VBA 关闭来自 Excel 的 PDF 文档
VBA to Close a PDF Document from Excel
我有一个可爱的小程序，它可以关闭带有 Acrobat 显示的 window 或只关闭其中的一个文档。只有设计是我自己设计的，这意味着我不完全理解代码，但我知道它只能部分工作。它会完全退出 Adobe Acrobat，无论显示多少文档，但它不能只关闭一个（因为转录它的原件声称它可以而且应该）。
Private Sub CloseReaderDC(Optional ByVal MailIdx As Integer)
Dim WinId As String
Dim Wnd As LongPtr
If MailIdx Then
WinId = AcrobatWindowID(Mail(MailIdx))
Wnd = FindWindow(vbNullString, WinId)
PostMessage Wnd, WM_CLOSE, 0, ByVal 0&
Else
WinId = AcrobatWindowID
Wnd = FindWindow(WinId, vbNullString)
SendMessage Wnd, WM_CLOSE, 0, ByVal 0&
End If
End Sub
逻辑是参数MailIdx标识了一个文件名，足以找到一个top window。如果没有给出任何值，应用程序应该被关闭。这部分有效。另一部分也有效，但前提是打开了一个文档，在这种情况下关闭的不是文档而是整个应用程序。我相信这次关闭可能是由 Acrobat Reader 本身引起的，它没有看到在没有文档可显示的情况下保持打开状态的原因。我还认为，如果有多个文档，可能找不到 window 句柄，因为 FindWindow 仅找到顶部 window，而我要关闭的是第二个。在实践中，我尝试了两种方法，在打开另一个之前和之后关闭现有的。在一种情况下应用程序被关闭，在另一种情况下没有任何反应。
我不知道为什么我的导师在一种情况下使用SendMessage而在另一种情况下使用PostMessage。我也不知道我要找的 window 是否是 Child Window 或者如果是的话如何处理它。有什么建议吗？
编辑 2021 年 1 月 11 日
我使用以下代码来测试@FaneDuru 的解决方案。
Private Sub Test_CloseReaderDC()
ReDim Mail(2)
Mail(0) = ""
Mail(1) = "File1.PDF"
Mail(2) = "File2.PDF"
CloseReaderDC 1
End Sub
Private Sub CloseReaderDC(Optional ByVal MailIdx As Integer)
' NIC 003 ++ 10 Jan 2021
Dim WinTitle As String
Dim WinCap As String
Dim Wnd As LongPtr
WinTitle = AcrobatWindowID
If MailIdx Then
WinCap = AcrobatWindowID(Mail(MailIdx))
Wnd = FindWindow(vbNullString, WinCap)
Debug.Print Wnd
SendMessage Wnd, WM_CloseClick, 6038, ByVal 0&
Else
Wnd = FindWindow(WinTitle, vbNullString)
Debug.Print Wnd
SendMessage Wnd, WM_CLOSE, 0, ByVal 0&
End If
End Sub
Function AcrobatWindowID(Optional ByVal Wn As String)
' NIC 003 ++ 07 Jan 2021
Dim Fun As Boolean
Fun = CBool(Len(Wn))
If Fun Then Wn = Wn & " - "
AcrobatWindowID = Wn & Split("AcrobatSDIWindow,Adobe Acrobat Reader DC", ",")(Abs(Fun))
End Function
该代码对 1 个或 2 个文件都非常有效，直到使用参数 0 调用时才关闭应用程序。但是第二次尝试找不到 window，因此没有采取任何措施。
我启动了 Acrobat 并从文件>打开菜单中选择了之前打开的 2 个文件。 File1 在第一个选项卡中，File2 在第二个选项卡中，处于活动状态。然后我试图删除失败的 File1。然后我用 2 作为参数调用了关闭顶层文件的代码。此后，代码找到 File1 的 window 并将其关闭。
但是，我认为明显的规则并没有得到始终如一的遵循。文件的打开方式似乎有所不同。在我的项目中，文件是通过超链接打开的，一次一个。因此，我的上述测试并不能说明 FaneDuru 的建议如何在我的项目中发挥作用，但它证明该解决方案有效。
关于我关于通过以编程方式按下“文件”菜单的“关闭文件”控件来关闭活动文档的评论，您没有说任何话...
