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David L. Hansen
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How can I implement autocompletion in a combobox that has a generic list as its datasource?

I've created a generic list (a collection) and made it the dataSource for my combobox.  
Now I need to use autocompletion for when the user begins to type in the combobox while searching for something in the list.  There seems to be a good amount of help on the web for autocompletion where the combobox has a different kind of datasource (ie. datatable) but I'm still scratching my head trying to get this to work with a generic list.  

.NET ProgrammingC#Visual Basic.NETWeb Languages and StandardsProgramming

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David L. Hansen

8/22/2022 - Mon

A generic list of what? Strings? Custom objects?
David L. Hansen

Custom objects.  Each item (object) has several properties and methods.  The collection object which holds these items uses the System.ComponentModel.BindingList(Of T) where T is my custom object.
David L. Hansen

The collection object is the combobox's datasource.
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David L. Hansen

Ahh Monday, back to work.  BTW, thanks for your help on this.

So, when I use:
this.comboBox1.AutoCompleteSource = AutoCompleteSource.ListItems;

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I get the following error - "Value of type 'System.Windows.Forms.AutoCompleteSource' cannot be converted to 'System.Windows.Forms.AutoCompleteStringCollection'.

Can you post your implementation? The code I posted was a working sample.
David L. Hansen

Sure, here it is:
Private Sub frmOfficiant_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Officiants = New Officiants
        Dim blankOfficiant As New Officiant 'this is provided for the user to add a new officiant if need be
        Officiants.Insert(0, blankofficiant)

        With Me.cboOfficiantLastName
            .DataSource = Officiants
            .DisplayMember = "LastName"
            .AutoCompleteMode = AutoCompleteMode.SuggestAppend
            .AutoCompleteCustomSource = AutoCompleteSource.ListItems
        End With

End Sub


Public Class Officiants
    Inherits System.ComponentModel.BindingList(Of Officiant)

    'the following three subs allow this class to know when a 
    'new item is inserted, added, or the list is changed. 
    Protected Overrides Sub InsertItem(ByVal index As Integer, ByVal item As Officiant)
        MyBase.InsertItem(index, item)
    End Sub

    Protected Overrides Sub OnAddingNew(ByVal e As System.ComponentModel.AddingNewEventArgs)
    End Sub

    Protected Overrides Sub OnListChanged(ByVal e As System.ComponentModel.ListChangedEventArgs)
    End Sub

    Public Sub RefreshFromDatabase()

        Dim strsql As String = _
            "SELECT officiant_id, title, first_name, " & _
            " last_name, address1, address2, " & _
            " city, state, zip, " & _
            " phone " & _
            "FROM Officiant " & _
            "--where --ADD WHERE STATEMENT HERE "

        Dim drItems As SqlClient.SqlDataReader
        drItems = DataSrc.GetDataReader(strsql)

        'clear current list 

        'cycle through all items and add to list 
        While drItems.Read
            Dim x As New Officiant
            x.OfficiantId = CInt(NullToZero(drItems("officiant_id")))
            x.Title = CStr(NullToBlank(drItems("title")))
            x.FirstName = CStr(NullToBlank(drItems("first_name")))
            x.LastName = CStr(NullToBlank(drItems("last_name")))
            x.Address1 = CStr(NullToBlank(drItems("address1")))
            x.Address2 = CStr(NullToBlank(drItems("address2")))
            x.City = CStr(NullToBlank(drItems("city")))
            x.State = CStr(NullToBlank(drItems("state")))
            x.Zip = CStr(NullToBlank(drItems("zip")))
            x.Phone = CStr(NullToBlank(drItems("phone")))
        End While

        'close the datareader 

    End Sub


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David L. Hansen

Was that helpful?
David L. Hansen

Any ideas?
David L. Hansen

Finally found the issue!  I had:
 .AutoCompleteCustomSource = AutoCompleteSource.ListItems

instead of:
.AutoCompleteSource = AutoCompleteSource.ListItems

I just couldn't see the difference even though it was right there in front of me.
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