i'm using the AppendText(serialPort.ReadExisting) method of the SerialPort class. i'm sending to the serial port a 12 byte frame. however in the TextBox control streams printed seem choppy as if the ReadExisting method is exiting too quick to grab all 12 bytes so i can display them at once.
View 3 RepliesI'm using the following to read a serial port. When run it displays the data correctly but stepping through the program I find that it loops through the serialdatarecieved event for each character of the port input rather than reading all of it. So _msg only equals one letter at a time. I'm trying to set a variable equal to the entire input stream but only get one character of it.The end goal is to capture all of the data available on the port when the event triggers so that this data can then be processed. I tried using the bytestoread function, which gets the correct number of bytes to read, and then looped through to read a byte at a time but that didn't seem to work as I expected either. It just kept reading the first byte.
Imports System.IO.Ports
Public Class CommTest
Dim WithEvents SerialPort As New SerialPort
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I'm trying to make a simple Class that reads data from a SerialPort.The Device returns a number of lines of Strings.
Code:Public Class Device
Private Device As New IO.Ports.SerialPort("COM4", 4800) Private WithEvents tmr As New Timer Public Event GotData(ByVal Data As String)
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i try readexisting and instr function as follow:
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Recently we have connected one bluetooth device which receive data from our serial device. The bluetooth device further transmite this data to a Windows Mobile which is bluetooth enable. Baud rate of whole system is 19200 with 7 data bit and 1 stop bit.When we send command to serial device through bluetooth device it is accepting the command and respond accordingly. but some of data byte of string is desplay as question mark (?).But in case we connect the serial device directly to PC, the string received is correct.[code]Response given by Serial Port is "?09?D03?A D?
View 1 RepliesRecently we have connected one bluetooth device which receive data from our serial device. The bluetooth device further transmite this data to a Windows Mobile which is bluetooth enable. Baud rate of whole system is 19200 with 7 data bit and 1 stop bit.When we send command to serial device through bluetooth device it is accepting the command and respond accordingly. but some of data byte of string is desplay as question mark (?).[code]...
View 4 Repliespeoples The User of my application will enter Hexa values in text boxes (00h to FFh). I need to send these values through the serial port, but so that EACH text box with values 00h to FFh ONLY generate ONE transmitted byte, exactly the value placed in the text box.
Just found examples of this application in VB6, using the following command:
MSComm1.Output = (Chr(Val(txtText1.Text)))
In VB2008, you use the component "SerialPort", and one of the methods for transmitting data to the output buffer is "Write". So I did it this way:Dim As Integer ValHex
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I have a filled dataset from a query.
I must modify 2 columns in this dataset, based on a custom function value (a normal vb function), which parameter is an another column from the dataset.[code]...
I have a program that is hooked to an external device via rs232. I can send and receive messages to this device just fine using the ReadLine() method of the serial port. This allows me to send a command and wait for a response in a synchronous manner. However, when I start the program I need to check the status of the device. If the device is in a sleep state, off, or on, I send a command and get a response, however, if the machine is unplugged, I get nothing so my program will hang waiting for a response before continuing. I would like to abort the readline after 1 minute and display a message that the external device is not connected or having a problem, etc. and allow the program to load. The command I use to check the device is:
Do Until Mid(balanceStatus, 1,3) = "S S" 'This is the return command that the status is read
spBlance.Writeline ("S")
balanceStatus = spBalance.Readline 'This will cause the program to hang if the external device is unavailable[code]....
That readline is causing the program to hang. So I need a way to abort if it exceeds a certain time (around 1 minute). I was trying to use the DataReceived Event of the serial port, but I need to wait for a response before continuing and DataReceived fires on its own thread.If there is a way to abort the thread, I was thinking of doing a timer control.
I am developing a VB application using the Visual Studio 2008 IDE. I was making changes to my code using the Quick Replace function when the dialog window stopped displaying. Selection of Quick Find or Quick Replace from the Edit menu, as well as use of shortcut keys (CTL+F and CTL+H) all have the same affect: the IDE loses focus but no dialog windows display. Is this a known issue with an available fix?