这种关闭方式不会使 Acrobat 应用程序退出。它保持打开状态，即使在 运行 代码的那一刻只打开了一个文档。
所以，请测试下一行代码。您需要 Acrobat Reader DC 处理程序和必要的参数，如下所示：
Const WM_CloseClick = &H111
SendMessage Wnd, WM_CloseClick, 6038, ByVal 0&
6038 是 'Close File' 文件菜单控件 ID。
我可以使用下一个函数来确定它：
Private Function findControlID(mainWHwnd As LongPtr, ctlNo As Long) As Long
Dim aMenu As LongPtr, sMenu As LongPtr
aMenu = GetMenu(mainWHwnd): Debug.Print "Main menu = " & Hex(aMenu)
sMenu = GetSubMenu(aMenu, 0&): Debug.Print "File menu = " & Hex(sMenu)
mCount = GetMenuItemCount(sMenu): Debug.Print "File menu no of controls: " & mCount 'check if it is 28
findControlID = GetMenuItemID(sMenu, ctlNo - 1) 'Menu controls are counted starting from 0
End Function
上面的函数是这样调用的：
Sub testFindCloseControlID()
Dim Wnd As LongPtr
'Wnd = findWindowByPartialTitle("Adobe Acrobat Reader DC") 'you will obtain it in your way
Debug.Print findControlID(Wnd, 15) '15 means the fiftheenth control of the File menu (0)
End Sub
15 也算上水平控件分隔符。
为了找到“Adobe Acrobat Reader DC”window 处理程序我使用了上面提到的函数，但这并没有太大关系。你可以用你的方式来判断...
请测试以上方法并发表评论
已编辑:
为了提取应用程序菜单标题，我使用了下一个声明：
Option Explicit
'APIs for identify a window handler
Private Declare PtrSafe Function FindWindow Lib "user32" Alias "FindWindowA" _
(ByVal lpClassName As String, ByVal lpWindowName As String) As LongPtr
Private Declare PtrSafe Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLengthA" (ByVal hwnd As LongPtr) As Long
Private Declare PtrSafe Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hwnd As LongPtr, _
ByVal lpString As String, ByVal cch As Long) As Long
Private Declare PtrSafe Function GetWindow Lib "user32" (ByVal hwnd As LongPtr, ByVal wCmd As Long) As Long
'____________________________________________________
'Menu related APIs
Private Declare PtrSafe Function GetMenu Lib "user32.dll" (ByVal hwnd As LongPtr) As LongPtr
Private Declare PtrSafe Function GetSubMenu Lib "user32" (ByVal hMenu As LongPtr, ByVal nPos As Long) As LongPtr
Private Declare PtrSafe Function GetMenuItemID Lib "user32" _
(ByVal hMenu As LongPtr, ByVal nPos As Long) As Long
Private Declare PtrSafe Function GetMenuItemCount Lib "user32" (ByVal hMenu As LongPtr) As Long
Private Declare PtrSafe Function GetMenuItemInfo Lib "user32" Alias "GetMenuItemInfoA" (ByVal hMenu As LongPtr, _
ByVal Un As Long, ByVal b As Long, lpMenuItemInfo As MENUITEMINFO) As Long
Private Declare PtrSafe Function GetMenuString Lib "user32" Alias "GetMenuStringA" (ByVal hMenu As LongPtr, _
ByVal wIDItem As Long, ByVal lpString As String, ByVal nMaxCount As Long, ByVal wFlag As Long) As Long
'_____________________________________________________
Private Type MENUITEMINFO
cbSize As Long
fMask As Long
fType As Long
fState As Long
wID As Long
hSubMenu As LongPtr
hbmpChecked As LongPtr
hbmpUnchecked As LongPtr
dwItemData As LongPtr
