Loading a Dataset from another form

[johnuk4]

Hi,

I apologise if this is a little basic however my knowledge of programming is fairly none existent. Basically what im doing is selecting some search critera with one form and with a second form i want the results to load in a datagrid when the button is selected on the first form. I have managed to get the data to load on the first form in a datagrid as a test so i know that it all works. The problem i am having is passing the dataset to form 2 to pick up and load in the datagrid. Would anybody know a way of doing this that is fairly simple to implement. I have included to code below to show how i have initiated the data etc.

thanks for any help

johnuk4

               SQLStr = "SELECT Hardware_Problems.Hardware_Problem_Id, Hardware.Hardware_Type, Hardware.Hardware_Make, Hardware.Hardware_Model, Hardware_Problems.Date_Time, Hardware_Problems.Staff_Reported, Hardware_Problems.Problem_Description, Hardware_Problems.Location FROM Hardware INNER JOIN Hardware_Problems ON Hardware.Hardware_Id = Hardware_Problems.Hardware_Id;"

                DatabaseTable = "Hardware_Problems"

            Case Is = "All Other Problems"

            Case Is = "In Location"

                'msgbox for if user hits search without selecting an input
            Case Else
                MsgBox("Please select search criteria", MsgBoxStyle.OKOnly, "Error")
        End Select


        With dbAdaptr
            .TableMappings.Add("Table", DatabaseTable)

            SQLCode = SQLStr
            SQLStr = SQLCode

            cmd = New System.Data.OleDb.OleDbCommand(SQLStr, DBCon)

            cmd.CommandType = CommandType.Text
            .SelectCommand = cmd
            .Fill(DSet)
            .Dispose()

        End With

        DSet.AcceptChanges()

        DSet.Dispose()

        DBCon.Close()

        DataGrid1.SetDataBinding(DSet, DatabaseTable)

        ProgressBar1.Value = 100
    End Sub

[bgard68]

Here is how you pass variables from one form to another:

Form1:
Private dsForm1 as new DataSet

Form2:
Private dsForm2 as new DataSet

Form1:
Dim frm2 as new Form2
dsForm2 = dsForm1
frm2.ShowDialog
'Do some more stuff maybe ?
frm2.close

[johnuk4]

Hi thanks for the reply,

I have tried wot you recommended, however it does not actually pass the variables to form 2. When i call the variable dsForm2 in form 2 it says it has not been declared, obviously as i declared it as a variable in form 1. Do you know if i can pass the value without this problem

thanks again

johnuk4

[bgard68]

After the Windows Generated Code Section,

Do you have Private dsForm2 as new dataset ?


there is another way, but its a little more complex...

1. Create a seperate class file, say clsVars.vb
2. Inside clsVars.Vb: Declare a public property dataset
3. Inside of whatever form: Private clsMyVars as new clsVars after Windows Generated Code
4. clsMyVars.dsMyDataSet = dsForm1
5. Form 2: Private clsVarsForm2 as new clsVars
6. Form 2: you have access to clsVarsForm2

[johnuk4]

yeah, do i have to declare DataSetForm2 on form 1 as well as form 2? sorry i got the above the wrong way round, Its actually on form 1 that it says variable not been declared.

thanks

[bgard68]

Check out this link,

it might clear some things up for you...

http://www.devcity.net/Articles/94/1...#FeedbackPanel

[johnuk4]

Hi,

Thanks for the link it was helpful. Iv tried to set up the class method that u stated but unable to get it to pick up the dataset and another variable i passed in form 2. Could you possibly have a quick look at my code below to see if i have implemented this properly. (Iv Highlighted all of the class areas)

thanks again

Form 1 Code:

Public Class MainScreenForm
    Inherits System.Windows.Forms.Form
    Public frmHardwareProblems As New HardwareType
    Public frmSoftwareProblems As New ReportSoftwareProblem
    Public frmOtherProblems As New ReportOtherProblem
    Public SearchResultsForm As New SearchResults
    Dim tRow As DataRow, tTbl As DataTable
    Dim ConString As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & "Data Source=""ProblemDatabase.mdb"";"
    Dim DBCon As New System.Data.OleDb.OleDbConnection(ConString)

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

     Private clsMyVars As New clsVars

    Private Sub MainScreenForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        With cboSelectOption
            .Items.Add("View All Problems")
            .Items.Add("All Software Problems")
            .Items.Add("All Hardware Problems")
            .Items.Add("All Other Problems")
            .Items.Add("In Location")
            .SelectedIndex = 0 'Set first item as selected item. 
        End With
    End Sub

