vb.net

vb: add external file for changing connection to database if necessary

F. Zomer — Mon, 01 Mar 2010 10:47:00 GMT

Public Class Form1

Dim connection As SqlConnection = cn()

Public Function cn() As SqlConnection

Dim appPath As String = System.IO.Path.GetDirectoryName(Application.ExecutablePath)

Dim objReader As New System.IO.StreamReader(appPath.ToString() + "\conn.txt")

Dim sLine As String = ""

Dim arrText As New ArrayList()

Dim servernaam As String = ""

Dim datbasenaam As String = ""

Dim connectionString As String = "server=" + servernaam + ";database=" + datbasenaam + ";uid=aplprogs;pwd=321123"

Dim connection As SqlConnection = New SqlConnection(connectionString)

If System.IO.File.Exists(appPath + "\conn.txt") = False Then

'MessageBox.Show("Connectie bestand is niet gevonden!")

Return connection ' empty

End If

'read file

sLine = objReader.ReadLine()

If Not sLine Is Nothing Then

arrText.Add(sLine)

End If

Loop Until sLine Is Nothing

objReader.Close()

'process lines

For Each sLine In arrText

Console.WriteLine(sLine)

' catch variables

If sLine.StartsWith("servernaam") Then servernaam = sLine.Substring((sLine.LastIndexOf(":") + 1), (sLine.Length - (sLine.LastIndexOf(":") + 1))).Trim

If sLine.StartsWith("databasenaam") Then datbasenaam = sLine.Substring((sLine.LastIndexOf(":") + 1), (sLine.Length - (sLine.LastIndexOf(":") + 1))).Trim

connectionString = "server=" + servernaam + ";database=" + datbasenaam + ";uid=aplprogs;pwd=321123"

connection = New SqlConnection(connectionString)

Return connection

End Function

' make a reference
Dim command As New SqlCommand("sp_verSofinrBijBelDienst", connection)

'Connection will be created from upper function + txt file

Maak een bestand aan met als bestandsnaam [conn.txt].

Kies nu in het project [add existing item] en verwijs nu naar het conn.txt bestand.

Bij de properties het volgende wijzgingen:

Build action: Content

Copy to Output Directory: Copy always

deploy project
zoek naar conn.txt.deploy
wijzig evt de connectie info en sla dit op.

Code in C#

public Form1()
{ InitializeComponent(); }

//declare connection
System.Data.SqlClient.SqlConnection connection = getConnection();

//create connection from txt doc
public static System.Data.SqlClient.SqlConnection getConnection()
{
String appPath = System.IO.Path.GetDirectoryName(Application.ExecutablePath);
System.IO.StreamReader objReader = new System.IO.StreamReader(appPath.ToString() + @"\conn.txt");
String sLine = "";
System.Collections.ArrayList arrText = new System.Collections.ArrayList();
String servernaam = "";
String databasenaam = "";
if (System.IO.File.Exists(appPath + @"\conn.txt") == false)
{
return new System.Data.SqlClient.SqlConnection(); //empty
}
while ((sLine = objReader.ReadLine()) != null)
{
arrText.Add(sLine);
}

objReader.Close();
foreach (String Line in arrText)
{
if (Line.StartsWith("servernaam"))
{ servernaam = Line.Substring((Line.LastIndexOf(":") + 1), (Line.Length - (Line.LastIndexOf(":") + 1))).Trim(); }
if (Line.StartsWith("databasenaam"))
{ databasenaam = Line.Substring((Line.LastIndexOf(":") + 1), (Line.Length - (Line.LastIndexOf(":") + 1))).Trim(); }
}
String connectionstring = "server=" + servernaam + ";database=" + databasenaam + ";uid=aplprogs;pwd=321123";
System.Data.SqlClient.SqlConnection connection = new System.Data.SqlClient.SqlConnection(connectionstring);