dwTypeData As String
cch As Long
hbmpItem As LongPtr
End Type
Private Const GW_HWNDNEXT = 2
下一个functions/subs：
要找到任何只知道其部分标题的 window：
Sub testFindWindByPartTitle()
Debug.Print findWindowByPartialTitle("Notepad")
End Sub
Private Function findWindowByPartialTitle(ByVal sCaption As String, Optional strSecond As String) As LongPtr
Dim lhWndP As LongPtr
Dim sStr As String
findWindowByPartialTitle = CLngPtr(0)
lhWndP = FindWindow(vbNullString, vbNullString) 'PARENT WINDOW
Do While lhWndP <> 0
sStr = String(GetWindowTextLength(lhWndP) + 1, Chr$(0))
GetWindowText lhWndP, sStr, Len(sStr)
If Len(sStr) > 0 Then sStr = left$(sStr, Len(sStr) - 1)
If InStr(1, sStr, sCaption) > 0 And _
IIf(strSecond <> "", InStr(1, sStr, strSecond) > 0, 1 = 1) Then
findWindowByPartialTitle = lhWndP
Exit Do
End If
lhWndP = GetWindow(lhWndP, GW_HWNDNEXT)
Loop
End Function
一个通过控件标题提取必要ID的版本，但是它只适用于记事本:
Private Sub TestfindMenuItemsByCaption()
Const NotePApp As String = "Notepad"
Debug.Print findMenuIDByString(NotePApp, "Save") 'it does work
Const pdfApp As String = "Adobe Acrobat Reader DC"
Debug.Print findMenuIDByString(pdfApp, "Close") 'it does not work
End Sub
Private Function findMenuIDByString(pdfApp As String, searchString As String) As Long
Dim mainWHwnd As LongPtr, aMenu As LongPtr, mCount As Long
Dim LookFor As Long, sMenu As LongPtr, sCount As Long
Dim LookSub As Long, sID As Long, sString As String
mainWHwnd = findWindowByPartialTitle(pdfApp)
aMenu = GetMenu(mainWHwnd): Debug.Print "Main menu = " & Hex(aMenu)
sMenu = GetSubMenu(aMenu, 0): Debug.Print "File menu = " & Hex(sMenu)
sCount& = GetMenuItemCount(sMenu)
For LookSub& = 0 To sCount& - 1
sID& = GetMenuItemID(sMenu, LookSub&): Debug.Print "ID = " & sID: 'Stop
sString$ = String$(100, " ")
Call GetMenuString(sMenu, sID&, sString$, 100&, 1&) ' 1&)
Debug.Print sString$ ': Stop
If InStr(LCase(sString$), LCase(searchString$)) Then
findMenuIDByString = sID
Exit Function
End If
Next LookSub&
End Function
还有第二个版本，不幸的是，它的工作方式完全相同。我的意思是，仅为记事本返回 ID：
Private Sub TestfindMenuItemsByCaptionBis()
Const NotePApp As String = "Notepad"
Debug.Print findMenuItemIDByCaption(NotePApp, "Save")
Const pdfApp As String = "Adobe Acrobat Reader DC"
Debug.Print findMenuItemIDByCaption(pdfApp, "Close")
End Sub
Private Function findMenuItemIDByCaption(strApp As String, strCaption As String)
Dim appHwnd As LongPtr, hMenu As LongPtr, fMenu As LongPtr, i As Long
Dim retval As Long, mii As MENUITEMINFO 'mii receives information about each item
Const WM_SaveClick = &H111, MIIM_STATE = &H1, MIIM_STRING = &H40&, MIIM_ID = &H2&, MIIM_CHECKMARKS = &H8&
Const MIIM_SUBMENU = &H4&, MIIM_TYPE = &H10, MIIM_FTYPE = &H100&, MIIM_DATA = &H20&
appHwnd = findWindowByPartialTitle(strApp)
If appHwnd = 0 Then MsgBox "No application window found...": Exit Function