    Private Sub btnHardwareProb_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnHardwareProb.Click
        Me.Close()
        frmHardwareProblems.ShowDialog()
    End Sub

    Private Sub btnSoftwareProb_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSoftwareProb.Click
        Me.Close()
        frmSoftwareProblems.ShowDialog()
    End Sub

    Private Sub btnOtherProb_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOtherProb.Click
        Me.Close()
        frmOtherProblems.ShowDialog()
    End Sub

    Private Sub MenuItem2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MenuItem2.Click
        Me.Close()
    End Sub


    Private Sub btnSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSearch.Click


        Dim SelectedOption As String
        Dim SQLCode As String

        'variable for selecting what table to be used in the database
        Dim DatabaseTable As String

        ProgressBar1.Value = 0

        DBCon.Open()

        Dim cmd As System.Data.OleDb.OleDbCommand

        Dim dbAdaptr As System.Data.OleDb.OleDbDataAdapter = New System.Data.OleDb.OleDbDataAdapter
        Dim DataSet1 As New DataSet, SQLStr As String

        SelectedOption = cboSelectOption.Text

        'select the correct sql query string depending on what user selects

        Select Case SelectedOption

            Case Is = "View All Problems"


            Case Is = "All Software Problems"

                SQLStr = "SELECT Software_Problems.Software_Problem_Id, Software.Software_Company, Software.Software_Name, Software.Software_Version, Hardware.Hardware_Make, Hardware.Hardware_Model, Software_Problems.Date_Time, Software_Problems.Staff_Reported, Software_Problems.Problem_Description, Software_Problems.Location FROM Hardware INNER JOIN (Software INNER JOIN Software_Problems ON Software.Software_Id = Software_Problems.Software_Id) ON Hardware.Hardware_Id = Software_Problems.Hardware_Id;"

                DatabaseTable = "Software_Problems"

            Case Is = "All Hardware Problems"

                SQLStr = "SELECT Hardware_Problems.Hardware_Problem_Id, Hardware.Hardware_Type, Hardware.Hardware_Make, Hardware.Hardware_Model, Hardware_Problems.Date_Time, Hardware_Problems.Staff_Reported, Hardware_Problems.Problem_Description, Hardware_Problems.Location FROM Hardware INNER JOIN Hardware_Problems ON Hardware.Hardware_Id = Hardware_Problems.Hardware_Id;"

                DatabaseTable = "Hardware_Problems"

            Case Is = "All Other Problems"

            Case Is = "In Location"

                GroupBox3.Visible = True

                'msgbox for if user hits search without selecting an input
            Case Else
                MsgBox("Please select search criteria", MsgBoxStyle.OKOnly, "Error")
        End Select


        With dbAdaptr
            .TableMappings.Add("Table", DatabaseTable)

            SQLCode = SQLStr
            SQLStr = SQLCode

            cmd = New System.Data.OleDb.OleDbCommand(SQLStr, DBCon)

            cmd.CommandType = CommandType.Text
            .SelectCommand = cmd
            .Fill(DataSet1)
            .Dispose()

        End With

        DataSet1.AcceptChanges()

        DataSet1.Dispose()

        DBCon.Close()

        'DataGrid1.SetDataBinding(DataSet1, DatabaseTable)

        ProgressBar1.Value = 100

        'setting dataset to pass variable to results form
        clsMyVars.DatabaseTableSearch = DatabaseTable
        clsMyVars.DataSet1 = DataSet1

        SearchResultsForm.ShowDialog()
    End Sub


End Class

Form 2 code:

Public Class SearchResults
    Inherits System.Windows.Forms.Form


#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

        Private clsVarsForm2 As New clsVars
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Me.Close()
    End Sub


    Private Sub SearchResults_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        DataGrid1.SetDataBinding(clsVarsForm2.DataSet1, clsVarsForm2.DatabaseTableSearch)
    End Sub
End Class

Class File code:

Public Class clsVars
    Public DataSet1 As New DataSet
    Public DatabaseTableSearch As String
End Class

Sorry about all the system code

thanks john

[johnuk4]

Hi, Thanks for all your help, i managed to crack it in the end using the first method you showed me

thanks

johnuk4

[bgard68]

Here is a example...

Make sure you put the database in your c:.