excel 2010视觉基础

Question

我正在尝试使用行审核中的项目组合框添加项目，并且我不断收到对象所需的错误：

Private Sub ECForm_Initialize()
    row_review = 1

    Dim TheSheet As Worksheet
    Set TheSheet = Sheets("Electrical")

    wirezsize1.Clear

    Do
        DoEvents
        row_review = row_review + 1
        item_in_review = TheSheet.Range("A" & row_review)

        If Len(item_in_review) > 0 Then wiresize1.AddItem (item_in_review)    
    Loop Until item_in_review = ""

    MsgBox "Complete"
End Sub