hMenu = GetMenu(appHwnd) 'application window Menu
fMenu = GetSubMenu(hMenu, 0) 'app window 'File' Submenu
For i = 0 To GetMenuItemCount(fMenu)
With mii
.cbSize = Len(mii)
.fMask = MIIM_STATE Or MIIM_SUBMENU Or MIIM_TYPE
.dwTypeData = space(256)
.cch = 256
retval = GetMenuItemInfo(fMenu, i, 1, mii) '2 = the third menu item
Debug.Print left(.dwTypeData, .cch)
If InStr(left(.dwTypeData, .cch), strCaption) > 0 Then
findMenuItemIDByCaption = GetMenuItemID(fMenu, i): Exit Function
End If
End With
Next i
End Function
我尝试了我能找到的所有常量，但没有成功...如果我们找到一种方法，子程序也可以读取最近的文件列表并激活所需的文件，如果不是活动的是必须的。
我有一个可爱的小程序，它可以关闭带有 Acrobat 显示的 window 或只关闭其中的一个文档。只有设计是我自己设计的，这意味着我不完全理解代码，但我知道它只能部分工作。它会完全退出 Adobe Acrobat，无论显示多少文档，但它不能只关闭一个（因为转录它的原件声称它可以而且应该）。
Private Sub CloseReaderDC(Optional ByVal MailIdx As Integer)
Dim WinId As String
Dim Wnd As LongPtr
If MailIdx Then
WinId = AcrobatWindowID(Mail(MailIdx))
Wnd = FindWindow(vbNullString, WinId)
PostMessage Wnd, WM_CLOSE, 0, ByVal 0&
Else
WinId = AcrobatWindowID
Wnd = FindWindow(WinId, vbNullString)
SendMessage Wnd, WM_CLOSE, 0, ByVal 0&
End If
End Sub
逻辑是参数MailIdx标识了一个文件名，足以找到一个top window。如果没有给出任何值，应用程序应该被关闭。这部分有效。另一部分也有效，但前提是打开了一个文档，在这种情况下关闭的不是文档而是整个应用程序。我相信这次关闭可能是由 Acrobat Reader 本身引起的，它没有看到在没有文档可显示的情况下保持打开状态的原因。我还认为，如果有多个文档，可能找不到 window 句柄，因为 FindWindow 仅找到顶部 window，而我要关闭的是第二个。在实践中，我尝试了两种方法，在打开另一个之前和之后关闭现有的。在一种情况下应用程序被关闭，在另一种情况下没有任何反应。
我不知道为什么我的导师在一种情况下使用SendMessage而在另一种情况下使用PostMessage。我也不知道我要找的 window 是否是 Child Window 或者如果是的话如何处理它。有什么建议吗？
编辑 2021 年 1 月 11 日
我使用以下代码来测试@FaneDuru 的解决方案。
Private Sub Test_CloseReaderDC()
ReDim Mail(2)
Mail(0) = ""
Mail(1) = "File1.PDF"
Mail(2) = "File2.PDF"
CloseReaderDC 1
End Sub
Private Sub CloseReaderDC(Optional ByVal MailIdx As Integer)
' NIC 003 ++ 10 Jan 2021
Dim WinTitle As String
Dim WinCap As String
Dim Wnd As LongPtr
WinTitle = AcrobatWindowID
If MailIdx Then
WinCap = AcrobatWindowID(Mail(MailIdx))
Wnd = FindWindow(vbNullString, WinCap)
Debug.Print Wnd
SendMessage Wnd, WM_CloseClick, 6038, ByVal 0&
Else
Wnd = FindWindow(WinTitle, vbNullString)
Debug.Print Wnd
SendMessage Wnd, WM_CLOSE, 0, ByVal 0&
End If
End Sub
Function AcrobatWindowID(Optional ByVal Wn As String)
' NIC 003 ++ 07 Jan 2021
Dim Fun As Boolean
Fun = CBool(Len(Wn))
If Fun Then Wn = Wn & " - "
AcrobatWindowID = Wn & Split("AcrobatSDIWindow,Adobe Acrobat Reader DC", ",")(Abs(Fun))
End Function
该代码对 1 个或 2 个文件都非常有效，直到使用参数 0 调用时才关闭应用程序。但是第二次尝试找不到 window，因此没有采取任何措施。
我启动了 Acrobat 并从文件>打开菜单中选择了之前打开的 2 个文件。 File1 在第一个选项卡中，File2 在第二个选项卡中，处于活动状态。然后我试图删除失败的 File1。然后我用 2 作为参数调用了关闭顶层文件的代码。此后，代码找到 File1 的 window 并将其关闭。
但是，我认为明显的规则并没有得到始终如一的遵循。文件的打开方式似乎有所不同。在我的项目中，文件是通过超链接打开的，一次一个。因此，我的上述测试并不能说明 FaneDuru 的建议如何在我的项目中发挥作用，但它证明该解决方案有效。
关于我关于通过以编程方式按下“文件”菜单的“关闭文件”控件来关闭活动文档的评论，您没有说任何话...
