关闭PDF文件

Question

我使用此代码将工作表导出为PDF文件。

我想添加一个代码来测试文件是否已经打开，如果是，请关闭它然后导出另一个。

Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long

Sub Preview_Letter()
Application.ScreenUpdating = False

Sheet7.Visible = xlSheetVisible

Sheet7.Select

Dim File As String

File = ActiveWorkbook.Path & "\Letters\Preview.pdf"

If Not IsFileOpen(File) Then
    ActiveSheet.ExportAsFixedFormat Type:=xlTypePDF, FileName:=File
    Else

    ActiveSheet.ExportAsFixedFormat Type:=xlTypePDF, FileName:=File
    GoTo 1
    Exit Sub
End If

1: Sheet7.Visible = xlSheetHidden

Sheet8.Activate
Sheet8.Range("A1").Select

Application.ScreenUpdating = True

ShellExecute 0, "Open", File, "", "", vbNormalNoFocus
End Sub

有没有办法关闭PDF文件（不终止Adobe Reader）??

谢谢你。