Drag and Drop on a Web Form

Imports System.Data.OleDb
Imports System.Data

Partial Class DragAndDrop
    Inherits System.Web.UI.Page

    Shared myCount As Integer = 0

    Dim FilePath As String = Server.MapPath("Database\Database.mdb")
    Dim conString As String = "Provider=microsoft.jet.OLEDB.4.0;" & _
                   "Data Source =" & FilePath
    'Setter opp connection og leseren
    Dim conn As New OleDbConnection(conString)

    Dim selectString As String
    Dim cmd As OleDbCommand
    Dim reader As OleDbDataReader

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not IsPostBack Then
            AddName.Visible = False
        End If

    End Sub


    Protected Sub Page_LoadComplete(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.LoadComplete
        conn.Open()
        selectString = "SELECT * FROM tblxy"
        cmd = New OleDbCommand(selectString, conn)
        reader = cmd.ExecuteReader()

        While reader.Read()
            Dim textBox As TextBox = New TextBox()
            textBox.ID = reader.Item("Id")
            textBox.Text = reader.Item("Name").ToString
            textBox.Style.Value = "left: " & reader.Item("xpos") & "px; position: absolute; top: " & reader.Item("ypos") & "px"
            textBox.CssClass = "drag"
            textBox.Attributes.Add("onmousedown", "whichElement(event)")
            textBox.Attributes.Add("onmouseup", "mymouseup(event)")
            myPlaceHolder.Controls.Add(textBox)
        End While
        reader.Close()
        conn.Close()

    End Sub


    Private Sub Add()

        xpos.Text = ""
        ypos.Text = ""
        id.Text = ""

        myCount += 1

        If myCount = 1 Then
            selectString = "Insert into tblxy (xpos, ypos) Values (" & _
                                                 "'" & 25 & "'," & _
                                                  "'" & 75 & "')"


            If conn.State = ConnectionState.Closed Then conn.Open()

            cmd = New OleDbCommand(selectString, conn)
            cmd.ExecuteNonQuery()
            If conn.State = ConnectionState.Open Then conn.Close()


            xpos.Text = "25"
            ypos.Text = "75"
            id.Text = FindLastId()

        Else
            myCount = 0
        End If

    End Sub

    Private Function FindLastId() As String

        selectString = "Select max(id) FROM tblxy"
        If conn.State = ConnectionState.Closed Then conn.Open()

        Dim cmd = New OleDbCommand(selectString, conn)

        Dim Id As String
        Id = cmd.ExecuteScalar()

        If conn.State = ConnectionState.Open Then conn.Close()

        Return Id
    End Function


    Private Sub Delete()
        If id.Text.Length > 0 Then

            Dim MYid() As String = Split(id.Text)

            For i As Integer = 0 To MYid.Length - 1
                If MYid(i) <> "" Then

                    If conn.State = ConnectionState.Closed Then conn.Open()
                    selectString = "DELETE FROM tblxy WHERE(Id =" & MYid(i) & ")"
                    cmd = New OleDbCommand(selectString, conn)
                    reader = cmd.ExecuteReader()
                    reader.Close()
                    If conn.State = ConnectionState.Open Then conn.Close()

                    xpos.Text = ""
                    ypos.Text = ""
                    id.Text = ""

                End If
            Next
        End If

    End Sub

    Private Sub Update()

        If xpos.Text.Length > 0 And ypos.Text.Length > 0 And id.Text.Length > 0 Then
            If AddName.Text.Length > 0 Then

                selectString = "Update (tblxy) Set " & _
                                          "xpos=" & "'" & xpos.Text & "'," & _
                                          "ypos=" & "'" & ypos.Text & "'," & _
                                           "Name=" & "'" & AddName.Text & "'" & _
                                          " WHERE Id=" & id.Text & ""

                If conn.State = ConnectionState.Closed Then conn.Open()

                cmd = New OleDbCommand(selectString, conn)
                cmd.ExecuteNonQuery()
                If conn.State = ConnectionState.Open Then conn.Close()

                xpos.Text = ""
                ypos.Text = ""
                id.Text = ""
                AddName.Text = ""
                AddName.Visible = False

            Else

                Dim MYxpos() As String = Split(xpos.Text)
                Dim MYypos() As String = Split(ypos.Text)
                Dim MYid() As String = Split(id.Text)


                For i As Integer = 0 To MYid.Length - 1
                    If MYid(i) <> "" Then


                        selectString = "Update (tblxy) Set " & _
                                                                  "xpos=" & "'" & MYxpos(i) & "'," & _
                                                                  "ypos=" & "'" & MYypos(i) & "'" & _
                                                                  " WHERE Id=" & MYid(i) & ""

                        If conn.State = ConnectionState.Closed Then conn.Open()

                        cmd = New OleDbCommand(selectString, conn)
                        cmd.ExecuteNonQuery()
                        If conn.State = ConnectionState.Open Then conn.Close()
                    End If
                Next

                xpos.Text = ""
                ypos.Text = ""
                id.Text = ""
            End If


        End If

    End Sub

    Protected Sub RadioButtonList1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles RadioButtonList1.SelectedIndexChanged
        If RadioButtonList1.SelectedIndex = 0 Then 'Normal


        ElseIf RadioButtonList1.SelectedIndex = 1 Then 'Update

            Update()
            RadioButtonList1.SelectedIndex = 0
            AddName.Visible = False
            AddName.Text = ""

        ElseIf RadioButtonList1.SelectedIndex = 2 Then 'Add
            Add()
            AddName.Visible = True
            RadioButtonList1.SelectedIndex = 0

        ElseIf RadioButtonList1.SelectedIndex = 3 Then 'Delete
            Delete()
            RadioButtonList1.SelectedIndex = 0

        End If

    End Sub


End Class