How to add an item to the top of a combobox? Thanks.

Hello,

I have a combobox which is populated using datatable:

Code:

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                Dim dt As New DataTable
                dt = GetPatientList()

                cbEPCDPatient.DataSource = dt
                cbEPCDPatient.DisplayMember = "Patient"
                cbEPCDPatient.ValueMember = "ID"

---

I want to add a new item manually as the first item in the combobox, here is what I added right after the above code:

Code:

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                cbEPCDPatient.Items.Add(New DictionaryEntry("Select Patient", 0))

---

It seems this item is NOT added to the combobox.

What is the right way to make this?

Thank you very much.

You would use the Insert method rather than the Add method:

Code:

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MyComboBox.Items.Insert(0, "First Item")

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Edit - I just realized that your ComboBox is bound to a DataTable. If this is the case, then you would need to insert a row to your DataTable:

Code:

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Dim r As DataRow = dt.NewRow()
r(0) = "Hello World!"

dt.Rows.InsertAt(r, 0)

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Thank you for your quick reply:

Code:

---

                Dim dt As New DataTable
                dt = GetPatientList()

                cbEPCDPatient.DataSource = dt
                cbEPCDPatient.DisplayMember = "Patient"
                cbEPCDPatient.ValueMember = "ID"

                'Dim r As DataRow = dt.NewRow()
                'r(0) = "Select Patient"

                'dt.Rows.InsertAt(r, 0)

                cbEPCDPatient.Items.Add(New DictionaryEntry("Select Patient", 0))

---

After added the code, the combobox shows no item at all, how do I fix it?

After debugging, I believe the issue rests here:
r(0) = "Select Patient"

You've got it in the wrong order, do this instead;

Code:

---

Dim dt As New DataTable
dt = GetPatientList()

Dim r As DataRow = dt.NewRow()
r(0) = "Select Patient"
dt.Rows.InsertAt(r, 0)

cbEPCDPatient.DataSource = dt
cbEPCDPatient.DisplayMember = "Patient"
cbEPCDPatient.ValueMember = "ID"

---

Fixed. Thank you.

Code:

---


                Dim dt As New DataTable
                dt = GetPatientList()

                Dim r As DataRow = dt.NewRow()
                Try
                    r("ID") = 0
                    r("Patient") = "Select Patient"
                Catch ex As Exception
                    Throw ex
                End Try


                dt.Rows.InsertAt(r, 0)

                cbEPCDPatient.DataSource = dt
                cbEPCDPatient.DisplayMember = "Patient"
                cbEPCDPatient.ValueMember = "ID"

---