Combobox control

[laxatcg1]

I use a combobox wherein the user may type his value or select from the dropdownlist. In this schenario, everytime when the user opens the form, I want the combobox control to reset/refresh (I mean no value should be displayed). Now I have my first value selected always. Please help me out. Thnx.

[aniskhan]

in form load event u can clear the items in combobox

ComboBox1.Items.Clear

if u want the comboBox selectIndex reset

 ComboBox1.SelectedIndex = -1

[George1111]

This will just clear the box

Combo1.Text = ""

[laxatcg1]

It's a Databound control. Then how do I go about?

[George1111]

The the Form_Load event you will have something like the following code -

        Me.MyTableTableAdapter.Fill(Me.MyDatabaseDataSet.MyTable)

Insert the instruction immediately after this, so you get -

        Me.MyTableTableAdapter.Fill(Me.MyDatabaseDataSet.MyTable)
         ComboBox1.Text = ""

[laxatcg1]

Am still not getting it. Am I doing anything wrong with the control's property?

[George1111]

The only 2 properties I touched in the ComboBox were -

DataSource eg, MyDatabase.mdb - MyTable
DisplayMember - MyFieldName

[laxatcg1]

Am posting my sample code below. Please check that out.

-----------------------------------------------------------------------------------------------
Public Class Form2

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Me.Close()
End Sub

Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.MyTableTableAdapter.Fill(Me.MyDatabaseDataSet.MyTable)
ComboBox.Text = ""
End Sub

Private Sub ComboBox_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox.SelectedIndexChanged
'am doing some actions here.....

End Sub

End Class
-----------------------------------------------------------------------------------------------

[George1111]

I would comment out everything except the Form Load event and see how that effects the result

Just leave this as an active event

Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.MyTableTableAdapter.Fill(Me.MyDatabaseDataSet.MyTable)
ComboBox.Text = ""
End Sub

[laxatcg1]

It works fine. But after I type some value close the form and then reopen the form then the first value from the dropdownlist is getting displayed. Actually I want this control to be blank whenever I close and open the form. Hope am clear.

[George1111]

Try shifting the instructions to the

Form1_Activated event

Private Sub Form2_Activated (ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.MyTableTableAdapter.Fill(Me.MyDatabaseDataSet.MyTable)
ComboBox.Text = ""
End Sub

By doing this it should load and clear the combobox each time the form is activated (rather than just once - only when it is loaded the first time)

[laxatcg1]

No luck! It still displays the first value from the dropdownlist. Is it because of the actions that am doing inside the 'ComboBox_SelectedIndexChanged'. I have given below the complete and final code. I kindly request you to check out. Thank you.

************************************************************
Public Class Form2

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
'This is Cancel button
Me.Close()
End Sub


Private Sub Form2_Activated(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.MyTableTableAdapter.Fill(Me.MyDatabaseDataSet.MyTable)
ComboBox.Text = ""
End Sub


Private Sub ComboBox_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox.SelectedIndexChanged
If (ComboBox.Text = "xxxx xxxx xxxx xxxx xxxx") Then
' .... am doing some actions here.....
End If

End Sub

End Class

[aniskhan]

Use selected index property as combobox style is dropdownlist.

Public Class Form1

    Dim conn As New OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\attendence.mdb;Persist Security Info=False")
    Dim dt As New DataTable

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Dim adapter As New OleDb.OleDbDataAdapter("SELECT * FROM student", conn)

        conn.Open()
        adapter.Fill(dt)
        dt.TableName = "Student"
        conn.Close()

        ComboBox1.DataSource = dt
        ComboBox1.DisplayMember = "rno"

        ComboBox1.SelectedIndex = -1

    End Sub

End Class

[laxatcg1]

No luck!!

[George1111]

Why do you need ?

Private Sub ComboBox_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox.SelectedIndexChanged
If (ComboBox.Text = "xxxx xxxx xxxx xxxx xxxx") Then
' .... am doing some actions here.....
End If

You tell me that if this event is not in the code then everything is fine -
So .... why do you need THIS event - I'm sure there are other ways to do what you are doing in THIS event


Also, you may like to explain what you are trying to achieve overall - there may be a better way to deal with your problem.

The fact you are having big problems with a rather basic control (ComboBox) indicates that you just may be trying to do something it was not designed to do