return connection;
}

//using the connection to connect to a sql server/table and present some data in a multiline textbox
private void button1_Click(object sender, EventArgs e)
{
txtUzovi.Text = "";
System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand();
System.Data.SqlClient.SqlDataReader reader;
cmd.CommandText = "select columnname from tablename";
cmd.CommandType = CommandType.Text;
cmd.Connection = connection;
connection.Open();
reader = cmd.ExecuteReader();

if (reader.HasRows)
{
while (reader.Read())
{ //fill the textbox
txtBox1.AppendText(reader.GetString(0) + "\r\n");
}
}
else
{//Console.WriteLine("No rows found.");
}

reader.Close();
}

VB: write text to file

F. Zomer — Tue, 03 Feb 2009 17:00:00 GMT

Dim objWriter As New System.IO.StreamWriter("c:\test2.txt", True)
objWriter.WriteLine("text text")

objWriter.Flush()
objWriter.Close()
objWriter.Dispose()

VB: How to write data to sql table

F. Zomer — Tue, 27 Jan 2009 11:18:00 GMT

Speciaal op verzoek van 'Duppie': Hoe schrijf ik data naar een SQL tabel in Dot Net?
(And specially for 'Duppie': How to write data to a SQL table in Dot Net?)

Place one button on a form and paste the code under the click event form the button

Imports System.Data.SqlClient

Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim cn As New SqlConnection("server=XXX;database=XXX;uid=XXX;pwd=XXX")
Dim regel As String = "blabla"
Dim SQLstring As String = "insert into dbo.Tabel (tekst) values ('" & regel & "')"
Dim Appcmd As New SqlCommand(SQLstring, cn)

Try

cn.Open()
Appcmd.ExecuteNonQuery()

Catch ex As Exception

MsgBox(ex.Message)

Finally

cn.Close()

End Try

regel = ""
SQLstring = ""

End Sub

End Class

VB: teken voor teken uitlezen van een bestand

F. Zomer — Thu, 20 Nov 2008 15:13:00 GMT

Try

Dim path As String = filelocation

Dim sr As System.IO.StreamReader = New System.IO.StreamReader(path)

Do While sr.Peek() >= 0

Console.Write(Convert.ToChar(sr.Read()))

Loop

sr.Close()

Catch e As Exception

Console.WriteLine("The process failed: {0}", e.ToString())

End Try

How to open an explorer in visual basic dot net

F. Zomer — Wed, 18 Jun 2008 15:06:00 GMT

Er zijn 2 mogelijkheden:

System.Diagnostics.Process.Start("explorer.exe", "D:\")

Microsoft.VisualBasic.Shell("c:\windows\explorer.exe", AppWinStyle.NormalFocus)

getting the return value of a stored proc in visual basic

F. Zomer — Mon, 16 Jun 2008 22:12:00 GMT

n eerst de stored procedure aanmaken

CREATE PROCEDURE updateCurrentStatus

@berichtnummer bigint

update workflowstreamingobject

…..etc etc

RETURN @@ROWCOUNT

n rechten op de stored procedure goedzetten

n dot net code

Dim theCommand As New SqlClient.SqlCommand()

theCommand.CommandType = CommandType.StoredProcedure

theCommand.Connection = cn

theCommand.CommandText = "updateCurrentStatus"

theCommand.Parameters.AddWithValue("@berichtnummer", berichtnummer)

theCommand.Parameters.Add("@returnvalue", SqlDbType.Int, 10).Direction = ParameterDirection.ReturnValue

Try

cn.Open()

theCommand.ExecuteNonQuery()

Catch ex As Exception

MsgBox(ex.Message)

Finally

cn.Close()

End Try

Dim rowCount As Int32 = CInt(theCommand.Parameters("@returnvalue").Value)

MsgBox(rowCount)

How to send a NET SEND in visual basic

F. Zomer — Wed, 09 Apr 2008 13:20:00 GMT

System.Diagnostics.Process.Start("NET", "send pcname text.")

