VB.NET – .NET automatically completes text box, support separator

Private Sub txtToEmail_EditValueChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtToEmail.EditValueChanged
 Try
 Dim Emails As New List(Of String)
 Emails.Add("[email protected]")
 Emails.Add("[email protected]")
 Emails.Add("[email protected]")
 Emails.Add("[email protected]")

 Dim Txt = Trim(CStr(txtToEmail.EditValue))

 Dim Suggestions As IEnumerable(Of String)

 If Txt <> "" Then
 If Txt.IndexOf(",") = -1 Then
 Suggestions = From c In Emails Where c.StartsWith(Txt) Select c
 Else
 Dim lastIndex = Txt.LastIndexOf(",")
 Dim lastWord = Trim(Txt.Substring(lastIndex + 1))
 Suggestions = From c In Emails Where c.StartsWith (lastWord) Select c
 End If

 EmailList.Items.Clear()

 For Each r In Suggestions
 EmailList.Items.Add(r )
 Next

 End If

 If EmailList.ItemCount> 0 Then
 EmailList.Visible = True
 End If
 
 Catch ex As Exception
 ShowErrorBox(ex)
 End Try

End Sub

Private Sub EmailList_Click(ByVal sender As System.Object , ByVal e As System.EventArgs) Handles EmailList.Click
 Try
 If EmailList.SelectedValue = Nothing OrElse EmailList.SelectedValue = "" Then Return

 Dim Txt = CStr(txtToEmail .EditValue)

 If Txt.IndexOf(",") = -1 Then
 txtToEmail.EditValue = EmailList.SelectedValue
 Else
 Dim lastIndex = Txt.LastIndexOf (",")
 txtToEmail.EditValue = Txt.Substring(0, lastIndex + 1) & Ema ilList.SelectedValue
 End If

 txtToEmail.Focus()
 txtToEmail.SelectionStart = CStr(txtToEmail.EditValue).Length

 EmailList.Visible = False
 Catch ex As Exception
 ShowErrorBox(ex)
 End Try

End Sub

I am Develop an application that requires a text box with auto-completion/suggestions (drop-down) for multiple words (separated by space separators), just like the label text box in StackOverflow.

For example, I start typing “app”, it should display all the words in the suggestion list starting with app, when I enter a word and press the space bar and start typing a new word, it should display all the suggestions for that part of the word .

Is there an example I can look at?

I hope this helps.. I use the Developer Quick Tool, but it can also be used with regular .net components.

Private Sub txtToEmail_EditValueChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtToEmail.EditValueChanged
 Try
 Dim Emails As New List(Of String)
 Emails.Add("[email protected]")
 Emails.Add("[email protected]")
 Emails.Add("[email protected]") 
 Emails.Add("[email protected]")

 Dim Txt = Trim(CStr(txtToEmail.EditValue))

 Dim Suggestions As IEnumerable(Of String)

 If Txt <> "" Then
 If Txt.IndexOf(",") = -1 Then
 Suggestions = From c In Emails Where c.StartsWith(Txt ) Select c
 Else
 Dim lastIndex = Txt.LastIndexOf(",")
 Dim lastWord = Trim(Txt.Substring(lastIndex + 1))
 Suggestions = From c In Emails Where c.StartsWith(lastWord) Select c
 End If

 EmailList.Items.Clear()

 For Each r In Suggestions
 EmailList.Items.Add(r)
 Next

 End If< br />
 If EmailList.ItemCount> 0 Then
 EmailList.Visible = True
 End If

 Catch ex As Exception
 ShowErrorBox(ex)< br /> End Try

End Sub

Private Sub EmailList_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles EmailList.Click
 Try 
 If EmailList.SelectedValue = Nothing OrElse EmailList.SelectedValue = "" Then Return

 Dim Txt = CStr(txtToEmail.EditValue)

 If Txt.IndexOf(" ,") = -1 Then
 txtToEmail.EditValue = EmailList.SelectedValue
 Else
 Dim lastIndex = Txt.LastIndexOf(",")
 txtToEmail.EditValue = Txt.Substring( 0, lastIndex + 1) & EmailList.SelectedValue
 End If

 txtToEmail.Focus()
 txtToEmail.SelectionStart = CStr(txtToEmail.EditValue).Length

 EmailList.Visible = False
 Catch ex As Exception
 ShowErrorBox(ex) 
 End Try

End Sub