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Thread: save control

  1. #1

    Thread Starter
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    Jul 2001
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    283

    save control

    i want to save a treeview object when the user clicks a button in the application, so that the user can load again anytime, even if the application is closed and reopened. any ideas how to do this?

  2. #2
    Hyperactive Member
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    post some more details as from what you describe most of usewould populate the treeview from a dataset, containing the last saved information

  3. #3

    Thread Starter
    Registered User
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    Jul 2001
    Posts
    283

    datasets

    you're right. a dataset is probably a more elegant way of doing this. do you have a link where i can find a tutorial on working with datasets?
    thanks...

  4. #4
    Hyperactive Member
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    better strill here is some working code!, now remember I have left out the dim statementz and it maybe a little dificult to follow, so if you have a follow up request feel free to ask:

    But the basic logic is there:

    Dim OledbStr As String = "Select * from Localities "
    Dim Cmd1 As OleDbCommand = New OleDbCommand(OledbStr, Cn1)
    Cn1.Open()
    Cn2.Open()
    Cn3.Open()
    Dim dr1 As OleDbDataReader = Cmd1.ExecuteReader()
    TreeView1.BeginUpdate()
    TreeView1.Nodes.Clear()
    Dim AllNode As New ViewNode("All locations", 0, 0)
    TreeView1.Nodes.Add(AllNode)

    Dim TreePos As Integer = 1
    While dr1.Read
    Dim LocNode As New ViewNode(dr1("Locality"), 0, 0)
    AllNode.Nodes.Add(LocNode)

    OledbStr = "Select * from PropAvail where Locality = '" & Trim(dr1("Locality")) & "'"
    Dim Cmd2 As OleDbCommand = New OleDbCommand(OledbStr, Cn2)
    Dim dr2 As OleDbDataReader = Cmd2.ExecuteReader()

    While dr2.Read
    Dim PropNode As New ViewNode((Trim(dr2("Adr1")) & "," & Trim(dr2("Adr2"))), dr2("Proprty"), 0)
    LocNode.Nodes.Add(PropNode)

    OledbStr = "Select * from PropUnitAvailable where Proprty = " & CStr(dr2("Proprty"))
    Dim Cmd3 As OleDbCommand = New OleDbCommand(OledbStr, Cn3)
    Dim dr3 As OleDbDataReader = Cmd3.ExecuteReader()
    Dim Headline As String
    While dr3.Read
    If IsDBNull(dr3("Headline")) Then
    Headline = "No Headline"
    Else
    Headline = dr3("Headline")
    End If

    Dim UnitNode As New ViewNode((Trim(dr3("PropertyAdr")) & "," & Trim(Headline)), dr3("Proprty"), dr3("Unit"))
    PropNode.Nodes.Add(UnitNode)
    End While
    dr3.Close()
    Cmd3 = Nothing
    End While
    dr2.Close()
    Cmd2 = Nothing

    End While
    TreeView1.EndUpdate()


    Iterms such as ViewNode are classes which inherit the treenode and add adddtional properties
    here is the class which defines viewnode:

    Public Class ViewNode
    Inherits TreeNode

    Public Name As String
    Public Proprty As Integer
    Public Unit As Integer


    Sub New(ByVal Title As String, ByVal Proprty1 As Integer, ByVal Unit1 As Integer)
    MyBase.New()
    Name = Title
    Proprty = Proprty1
    Unit = Unit1
    Me.Text = Name
    End Sub
    End Class

    Not your complete answer just some sample code to point you in the right direction

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