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Yes thanks my problem is solved
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That's a very interesting article - thanks . A point though, the last paragraph of that article reads
Of course, dynamically generating, compiling, and running code in this way is not a good solution when you need maximum performance. But you will agree with me that the flexibility of this approach could be decisive in a lot of situations.
Considering that Richard's app is getting data through RS232 feeds, he's probably incurring some performance loss already and will most likely want to keep the rest of his app's performance as high as possible. Apart from that, it's really only a simple calculation that needs doing and my personal opinion is that implementing dynamically created and compiled code is going a bit overkill (still is a great article though).
Just an opinion.
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This gives me an error and I've tried changing the values and formats within the brackets.
Dim strconn As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\VilliageDatabase\Ainslie.mdb"<br />
Dim Sql As String = "Insert into tblTransaction values(#12/05/06#,1,1,100,'this is it')"<br />
Dim Sql2 As String = "Insert into tblTransaction values()"<br />
Dim conn As New OleDbConnection(strconn)<br />
Dim cmd As New OleDbCommand(Sql, conn)<br />
conn.Open()<br />
cmd.ExecuteNonQuery()
Is this pretty far off how you do an insert statement ?
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have you tried inserting the fields?
"Insert into tblTransaction values(#12/05/06#,1,1,100,'this is it')7"
"Insert into tblTransaction (field1,field2 ....) values(#12/05/06#,1,1,100,'this is it')7"
GUERVEN
Truth or Consequence
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Also the newrow statement falls over with "null reference" when I code the dataadapter but not when
I add in a dataadapter from the wizard. So what should the sql be here ? or the command so that I can creat a new row ?
Dim strConn As String = " Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\VilliageDatabase\Ainslie.mdb"<br />
Dim conn As New OleDbConnection(strConn)<br />
Dim Sql As String = "select * from tblTransaction"<br />
Dim adapter As OleDbDataAdapter<br />
adapter = New OleDbDataAdapter(Sql, conn)<br />
Dim ds As New DataSet<br />
Dim intc As Integer<br />
Dim str As String<br />
intc = adapter.Fill(ds)<br />
' str = ds.Tables(0).Rows(0).Item(4)<br />
Me.Text = str<br />
<br />
<br />
Dim newrow As DataRow = ds.Tables("tblTransaction").NewRow
Please if you can help ?
ml
-- modified at 5:24 Thursday 27th July, 2006
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You didn't tell the DataSet what the name of the tables are. Try: ds.Tables(0).NewRow
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HI.
from the flow of the code I assume you want to fill a datatable and then create a new row from it.
you can directly fill a datatable without using a dataset. Here I replaced some of the code.
With this method, you have a direct access to the dattable.
Dim strConn As String = " Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\VilliageDatabase\Ainslie.mdb"<br />
Dim conn As New OleDbConnection(strConn)<br />
Dim Sql As String = "select * from tblTransaction"<br />
<br />
<big>Dim TblTrans as new datatable</big><br />
<br />
Dim adapter As OleDbDataAdapter<br />
adapter = New OleDbDataAdapter(Sql, conn)<br />
<br />
conn.open()<br />
<br />
intc = adapter.Fill(<big>TBLtrans</big>)<br />
<br />
Dim newrow As DataRow = <big>TBLtrans.NewRow</big>
furthermore, you can filter the datatable using its defaultview without using an extra dataview.
TblTrans.DefaultView.RowStateFilter=DataViewRowState.Added <br />
Datagrid1.datasource = TBLtrans.defaultview
GUERVEN
Truth or Consequence
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Hi guys,
i'm going to implement one windows project in VB.net,
actually i'm new to vb.net, i decided to use advance controls in vb.net which should more user friendly
could any one tell me about the advanced controls in vb.net 2003
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I have a unbounded grid and 1 of the column...columns style is combobox binded to a table.
I want to handle the selectedvalue change event of the combobox.
How it can be done easily
Please help as i am relatively new to .Net
Thanx
Riyaz Zujer Patanwala
I.T.Programmer
Al Jaber Energy Services
P.O.Box 47467
Abu Dhabi
U.A.E.
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I am looking quite a while to find the source code for copying an entire folder + contents to a target folder.
Can anyone help me?
Because if i dont have that code, the program im working on can't be finished.
Thanks, Zaegra
--Zaegra--
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From MSDN (http://msdn.microsoft.com)
The following example determines whether a specified directory exists, deletes it if it does, and creates it if it does not. This example then moves the directory, creates a file in the directory, and counts the files in the directory.
[Visual Basic]
Imports System
Imports System.IO
Public Class Test
Public Shared Sub Main()
'Specify the directories you want to manipulate.
Dim path As String = "c:\MyDir"
Dim target As String = "c:\TestDir"
Try
' Determine whethers the directory exists.
If Directory.Exists(path) = False Then
' Create the directory.
Directory.CreateDirectory(path)
End If
If Directory.Exists(target) Then
' Delete the target to ensure it is not there.
Directory.Delete(target, True)
End If
' Move the directory.
Directory.Move(path, target)
'Create a file in the directory.
File.CreateText(target + "\myfile.txt")
'Count the files in the target.
Console.WriteLine("The number of files in {0} is {1}", _
target, Directory.GetFiles(target).Length)
Catch e As Exception
Console.WriteLine("The process failed: {0}", e.ToString())
End Try
End Sub
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Im reading data from a PIC Micro-controller that is sent to the PC via RS232. I read a voltage with the micro, that is returned as a two byte value. The bytes are sent to the PC LSb first, so I need to 'flip' the byte around. Eg: 1011000 I needs to be converted to 0001101. I need to then concatenate the two bytes after they have been reversed, and use this value in a calculation.
At the moment, I receive the data as two bytes, convert them to binary strings (Convert.tostring(byte, 2)), use a for loop to reverse the order of each string byte, concatenate them, and then convert that back to a double to do my calculation
Is there an easier way of doing this?
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Yep - string reverse function.
Assuming you have the string in a label...
'reverse the string in Label1
Label2.Text = StrReverse(Label1.Text)
Simple as. Nifty eh?
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Hey,
Using message boxes in my vb.net application...
But when I test it, some of those MsgBoxs won't appear on top...
They will just appear on taskbar and application keeps focus...
Does anyone know a way to make sure the MsgBox appears on top,
and blocks application until a button is clicked?
Thanks in advance...
NNM
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Has the form that calls the message box been instantiated with ShowDialog?
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No...
One simple example of how I use it:
(sub)
(...)
If password1.Text <> password2.Text Then 'alert and stop operation:
MsgBox("The passwords in the two password fields do not match", 0, "Error")
(...)
(exit sub)
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i'm using VB6, i wonder how to link my DBF file in my system. I want to edit and add some information by using VB6.
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of course. but no solution.
Pls post here if u found one.
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campbells wrote: of course. but no solution.
I've never worked with DBF but connectionstrings.com[^] has stuff for connecting to .dbf. Not sure if it's what you're looking for.
That's no moon, it's a space station. - Obi-wan Kenobi
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what exactly is this DBF file.
is this the one that comes with a shape file? or a foxpro db?
GUERVEN
Truth or Consequence
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