我需要打印从网页下载后在IE浏览器中打开的文档（该文档页面没有检查元素选项），目前使用SendKeys可以实现打印操作，但当文件较大时，会弹出“打印进行中”的进度窗口。Application.Wait无法确定合适的等待时长，请教如何让宏暂停执行直至打印进度完成？

当前使用的打印函数 #

Function Sample(tet As Variant)
Dim IE_Tab As SHDocVw.InternetExplorer, ie As InternetExplorer
Dim HTML_Doc As MSHTML.HTMLDocument
Dim SH_Win As SHDocVw.ShellWindows, sh As Object
Dim T_Str As String
Set SH_Win = New SHDocVw.ShellWindows

 For Each IE_Tab In SH_Win
     T_Str = IE_Tab.LocationURL
       If T_Str = tet Then
         Application.Wait (Now + TimeValue("00:00:05"))
         Set sh = CreateObject("WScript.Shell")
         'this command just populates the print dialog box, it worked fine only if i print an web page here iam trying to print a document opened as IE
         IE_Tab.ExecWB OLECMDID_PRINT, OLECMDEXECOPT_DODEFAULT, 2, 0
         sh.AppActivate "Print"
         Application.Wait (Now + TimeValue("00:00:02"))
         sh.SendKeys "c", 1
         Application.Wait (Now + TimeValue("00:00:02"))
        sh.SendKeys ("{ENTER}")
         IE_Tab.Quit
            Exit For
     End If
Next
End Function

相关窗口截图 #

• 打印窗口：
  
• 打印进度窗口：
  

固定时长的Application.Wait确实不靠谱，尤其是处理大文件时，我们可以通过Windows API函数来检测“打印进行中”窗口的存在，循环等待直到该窗口消失，再继续执行后续代码。

步骤1：添加API声明 #

在VBA模块的最顶部添加以下API函数声明，用来查找系统窗口：

Private Declare PtrSafe Function FindWindow Lib "user32" Alias "FindWindowA" _
    (ByVal lpClassName As String, ByVal lpWindowName As String) As LongPtr

Private Declare PtrSafe Function FindWindowEx Lib "user32" Alias "FindWindowExA" _
    (ByVal hWnd1 As LongPtr, ByVal hWnd2 As LongPtr, ByVal lpsz1 As String, _
    ByVal lpsz2 As String) As LongPtr

注：如果使用32位Office，去掉PtrSafe并将LongPtr替换为Long即可。

步骤2：修改打印函数，添加智能等待逻辑 #

我们在发送打印确认的Enter键后，加入循环检测逻辑，直到“打印进行中”窗口消失再关闭IE标签。修改后的函数如下：

Function Sample(tet As Variant)
    Dim IE_Tab As SHDocVw.InternetExplorer, ie As InternetExplorer
    Dim HTML_Doc As MSHTML.HTMLDocument
    Dim SH_Win As SHDocVw.ShellWindows, sh As Object
    Dim T_Str As String
    Dim progressWnd As LongPtr
    
    Set SH_Win = New SHDocVw.ShellWindows

    For Each IE_Tab In SH_Win
        T_Str = IE_Tab.LocationURL
        If T_Str = tet Then
            Application.Wait (Now + TimeValue("00:00:05"))
            Set sh = CreateObject("WScript.Shell")
            
            ' 触发打印对话框
            IE_Tab.ExecWB OLECMDID_PRINT, OLECMDEXECOPT_DODEFAULT, 2, 0
            sh.AppActivate "Print"
            Application.Wait (Now + TimeValue("00:00:02"))
            sh.SendKeys "c", 1
            Application.Wait (Now + TimeValue("00:00:02"))
            sh.SendKeys "{ENTER}"
            
            ' 循环等待打印进度窗口消失
            Do
                ' 根据你的进度窗口标题查找窗口，标题不对请自行修改
                progressWnd = FindWindow(vbNullString, "打印进行中")
                ' 释放CPU资源，避免程序假死
                DoEvents
                ' 每500毫秒检测一次
                Application.Wait (Now + TimeValue("00:00:00.5"))
            Loop While progressWnd <> 0
            
            ' 打印完成后关闭IE标签
            IE_Tab.Quit
            Exit For
        End If
    Next
End Function

关键说明 #

• 如果你的打印进度窗口标题不是“打印进行中”，请替换FindWindow函数的第二个参数为实际窗口标题。
• DoEvents能让Excel在等待期间响应其他操作，避免出现程序无响应的情况。
• 500毫秒的检测间隔可以根据需要调整，既保证响应速度，又不会过度占用系统资源。

内容的提问来源于stack exchange，提问作者arun v