controllare i cambiamenti del files system

FileSystemWatcher è un controllo di Visual Basic utile a controllare le modifiche a cartelle o file sotto un percorso definito.

posizionare un ContextMenuStrip in una form

Private Sub Form3_MouseClick(ByVal sender As System.Object, ByVal e As
System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseClick

ContextMenuStrip1.Show(PointToScreen(e.Location))


End Sub

Esempio inserimento dati in MS-Access con parametro

Imports System.Data.OleDb

Dim cn As OleDbConnection
Dim cmd As OleDbCommand



Try
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\programmazione.mdb")
'stringa accesso dati
cn.Open()
cmd = New OleDbCommand("insert into tabella1 (a,b) values('prova',?) ", cn)
cmd.Parameters.Add("@b", OleDbType.Char).Value = TextBox4.Text
cmd.ExecuteNonQuery()


Catch
End Try

cn.Close()

Nota.
Si differenzia rispetto ad SQL (che vuole i nomi @nomi e non il ?)

Esempio inserimento dati in MS-SQL con parametro

Imports System.Data.Sql

Dim cn As SqlClient.SqlConnection
Dim cmd As SqlClient.SqlCommand
Try
cn = New SqlClient.SqlConnection("Data Source=.\SQLEXPRESS;AttachDbFilename= " & Chr(34) & "C:\Program Files\Microsoft SQL Server\MSSQL10.SQLEXPRESS\MSSQL\DATA\vb.mdf" & Chr(34) & ";Integrated Security=True;Connect Timeout=30;User Instance=True")
cn.Open()
cmd = New SqlClient.SqlCommand("insert into table1 (a,b) values('ii',@b) ", cn)
cmd.Parameters.Add("@b", SqlDbType.Char).Value = TextBox3.Text
cmd.ExecuteNonQuery()

Catch
End Try

cn.Close()
Me.Table1TableAdapter.Fill(Me.VbDataSet.Table1)

Note.
Si differenzia rispetto all'insert dei dati in access (che richiede il ?).

Esempio lettura dati da MS-SQL

Imports System.Data.Sql

Dim cn As SqlClient.SqlConnection
Dim cmd As SqlClient.SqlCommand
Dim dr As SqlClient.SqlDataReader
Try
cn = New SqlClient.SqlConnection("Data Source=.\SQLEXPRESS;AttachDbFilename= " & Chr(34) & "C:\Program Files\Microsoft SQL Server\MSSQL10.SQLEXPRESS\MSSQL\DATA\vb.mdf" & Chr(34) & ";Integrated Security=True;Connect Timeout=30;User Instance=True")
cn.Open()
cmd = New SqlClient.SqlCommand("select * from table1 ", cn)
dr = cmd.ExecuteReader()
While dr.Read()
TextBox1.Text = dr(0)
TextBox2.Text = dr(1)
TextBox3.Text = dr(2)
' lettura dati
End While
Catch
End Try

cn.Close()

Esempio inserimento dati in MS-SQL

Imports System.Data.Sql

Dim cn As SqlClient.SqlConnection
Dim cmd As SqlClient.SqlCommand
Try
cn = New SqlClient.SqlConnection("Data Source=.\SQLEXPRESS;AttachDbFilename= " & Chr(34) & "C:\Program Files\Microsoft SQL Server\MSSQL10.SQLEXPRESS\MSSQL\DATA\vb.mdf" & Chr(34) & ";Integrated Security=True;Connect Timeout=30;User Instance=True")
cn.Open()
cmd = New SqlClient.SqlCommand("insert into table1 (a,b) values('RRR','RRR') ", cn)
cmd.ExecuteNonQuery()

Catch
End Try

cn.Close()

Esempio inserimento dati in MS-Access

Imports System.Data.OleDb

Dim cn As OleDbConnection
Dim cmd As OleDbCommand



Try
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\programmazione.mdb")
'stringa accesso dati
cn.Open()
cmd = New OleDbCommand("insert into tabella1 (a,b) values('RRR','RRR') ", cn)
cmd.ExecuteNonQuery()

Catch
End Try

cn.Close()