Add to Listbox if cell value contains specific string - excel

Question

I am trying to add data to a Listbox on a Userform, based on the value of the the Cell in column C of the range that is searched. If the cell in column C contains a certain string I would like it to be added to the Listbox.
The below code is as far as I have got but it is returning an empty Listbox with no error.
Private Sub OptionButton12_Click()
Dim I As Integer
Dim lastRow As Integer
Dim searchString As String
searchString = "LISTBOXENTRY"
With ThisWorkbook.Sheets("Sheet1")
lastRow = .Cells(.Rows.Count, "A").End(xlUp).Row
End With
Plybooks.ListBox1.Clear
For I = 1 To lastRow
If Cells(I, 3).Value = searchString Then
Plybooks.ListBox1.AddItem Range("A" & I)
End If
Next I
End Sub

Answer 1

Try using the script below and please let me know if it works!
based on your script above, I assumed some of the dataframe dimensions. please let me know if it is not correct so I can tweak it.
I assumed you are working on first sheet (sheets(1)), and col C is the column you are using for the value check against the "searchString" variable. (if true, append the value in listbox1)
Thanks
Private Sub OptionButton12_Click()
Dim lastRow As Integer
Dim searchString As String
Dim wb As Workbook
Dim sRng As Range
Dim cel As Range
'assign current wb into wb workbook object
Set wb = ThisWorkbook
'assign str you want to search into variable
searchString = "LISTBOXENTRY"
'find last row number in colC (3) using crow function. (assuming you want to do a check on every cell listed in column C)
lastRow = crow(1, 3)
plybooks.listbox1.Clear
'assign range object using dataframe dimensions based on row 1 col C (lbound), to lastrow col3 (ubound)
With wb.Sheets(1)
Set sRng = .Range(.Cells(1, 3), .Cells(trow, 3))
End With
'loops through each cel
For Each cel In sRng
If cel.Value = searchString Then
'adds item into listbox1 if conditional statement is True
plybooks.listbox1.AddItem Item:=cel.Value
Else
End If
Next cel
End Sub
Private Function crow(s As Variant, c As Integer)
crow = Sheets(s).Cells(Rows.Count, c).End(xlUp).Row
End Function

Answer 2

Added cell values in ranges over multiple sheets if cell contains certain value, using the following:
Public Sub PlybookListbox()
'Clear fields before start
Plybooks.ListBox1.MultiSelect = 0
Plybooks.ListBox1.Clear
Plybooks.ListBox1.Value = ""
Plybooks.ListBox1.MultiSelect = 2
Dim AllAreas(2) As Range, Idx As Integer, MyCell As Range, TargetRange As Range
Dim lastrowFrontWing As Long
Dim lastrowNose As Long
Dim lastrowBargeboard As Long
lastrowFrontWing = Worksheets("Front Wing").Cells(Rows.Count, 2).End(xlUp).Row
lastrowNose = Worksheets("Nose").Cells(Rows.Count, 2).End(xlUp).Row
lastrowBargeboard = Worksheets("Bargeboard & SPV").Cells(Rows.Count, 2).End(xlUp).Row
Set AllAreas(0) = Worksheets("Front Wing").Range("c6:c" & lastrowFrontWing)
Set AllAreas(1) = Worksheets("Nose").Range("c6:c" & lastrowNose)
Set AllAreas(2) = Worksheets("Bargeboard & SPV").Range("c6:c" & lastrowBargeboard)
Plybooks.ListBox1.Clear
For Idx = 0 To 2
For Each MyCell In AllAreas(Idx).Cells
If InStr(1, MyCell.Value, "(FS)") > 0 Then
Plybooks.ListBox1.AddItem MyCell.Value
End If
Next MyCell
Next Idx
End Sub