How to clear a datagridview

F. Zomer — Thu, 03 Apr 2008 16:41:00 GMT

' clear datagrid (where b is the tablename in the dataset)
If ds.Tables.Contains("b") = True Then
ds.Tables("b").Clear()
End If

' after this you can fill the datagrid again beginning with no records from the previous selection.

how to change the value of a existing hashtable key + presting the hashtable in a datagrid.

F. Zomer — Tue, 01 Apr 2008 16:16:00 GMT

I want to change the value of a existing row in a hashtable by iterating through a sql datatable and finally present the result of the hashtable in a datagrid.

Dim sl As New Hashtable

For Each f In My.Computer.FileSystem.GetFiles(Me.Label26.Text)

' bepaal type (by iterating through the sql table)
' ...
Dim Type As String = modAlg.QresultsScalar("select best_eistandaard_identificatie from VerwerkDeclaratie where vd_id = '" & IO.Path.GetFileNameWithoutExtension(f) & "'", cn)
' ...you have solve this on your own

' maak een nieuwe record aan in Hashtable of hoog de value met 1 op als het record al bestaat
If sl.ContainsKey(Type) Then
For Each de As DictionaryEntry In sl
If de.Key = Type Then
' grote truuk: wijzig de [value] van de hashtable met de nieuwe waarde!!!!!!!!!!!!!!!!!!!!!!!!!!!
sl(Type) = de.Value + 1
Exit For
End If
Next

Else

' add new record
sl.Add(Type, 0)
End If
Next

' create table
Dim dt As New DataTable
dt.Columns.Add("type")
dt.Columns.Add("aantal")

'fill the table with values from the hash table
For Each de As DictionaryEntry In sl
dt.Rows.Add(de.Key, de.Value)
Next

' bind the table to the datagrid
Me.DataGridView1.Rows.Clear()
Me.DataGridView1.DataSource = dt

'let's assume that the user was looking for a certain key
Dim selType As String = inputvalue
If Not sl.ContainsKey(selType.ToUpper) Then
MsgBox("non existing")
Exit Sub
Else
MsgBox("there are " & sl.Item(selType.ToUpper).ToString & " item(s).")
End If

search in the value side of a hashtable to get the key of that record

F. Zomer — Thu, 27 Mar 2008 10:50:00 GMT

Tsja, normaal zoek je een key waarde op een wil je de value hebben. Dit keer il ik het precies andersom hebben!
Waarom? Omdat ik de hashtable laat vullen met een bestandsnaam + locatie. Ik weet dat de bestandsnamen meerdere keren kunnen voorrkomen, maar
een bestandslocatie is altijd uniek. Ik gebruik deze bestandslocatie dan ook als key.

1. fill hashtable

Dim ht As New Hashtable
Dim pad As String = "c:\temp"

For Each M As String In My.Computer.FileSystem.GetDirectories(pad, FileIO.SearchOption.SearchAllSubDirectories)

    ' bestanden doorlopen
    For Each b As String In My.Computer.FileSystem.GetFiles(M)
    ht.Add(b, getFileName(b))
    Next

Console.WriteLine(ht.Count)
Next

2. get location (via sql doorloop ik nu een tabel met VALUE waarden om zo de locatie te kunnen bijwerken)

{....
Dim SelectCommand As New SqlCommand("SELECT " & idveld & " FROM " & tabelnaam, cn0)
cn0.Open()
...}

Dim DbReader As SqlDataReader = SelectCommand.ExecuteReader(CommandBehavior.CloseConnection)
While DbReader.Read

' doorloop de hashtable om de matchende value op te zoeken, is er een hit dan wordt de key (de.value) genomen
For Each de As DictionaryEntry In ht
If de.Value = DbReader(idveld) Then
{...QueryUitvoer("update " & tabelnaam & " set path = '" & de.Key & "' WHERE " & idveld & "='" & de.Value & "'")...}
End If
Next

End While

DbReader.Close()
cn.Close()