各位高手，请帮忙解决如下问题，多谢！VBA:Run-time error 13:Type mismatch when using CountIf()

[xukaili]

各位高手，请帮忙解决如下问题，多谢！

程序如下： Dim myWorkbook As Excel.Application
Set myWorkbook = New Excel.Application
myWorkbook.Workbooks.Open ("workbookName")

Dim mySheet As Excel.Worksheet
Set mySheet = myWorkbook.sheets("sheet1")


Dim rangeTest As Excel.range
Dim minTest As Variant
Dim maxTest As Variant
Dim countTest As Double

Set rangeTest = mySheet.range(mySheet.Cells(1, 1), mySheet.Cells(10, 1))
countTest = Application.WorksheetFunction.CountIf(rangeTest, ">0")
maxTest = CVar(Application.WorksheetFunction.Max(mySheet.range(mySheet.Cells(1, 1), mySheet.Cells(10, 1))))

问题(1) 在运行至:Application.WorksheetFunction.CountIf(rangeTest, ">0")，出现如下错误：
Run-time error '13':
Type mismatch
而Application.WorksheetFunction.Max()可以正确运行。

问题(2)
Set mySheet = ActiveWorkbook.Worksheets(1)
Set rangeTest = mySheet.range(mySheet.Cells(1, 1), mySheet.Cells(10, 1))
countTest = Application.WorksheetFunction.CountIf(rangeTest, ">0")
如果将mySheet和rangeTest重新赋值，CountIf也可以正确运行。

求教：如何能使问题（1）中的CountIf正确运行，多谢！！！