I am re-creating a program that was made in vb6. The vb6 program used winsockets for networking. It could host up to 70 clients and there would be constant communication back and fourth. I have just recently switched to using .NET... (Huge Change) more specifically Visual Studio 2010 express (for now). asically, in effort to re-create this type of data communication I have run into a road block.
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I need to create a function which have either 1 parameter with a string as data type or 2 parameters with double as data type.Something like the substring method.
View 2 RepliesI need to control a device with a GPIB port. I have the commands that I need to use to do this; but I don't know which is the sintaxis in Visual Basic.
For example if I need to send a instruction like "START:0.01" to the external device which are the libraries that I have to include?, how should I write the programming line to do this?
The main tasks that I need to program are sending data, receiving data, and saving data
I am create a mysql table with TIME Data type fields. Like FROMTIME and TOTIME. And some insert data to that table. And that data is view through DataGridView. I can show all data in DATAGRIDVIEW. But, Have a error data, when current row click time ( Error data is : DataGridViewTextCell {ColumnIndex=0,RowIndex=0}.
How to store TIME types to Variables or Control;
For each column in data table i want to add parameter with same data type as column data type. But looks it's not that simple.
Dim cmd As New SqlCommand
Dim dType As New System.Data.SqlDbType
For Each cl As DataColumn In DataTable1.Columns
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How can I do this?
I have a bunch of Excel files full of research data. Everything is strait forward: rows of research categories and columns of research parameters. I want to create a simple search form that allows opening any of the spread sheets that contains the type of data that I specify. For example, I would choose a parameter
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I've been playing around with the TCP client/server sample code I found on [URL] but I can't seem to get it to function correctly. The problem I am having is that if I try to send data from the client a second time I get nothing back, not even an error that it couldn't send data. Every time I run the project it works the first time but that's it. When I was running the code line by line it seems to get to 'networkStream.Read(bytes, 0, CInt(tcpClient.ReceiveBufferSize))' and then it jumps over the rest of the routine.
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I have a problem about button click event and data binding.I have described my problem in the mark as following
Public Class Window1
Private Sub Window_Loaded(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles MyBase.Loaded
Dim list_of_name As New List(Of String)
list_of_name.Add("John")
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I am trying to communicate to a local AS3 Air app on my PC via sockets. The VB.Net app is acting as a server in this case while the Air app is a client. The .Net app sends data every 25ms to the Air app. I have not send any message termination. I just receive the data on Air app and process it.
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I have a gps logger which store the gps data into its internal memory .I have a description file for the data format and how to send commands to the logger to get data . this file is present at the following website L [URL]
I need to make a vb.net application that can download data from the gps logger . and to set its configuration parameters .
I am having some issues with serial port communication. My event handler to poll data is not working. I even tried to retrieve it using a button event, but that also does not work. I know there is data in the buffer.Here's my
Private Sub DataReceived( _
ByVal sender As Object, _
ByVal e As System.IO.Ports.SerialDataReceivedEventArgs)[code]...........
I've been playing around with the TCP client/server sample code I found on [URL] but I can't seem to get it to function correctly. The problem I am having is that if I try to send data from the client a second time I get nothing back, not even an error that it couldn't send data. Every time I run the project it works the first time but that's it. When I was running the code line by line it seems to get to 'networkStream.Read(bytes, 0, CInt(tcpClient.ReceiveBufferSize))' and then it jumps over the rest of the routine.
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I'v designed a ms access database table with one field having Datetime datatype. I can Insert data into it from vb.net front end by trns_dt DateTime.Now.DateBut when I fetch records from the tableand assign the dataset datasource as da, it shows datatype mismatch error.
daleDbDataAdapter("SelectDaily_Transactiondtp_from_dt.value dtp_To.value con)
dsDataSet
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I'm not sure what I have done wrong, I am trying to get my program to send data (UsernamesPasswords) from client to server, then the server says if it's right or wrong.
The error is on this line:
Dim networkStream As NetworkStream = TcpClient.GetStream()
Heres the Client:
Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
If TextBox1.Text = "" Then
MsgBox("You must enter UN/PW!")
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i want to receive data to my pc from external hardware but i don't know how to do it since i am new to vb.net. the code in vb.net to receive data using serial port rs232.
View 1 RepliesI have a program that calculates commission, but if the commission is nothing then I do not want it to show a zero commission. I want a message box to show a message that there is no commission earned.