View 1 RepliesI am using vb2008.net express,I test vs2005term it work, can any tell me what is the input variable and output variable of this terminal?how to catch the input and output variable to a textbox1 for sending and a textbox2 for receiving when I press send button? is that possible?
View 1 RepliesI am getting two errors for "expression is not an array or method, and cannot have an argument list," When debugging, the formula works quite well. However I will lose points for blue squiggly lines. I am not allowed to use any built in functions like math.
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I want to allow my user to add urls to a database, much as a user might add file names. I have a form with a label, a textbox, and a browse button. I would like the browse button to load the user's default browser and then have the final url appear in the textbox when the browser closes. I have not been able to do that, but I have come close. I have not found a way to capture the url from an arbitray browser, so I instead load ie.exe and then capture the url with an OnQuit handler. That works (even verified by the debugger) but I am unable to get the url to appear in the textbox without actually clicking in the textbox once ie closes. I would like a suggestion as to how to avoid making my user click in the textbox and, if possible, to load the user's default browser and still capture the url. Here is my code for the Browse button (IE is defined at the class level as Dim WithEvents IE As SHDocVw.InternetExplorer):
theURL = ""
IE = New SHDocVw.InternetExplorer
AddHandler IE.OnQuit, AddressOf HandleIEQuit
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I am using VB.net and Sql server 2005.
I have GridView in Application where I have my CPUserID. There can be thousands records in GridView with different CPUserIDs.
Now I have a button "Allocate Token". But before allocating the token I want to check in my Token Table that if that CPUserID has already exists in table it should not allow user to allocate token and will return some message for that user.
For Each curRow As GridViewRow In GridView1.Rows
Dim cpuserid As Label = CType(curRow.Cells(1).FindControl("lblCPUserID"), Label)
Next
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I have been using the 'findby' method for sometime, but now it suddenly is failing me on a new data source I have added to the project. I have the data source bound to a form and I am trying to find values based upon a primary key. This evades me, I am able to look up rows using 'findby' with other tables, but not this one.
Dim AnsiX12Row As ansisupplementDataSet.ANSIX12Row = Me.AnsisupplementDataSet.ANSIX12.FindBySegmentElement(CurColName)
If AnsiX12Row IsNot Nothing Then
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I have checked and re-checked, the CurColName is for a value in the table, but cant seem to find it... I always have AnsiX12Row = nothingBradford W Brown
I have just converting my VB6 project to VB.NET 2008. I have set up start with Model. It start with Main() sub, in Main sub I have declare as below:
Dim frm as new Formpwd
frm.show()
In formpwd I have UserId, PWD as test box and Two command buttons. The system executes form_load code and then PWD and UserId_Gotfoucus handler and then closes the system. Why is not waiting to accept UserId and PWD?
I've made an application in Visual Basics, But I Want A msgbox to appear when the form is closed would this work?
Private Sub Form1_OnExit(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.OnExit
MsgBox("Have You Saved, If Not Your Work WILL Be Discarded!", MsgBoxStyle.Critical, "Have You Saved?")
End Sub
I created a game in visual basic. When the user answers correctly, a message box will appear and ask if they would like to play again. How would I get the program to exit when they push "No" . . .
Public Class Form1
Dim temp As String
Private Sub RadioButton7_CheckedChanged(ByVal sender As System.Object, ByVal e As
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I need to preserve a collection even after application exits. In ASP if i use application object this can be acheived. But in windows application what could i do to preserve collections?
View 4 RepliesIm working on a silverlight application where a user can create, edit, delete objects. The changes they make are placed in a queue which is processed every 4 minutes. When it is processed, the updates are sent over an async web method call to be saved in a sql database, one at a time. When the first update finishes, the next starts.Im having a problem when a user makes a change and then exits the browser app before the 4 minute timer has expired.Currently the changes are getting lost.Ive built on what the guy working on this before me has done, and explored the Dispose and Finalize methods, trying to start the update process when the factory is being shut down, but that isnt working due to the async nature of the web service calls. I get errors saying needed objects have already been disposed of.
