如何在XMLHTTP onTimeOut时VBA回调函数？ [英] How to VBA callback function when XMLHTTP onTimeOut?

问题描述

我尝试从webserver到excel获取xml数据，然后我写了一个 sendRequest 函数调用excel

= sendRequest（http://abb.com/index.php?id=111）

当web服务器有麻烦，不能连接或找不到，excel没有反应，这是可怕的！为了避免它，我想我们应该设置timeOut。这些是我的函数：

 函数sendRequest（Url）
调用服务
设置XMLHTTP = CreateObject Msxml2.ServerXMLHTTP.6.0）
 
'超时值以毫秒为单位
 lResolve = 10 * 1000 
 lConnect = 10 * 1000 
 lSend = 10 * 1000 
 lReceive = 15 * 1000'从服务器接收数据的等待时间
 XMLHTTP.setTimeOuts lResolve，lConnect，lSend，lReceive 
 
 XMLHTTP.OnTimeOut = OnTimeOutMessage'回调函数
 
 XMLHTTP.OpenGET，Url，False 
 
错误恢复下一个
 XMLHTTP.Send 
错误时转到0 
 
 sendRequest =（XMLHTTP.responseText）
结束函数
 
私有函数OnTimeOutMessage（）
'Application.Caller.Value =服务器错误：请求超时
 MsgBox（服务器错误：请求超时）
结束函数
  

当发生 XMLHTTP 的超时时，将执行事件 OnTimeOutMessage （引用＃1 ，＃2 ）。但是，在我的测试中， OnTimeOutMessage 在 sendRequest（）开始执行

>解决方案

行;

XMLHTTP.OnTimeOut = OnTimeOutMessage

不是方法分配;而是立即执行 OnTimeOutMessage（）（并将其无用的返回值分配给 OnTimeOut ）。

根据您的示例链接， JavaScript 中的等价行正确地将 Function 对象分配给



但是，你可以捕获 .send 或使用早期绑定， WithEvents ，&内联事件处理程序。

I'm trying get xml data from webserver to excel, then I wrote a sendRequest function to call in excel

=sendRequest("http://abb.com/index.php?id=111")

When web-server having trouble, cannot connect or cannot find, excel is not responding, it was horrible! To avoid it, i think we should set timeOut. These are my function:

Function sendRequest(Url)
    'Call service
    Set XMLHTTP = CreateObject("Msxml2.ServerXMLHTTP.6.0")

    'Timeout values are in milli-seconds
    lResolve = 10 * 1000
    lConnect = 10 * 1000
    lSend = 10 * 1000
    lReceive = 15 * 1000 'waiting time to receive data from server
    XMLHTTP.setTimeOuts lResolve, lConnect, lSend, lReceive

    XMLHTTP.OnTimeOut = OnTimeOutMessage 'callback function

    XMLHTTP.Open "GET", Url, False

    On Error Resume Next
    XMLHTTP.Send
    On Error GoTo 0

    sendRequest = (XMLHTTP.responseText)
End Function

Private Function OnTimeOutMessage()
    'Application.Caller.Value = "Server error: request time-out"
    MsgBox ("Server error: request time-out")
End Function

Normally, when XMLHTTP's timeout occurs, event OnTimeOutMessage will be executed (reference #1, #2). But as in my test, OnTimeOutMessage is executed right at the beginning of sendRequest()

How to use callback function when Msxml2.ServerXMLHTTP.6.0 request is time-out?

Thank for your help!

解决方案

The line;

XMLHTTP.OnTimeOut = OnTimeOutMessage

Is not a method assignment; rather it immediately executes OnTimeOutMessage() (and assigns its useless return value to OnTimeOut).

The equivalent line in JavaScript as per your example link correctly assigns a Function object to OnTimeOut for subsequent invokation - this is not supported by VBA.

Instead, you could trap the timeout error raised after .send or use early binding, WithEvents, & inline event handlers.

这篇关于如何在XMLHTTP onTimeOut时VBA回调函数？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！