Excel Internet Explorer自动化导致IE环境崩溃

Question

I've successfully automated a VBA Excel macro to iterate through a loop and hit a series of URL's to trigger a server-side script - this is simply done with:

myIE.Navigate ("http://someURL.php?VARIABLE=" & var_string)

where var_string is assigned within the loop as it iterates through. Before this, I've cleared cache, cookies and history with:

Shell "RunDll32.exe InetCpl.cpl,ClearMyTracksByProcess #

I've tried many #'s including 8,2, 16 etc to see if any of these had an effect (and combination of #'s).

The issue I am having, is that although the entire script SOMETIMES works, if I were to run it a second time the line where I navigate to the URL fails to call the URL even though the domain/URL is fully live and functional. Any other URL I manually type into the IE window works just fine - just not the one I am calling inside the loop. IE is locking me out of that domain temporarily. If I come back to the script a few hours from last running it, it generally works.

Again the domain is functional and script is fine - I verify it all the time with another machine.

It's as if I am setting something environmentally and breaking Internet Explorer within VBA even though the script is absurdly simple.

I've tried CreateObject() , GetObject as well as InternetExplorerMedium for myIE object.

Answer 1

If all you need is to "touch" that URL for its side effects, you can as well use a XMLHTTP object. In VBA, go to menu Tools, then References and choose Microsoft XML, v6.0. Then:

Dim Request As New XMLHTTP
Request.open "GET", Url & "?VARIABLE=" & var_string, False
Request.send
' Check Request.status, probably for 200

Some notes:

• You may want to use POST instead of GET, if you're having problems with caching
• You should pass the data in the POST body, if the server can handle it
• The value of var_string should be escaped, in this case, URL encoded
• If you don't want to block waiting for responses, you can make requests asynchronously ( True third argument to open )

Following these notes, here's a more elaborate example:

Dim Request As New XMLHTTP
Request.open "POST", Url, True
Dim Handler As New CXMLHTTPHandler
Handler.Initialize Request
Set Request.onreadystatechange = Handler
Request.setRequestHeader "Content-Type", "application/x-www-form-urlencoded"    
Request.send UrlEncode("VARIABLE") & "=" & UrlEncode(var_string)
' This returns immediately, the check must now be done in the Handler

For the missing pieces, here's the code for CXMLHTTPHandler , which I actually found through stackoverflow , and a definition of UrlEncode at stackoverflow .

You should specialize CXMLHTTPHandler for your needs, probably even make it accept an AddressOf a procedure and call it in the actual default procedure. The default procedure should set the m_xmlHttp to Nothing when m_xmlHttp.readyState is 4 .

---

EDIT 1: If your request code is in a loop, you need to break the Dim ... New statements in two, to ensure you're using fresh objects:

Dim Request As XMLHTTP
Set Request = New XMLHTTP
Request.open "POST", Url, True
Dim Handler As CXMLHTTPHandler
Set Handler = New CXMLHTTPHandler
Handler.Initialize Request
Set Request.onreadystatechange = Handler
Request.setRequestHeader "Content-Type", "application/x-www-form-urlencoded"    
Request.send UrlEncode("VARIABLE") & "=" & UrlEncode(var_string)
' This returns immediately, the check must now be done in the Handler