VBA 查找函数无法从循环外部拉取字符串

Question

我正在编写代码来转换同一文件夹内多个工作簿中的温度数据 - 数据看起来像这样，只是作为工作表：

Site Id Date    TMAX.D-1 (degC)     TMIN.D-1 (degC)     WSPDV.D-1 (mph)     RHENC.D-1 (pct)     LRADT.D-1 (lang) 
2031    5/5/2019    21.6    5   6.1 64  382.83
2031    5/6/2019    25.9    13  8.8 68  348.68
2031    5/7/2019    17.3    9.4 9   70  258.88

用户选择是否需要转换温度（如果 TC = 1 则将“是/否”答案拉到问题消息框），然后给我要保存为字符串的列标题：

    If TC = 1 Then
        Dim RawTemp_max As String
        Dim RawTemp_min As String
        Dim TempUnits As String
        RawTemp_max = Application.InputBox("Type or copy in the column label of your maximum temperature data", "Data Select", Type:=2)
        RawTemp_min = Application.InputBox("Type or copy in the column label of your minimum temperature data", "Data Select", Type:=2)
        TempUnits = Application.InputBox("Type the UNITS your temperature data is in, exactly as seen here: F, K", "Units", Type:=2)

到目前为止一切顺利——列标题在所有工作簿中都是一致的，因此这不应该导致问题。然后我有一个循环依次打开每个工作簿，找到温度列，添加新列并执行计算（myFile 在子文件的开头定义，不包含在这里，它是要打开的文件）：

'Loop through each Excel file in folder
  Do While myFile <> ""

        Workbooks.Open FileName:=(myPath & myFile)
        Set wb = ActiveWorkbook
        Dim bname As String * 5
        bname = wb.name
        Dim ws As Worksheet
        Set ws = wb.Sheets(1)
        DoEvents

    'Setup for all
        Dim LastRow As Long
        LastRow = Cells(Rows.Count, "A").End(xlUp).Row

    'Temperature
        If TC = 1 Then
           Dim MaxTemp As Range
           Dim MinTemp As Range
           Dim xT As Range
           Dim nT As Range
           Dim NewMax As Range
           Dim NewMin As Range
           With ws.UsedRange
                Set xT = .Find(RawTemp_max, LookIn:=xlValues, lookAt:=xlWhole)
                If Not xT Is Nothing Then
                    Set MaxTemp = Range(Cells(1, xT.Column), Cells(LastRow, xT.Column))
                    MaxTemp.EntireColumn.Offset(0, 2).Insert
                    Set NewMax = Range(Cells(2, MaxTemp.Column + 1), Cells(LastRow, MaxTemp.Column + 1))
                End If
           End With
        End If
   Loop

似乎无法在 <.Find(RawTemp, LookIn:=xlValues)> 函数中找到 RawTemp 指定的温度列，因为当我尝试设置范围时，它在下一行不断给我一个“错误 91：未设置对象变量或 With 块变量”。我尝试使用 xT.select 进行故障排除，但它根本找不到单元格。

我尝试不使用 With 块（编码为 ws.Find(RawTemp, LookIn:=xlValues)）并得到相同的错误。您不能将字符串传递到循环中吗？我已经检查过，字符串和列标题之间不应该不匹配。

谢谢！