View 1 RepliesI have developed a vb.net application which gets a folder as input with n number of .txt.When there are say 5 .txt files the application executes and produces the excel output.When there a n numpber of .txt files say 30, the application takes a long time and exits without producing the output.
View 29 RepliesI had originally saved the project I was working on to my desktop, but now I have moved the folder to another location on my hard drive (didn't want it on my desktop anymore).
But since I've moved it I get the message:
The working directory does not exist: 'C:old folder locationResources'.
Is there a simple way to update my project to the new folder location?
I'm running a bunch of automated tasks in a thread I'm creating via the Thread class. So I'm not using a BackgroundWorker.
During parts of the automation, the thread may exit. This is normal. But when the thread completes, I need to finish up some additional tasks. I can anticipate all of the conditions in which the thread closes, but I'd rather not to do the final tasks at each point, as this will create a lot of redundant code.
So instead, I wanted to write an event that is triggered when the thread exits. I looked through the Thread class, but all I could find was the ThreadState property, which has a Stopped property. But, when I try to add a handler to that property, it doesn't allow me.
For some reason, the next code found on MSDN crashes or exits after 30 cycles or, in other words, after processing 30th Property, exits without explanation. As I said, I found it in MSDN
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Consider a MyForm class that contains a shadowed implementation of Show(). It also contains a CreateForm() method, which accepts an instance of the form and calls the shadowed sub:
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how can i check if the file exist in the absolute path. for example i have images in the absolute path from which i have to check if the image exits I can do it from FILE.EXIST(path)this method is not working for absolute path, even if the file exits its is showing the file doesnt exist.
View 3 RepliesI'm designing a Windows Forms Application, and there is a dialog that should NOT exit when the enter key is pressed, instead it has to validate data first, in case enter was pressed after changing the text of a ComboBox. I've tried by telling it what to do on KeyPress event of the ComboBox if e is the Enter key:
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But no success so far. When the Enter key is pressed, even with the ComboBox on focus, the whole dialog is closed, returning to the previous form. The validation is NOT done at all, and it has to be done before exiting. In fact, I don't even want to exit on the form's enter KeyPress, the only purpose of the enter key on the whole dialog is to validate the ComboBox (but only when in focus, for the sake of an intuitive UI). I've also tried appending the validation to the KeyPress event of the whole dialog's form, if the key is Enter. NO SUCCESS! It's like my code wasn't there at all.
What is the best method to do data validation? I want to do data validation when the user exits a control so that he gets immediate feedback. I can use the Validating event or the Leave event for that. The problem is, that if the user doesn't know the right answer, and just wants to click the cancel button and leave the form completely, it won't let him. It continues to give him an error message until he completely deletes his answer. Very frustrating. Does anyone have a good method for doing this?
View 5 RepliesWindows Forms VB Application.. I added a splashScreen to my application. And it was flashing only for a second then going away so I added a sleep timer to my Form Load event... The problem is now the splashScreen stays open even After Application exits, instead of simply closing at the end of the sleeptimer.. The Part of the Form Load event that is causing this is as follows:
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Me.Load
Threading.Thread.Sleep(5000)
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I copied a project I wrote on my XP machine to my other computer with Windows 7 64-bit. When I run it through VS2008 it exits immediately. It does not run a single line of code. The exit code is 0. I need to post what else it says. But I did find a posting about this saying the path to the temp files may be wrong for it but he did not know how to change this. If I create a new peoject and put a command button on it, the program runs. So I was wondering if it is something like the temp files or something else. The machine runs a compiled .exe of the program from the XP machone when installed on the Windows 7 machine. So I do not think it is the program not being compatible.
View 5 Replies