这种关闭方式不会使 Acrobat 应用程序退出。它保持打开状态，即使在 运行 代码的那一刻只打开了一个文档。
所以，请测试下一行代码。您需要 Acrobat Reader DC 处理程序和必要的参数，如下所示：
Const WM_CloseClick = &H111
SendMessage Wnd, WM_CloseClick, 6038, ByVal 0&
6038 是 'Close File' 文件菜单控件 ID。
我可以使用下一个函数来确定它：
Private Function findControlID(mainWHwnd As LongPtr, ctlNo As Long) As Long
Dim aMenu As LongPtr, sMenu As LongPtr
aMenu = GetMenu(mainWHwnd): Debug.Print "Main menu = " & Hex(aMenu)
sMenu = GetSubMenu(aMenu, 0&): Debug.Print "File menu = " & Hex(sMenu)
mCount = GetMenuItemCount(sMenu): Debug.Print "File menu no of controls: " & mCount 'check if it is 28
findControlID = GetMenuItemID(sMenu, ctlNo - 1) 'Menu controls are counted starting from 0
End Function
上面的函数是这样调用的：
Sub testFindCloseControlID()
Dim Wnd As LongPtr
'Wnd = findWindowByPartialTitle("Adobe Acrobat Reader DC") 'you will obtain it in your way
Debug.Print findControlID(Wnd, 15) '15 means the fiftheenth control of the File menu (0)
End Sub
15 也算上水平控件分隔符。
为了找到“Adobe Acrobat Reader DC”window 处理程序我使用了上面提到的函数，但这并没有太大关系。你可以用你的方式来判断...
请测试以上方法并发表评论
已编辑:
为了提取应用程序菜单标题，我使用了下一个声明：
Option Explicit
'APIs for identify a window handler
Private Declare PtrSafe Function FindWindow Lib "user32" Alias "FindWindowA" _
(ByVal lpClassName As String, ByVal lpWindowName As String) As LongPtr
Private Declare PtrSafe Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLengthA" (ByVal hwnd As LongPtr) As Long
Private Declare PtrSafe Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hwnd As LongPtr, _
ByVal lpString As String, ByVal cch As Long) As Long
Private Declare PtrSafe Function GetWindow Lib "user32" (ByVal hwnd As LongPtr, ByVal wCmd As Long) As Long
'____________________________________________________
'Menu related APIs
Private Declare PtrSafe Function GetMenu Lib "user32.dll" (ByVal hwnd As LongPtr) As LongPtr
Private Declare PtrSafe Function GetSubMenu Lib "user32" (ByVal hMenu As LongPtr, ByVal nPos As Long) As LongPtr
Private Declare PtrSafe Function GetMenuItemID Lib "user32" _
(ByVal hMenu As LongPtr, ByVal nPos As Long) As Long
Private Declare PtrSafe Function GetMenuItemCount Lib "user32" (ByVal hMenu As LongPtr) As Long
Private Declare PtrSafe Function GetMenuItemInfo Lib "user32" Alias "GetMenuItemInfoA" (ByVal hMenu As LongPtr, _
ByVal Un As Long, ByVal b As Long, lpMenuItemInfo As MENUITEMINFO) As Long
Private Declare PtrSafe Function GetMenuString Lib "user32" Alias "GetMenuStringA" (ByVal hMenu As LongPtr, _
ByVal wIDItem As Long, ByVal lpString As String, ByVal nMaxCount As Long, ByVal wFlag As Long) As Long
'_____________________________________________________
Private Type MENUITEMINFO
cbSize As Long
fMask As Long
fType As Long
fState As Long
wID As Long
hSubMenu As LongPtr
hbmpChecked As LongPtr
hbmpUnchecked As LongPtr
dwItemData As LongPtr
dwTypeData As String
cch As Long
hbmpItem As LongPtr
End Type
Private Const GW_HWNDNEXT = 2
下一个functions/subs：
要找到任何只知道其部分标题的 window：
Sub testFindWindByPartTitle()
Debug.Print findWindowByPartialTitle("Notepad")
End Sub
Private Function findWindowByPartialTitle(ByVal sCaption As String, Optional strSecond As String) As LongPtr
