp:BoundColumn>
that DateFormatString causes Input string was not in a correct format. error.
I have tried combinations of hh:mm and things like that but since its a varchar I think its failing
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Dec 6, 2010
How to get the current date and time in textbox in IST ( Indian Standard Time) in vb.net ?
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Jan 1, 2010
at the time of recoredset movenext out of memory error occured in run time data have 3800000 lakh recored
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Dec 18, 2010
Is there a way of converting a unix time stamp to normal format time and date in .NET?
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Jan 30, 2009
using VS2008, targetting framework 3.5I have a rather complex UserConrol which does some of its own rendering.I display this UserControl on a form.Opening that form in the Designer creates an instance of the UserControl in the Designer, which tells me a NullReferenceException is occurring in one of my rendering methods.I have attempted to correct this by making alterations to the UserControl's default constructor, but have not found success.
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Jun 9, 2011
Just getting started in VB.NET. I would like to add X-number of text boxes at run time. And then be able to address them by their index or some sequential numerical value (like an array)
This is what I have so far:
CODE:
When I turn this into a loop to create multiple toolboxes, how do I assign a name to the controls, or will all of them be named "MyTextBox" ? I'll increment their position so thats no problem.
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Mar 19, 2012
When I run my app at first its keeps time accurately for the first minute or so there after it starts loosing seconds, and by the end of the day its minutes behind.I've created a class called ServerTimeTimer that has a timers.timer object that elapses every second and adds a second to a dateTime variable, and a property to retrieve the date time.[code]
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Dec 23, 2010
i'm using a date time picker with format set to time. i want to be able to trigger an event at the time selected in the date time picker
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Feb 10, 2012
I have a program that reads a file with Pacific Daylight Time, I want users to see the time and date in their local environment.
At present I have in Australia a time difference of 18 hours, so I have a list box with -24 to +24 and currently set at 18, my code is elementary as long as I have moved past day one of the month it suits me personally, but I want to distribute my app, so I need something better.
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