Combobox control

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.

in form load event u can clear the items in combobox

Code:

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ComboBox1.Items.Clear

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if u want the comboBox selectIndex reset

Code:

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ComboBox1.SelectedIndex = -1

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This will just clear the box

Code:

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Combo1.Text = ""

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

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

Code:

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

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Insert the instruction immediately after this, so you get -

Code:

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

---

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

The only 2 properties I touched in the ComboBox were -

DataSource eg, MyDatabase.mdb - MyTable
DisplayMember - MyFieldName

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
-----------------------------------------------------------------------------------------------

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

Just leave this as an active event

Code:

---

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

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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.

Try shifting the instructions to the

Form1_Activated event

Code:

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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)

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

Use selected index property as combobox style is dropdownlist.

Code:

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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

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No luck!!

Why do you need ?

Code:

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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

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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

Did you ever figure out how to do this? I want to do the same thing. I have several combo boxes on a form for the user to filter out what they want on a report. They are not usually going to put a filter on every combox box (probably just one) so I want the first item to be blank in each combobox and I want that blank item to show when the form first loads. Or is there a way to put a blank in the fill?