Dim lhWndP As LongPtr
Dim sStr As String
findWindowByPartialTitle = CLngPtr(0)
lhWndP = FindWindow(vbNullString, vbNullString) 'PARENT WINDOW
Do While lhWndP <> 0
sStr = String(GetWindowTextLength(lhWndP) + 1, Chr$(0))
GetWindowText lhWndP, sStr, Len(sStr)
If Len(sStr) > 0 Then sStr = left$(sStr, Len(sStr) - 1)
If InStr(1, sStr, sCaption) > 0 And _
IIf(strSecond <> "", InStr(1, sStr, strSecond) > 0, 1 = 1) Then
findWindowByPartialTitle = lhWndP
Exit Do
End If
lhWndP = GetWindow(lhWndP, GW_HWNDNEXT)
Loop
End Function
一个通过控件标题提取必要ID的版本，但是它只适用于记事本:
Private Sub TestfindMenuItemsByCaption()
Const NotePApp As String = "Notepad"
Debug.Print findMenuIDByString(NotePApp, "Save") 'it does work
Const pdfApp As String = "Adobe Acrobat Reader DC"
Debug.Print findMenuIDByString(pdfApp, "Close") 'it does not work
End Sub
Private Function findMenuIDByString(pdfApp As String, searchString As String) As Long
Dim mainWHwnd As LongPtr, aMenu As LongPtr, mCount As Long
Dim LookFor As Long, sMenu As LongPtr, sCount As Long
Dim LookSub As Long, sID As Long, sString As String
mainWHwnd = findWindowByPartialTitle(pdfApp)
aMenu = GetMenu(mainWHwnd): Debug.Print "Main menu = " & Hex(aMenu)
sMenu = GetSubMenu(aMenu, 0): Debug.Print "File menu = " & Hex(sMenu)
sCount& = GetMenuItemCount(sMenu)
For LookSub& = 0 To sCount& - 1
sID& = GetMenuItemID(sMenu, LookSub&): Debug.Print "ID = " & sID: 'Stop
sString$ = String$(100, " ")
Call GetMenuString(sMenu, sID&, sString$, 100&, 1&) ' 1&)
Debug.Print sString$ ': Stop
If InStr(LCase(sString$), LCase(searchString$)) Then
findMenuIDByString = sID
Exit Function
End If
Next LookSub&
End Function
还有第二个版本，不幸的是，它的工作方式完全相同。我的意思是，仅为记事本返回 ID：
Private Sub TestfindMenuItemsByCaptionBis()
Const NotePApp As String = "Notepad"
Debug.Print findMenuItemIDByCaption(NotePApp, "Save")
Const pdfApp As String = "Adobe Acrobat Reader DC"
Debug.Print findMenuItemIDByCaption(pdfApp, "Close")
End Sub
Private Function findMenuItemIDByCaption(strApp As String, strCaption As String)
Dim appHwnd As LongPtr, hMenu As LongPtr, fMenu As LongPtr, i As Long
Dim retval As Long, mii As MENUITEMINFO 'mii receives information about each item
Const WM_SaveClick = &H111, MIIM_STATE = &H1, MIIM_STRING = &H40&, MIIM_ID = &H2&, MIIM_CHECKMARKS = &H8&
Const MIIM_SUBMENU = &H4&, MIIM_TYPE = &H10, MIIM_FTYPE = &H100&, MIIM_DATA = &H20&
appHwnd = findWindowByPartialTitle(strApp)
If appHwnd = 0 Then MsgBox "No application window found...": Exit Function
hMenu = GetMenu(appHwnd) 'application window Menu
fMenu = GetSubMenu(hMenu, 0) 'app window 'File' Submenu
For i = 0 To GetMenuItemCount(fMenu)
With mii
.cbSize = Len(mii)
.fMask = MIIM_STATE Or MIIM_SUBMENU Or MIIM_TYPE
.dwTypeData = space(256)
.cch = 256
retval = GetMenuItemInfo(fMenu, i, 1, mii) '2 = the third menu item
Debug.Print left(.dwTypeData, .cch)
If InStr(left(.dwTypeData, .cch), strCaption) > 0 Then
findMenuItemIDByCaption = GetMenuItemID(fMenu, i): Exit Function
End If
End With
Next i
End Function
我尝试了我能找到的所有常量，但没有成功...如果我们找到一种方法，子程序也可以读取最近的文件列表并激活所需的文件，如果不是活动的是必须的。