View 1 RepliesMy colleague gave me a DLL that manage all database business. I wanted to invoke a function that uses Stored Procedure and return the search result. In the function receive a parameter type in ystem.Data.IDataParameter[]. Below is my codes.
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I have a function (on vb.net) to get a data from a XMLWebService:
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I added this lines in the form load of DataGridPrinter by Merrion in the codebank..[code]Unable to cast object of type 'System.Data.DataViewManager' to type 'System.Data.DataTable'.
View 2 Repliesevery time i run this code i get the same error
Unable to cast object of type 'System.Data.DataTable' to type 'System.Data.DataView'.
the code is
Dim plmExcelCon As New System.Data.OleDb.OleDbConnection
Dim cmdLoadExcel As System.Data.OleDb.OleDbDataAdapter
Dim PrmPathExcelFile As String
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[code] "The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value.The statement has been terminated." [code]
View 6 RepliesI have one question. i have seen some codes like:
Req = CType(System.Net.HttpWebRequest.Create("url"), Net.HttpWebRequest)
Is it really necessary to cast the same type, or is there a difference when its not casted.
I have a number of controls (Device1, Device2, etc.) that all inherit from BaseDeviceControl. In the DragEnter event handler I am trying to test for the correct type by using the BaseDevvceControl like this....
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I am pulling data from a local MSSQL database using a stored procedure, then send the data to a web service. Every part of the component works well except for a pesky problem will a DBNull being returned from the DataRow field, when I know that the field is not null and has valid data. The database and associated INSERT statements that add to this field are designed to not allow NULL entries. When I debug break the program on or right before the line that throws the error I see that the field has valid data for the current row.If I add a null check to the code (as below) the operation continues as normal:
Dim dataResultsTable = Me.myViewTableAdapter.GetData(int)
For Each myDataRow In dataResultsTable.Rows
If worker.CancellationPending Then
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Why is the read operation returning DBNull instead of the data in the database?
EDIT: Just to be clear, the operation does return the proper data, but the data is not being saved into the variable.
<ItemsControl DockPanel.Dock="Top" ItemsSource="{Binding Path={x:Static vmc:clsPersonViewModel.ChildrenPath}, Mode=OneWay}">
<ItemsControl.ItemTemplate>
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In the code above, if there are no children (the ChildrenPath property returns NULL), nothing is rendered in the view. In the code below, when ChildrenDataSetPath is NULL the XamDataGrid still gets rendered. How do I achieve the same for a single object (as opposed to a collection) as the datacontext?
<DataTemplate DataType="{x:Type vmb:clsPersonViewModel}">
<igDP:XamDataGrid DataSource="{Binding Path={x:Static vmb:clsPersonViewModel.ChildrenDataSetPath}}">
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If I create a list for a TextBox:
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I am able to only add controls that are of type TextBox. My question to you is, can I create a List to hold more than one control type or do I have to create a list for each control type?
I have an InvalidCastException Error in my program. The program is that i try to insert an employee record into a database table after getting the details from a form. I've used Money data type is SQL Server for salary and SqlTypes.SqlDecimal data type in employee template class. i've used a stored procedure to pass the values and i add the basic value by passing a parameter by the method
Dim prm8 As SqlParameter = com.Parameters.Add("@basic", SqlDbType.Money)
prm8.Direction = ParameterDirection.Input
prm8.Value = emp.Bsc
I've used the money datatype itself even in the stored procedure variable.I get the following error.
failed to convert parameter value from sql decimal to decimal
Even if i use
prm8.Value = Convert.ToDecimal(emp.Bsc)
I get an error Unable to cast object of type 'System.Data.SqlTypes.SqlDecimal' to type 'System.IConvertible'.
I am getting this error when I am tring to load string type to data table)
Using connection As New SqlConnection("connectionstring;")
connection.Open()
Using Command As New SqlCommand("SELECT ClientId,forename,surname from t_clientdetails
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I get the below error Unable to cast object of type 'System.String' to type 'System.Data.DataTable'.This is the code I'm using
Dim str As String = String.Empty
If (Session("Brief") IsNot Nothing) Then
Dim dt As DataTable = Session("Brief")
If (dt.Rows.Count > 0) Then
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error " Unable to cast object of type 'MySql.Data.MySqlClient.MySqlException' to type 'MySql.Data.MySqlClient.MySqlDataReader'. " ?
THIS IS THE CODE Ssql = "SELECT ItemID, Prodname, qty, Desc, Cost * FROM items ORDER BY ItemID ASC"
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