从下拉列表中选择项目时如何启动更改事件? [英] How to initiate on change event when selecting item from drop down list?

问题描述

我正在尝试从下拉菜单中选择货币值来触发更改时"事件.这将更新该页面上的迷你电子表格，以反映货币的价值.但是，通过VBA更改值时不会触发jscript.我正在使用IE来做到这一点.

I'm trying to trigger "on change" event upon selecting currency value from drop-down menu. This would update the mini spreadsheet on that page reflecting the value of the currency. However when changing the value through VBA jscript is not being triggered. I'm using IE to do this.

  Set objIE = New InternetExplorer
    objIE.Visible = True
    objIE.navigate "https://www.reuters.com/markets/currencies"
    Do While objIE.Busy = True Or objIE.readyState <> 4: DoEvents: Loop

    'Settlement Currency is Hard Coded to GBP
    SettCcy = "GBP"
    'Set Expression Currency
    expCcy = "EUR"
    'Set Target Currency
    targetCcy = "USD"

    On Error GoTo ResetIE

    If expCcy <> SettCcy And expCcy <> targetCcy Then

        'Set the rate refresher
        Set clicker = objIE.document.getElementsByClassName("CurrencyCalculator-currency-swap-2yw2I")(0)

        'Set the Expression Currency
        For Each o In objIE.document.getElementsByTagName("select")(1) 'Sets Expression Currency
            If o.Value = expCcy Then 
                o.Selected = True
                o.FireEvent "onchange"
                Exit For
            End If
        Next

我需要做的是，通过VBA更改值后，页面将以与手动执行时相同的方式进行更新.

All I need is that upon changing the value through VBA the page would update the same way as it would when doing it manually.

推荐答案

请尝试使用

Please try to use the dispatchEvent method to dispatch the change event to the select element, then trigger the onchange event.

下面的示例代码(您可以参考并对其进行修改，它对我而言效果很好):

Sample code as below (you could refer to it and modify it, it works well on my side):

Public Sub ClickTest()

    Dim  ie As Object, evtChange As Object

    Dim item As Object

    Set ie = CreateObject("InternetExplorer.Application")
    With ie
        .Visible = True
        .Navigate2 "<the website url>"

        While .Busy Or .readyState <> 4: DoEvents: Wend

        Set evtChange = .Document.createEvent("HTMLEvents")
        evtChange.initEvent "change", True, False

        'get the select element. Please note the index, it is starting from 0.
        Set item = ie.Document.getElementsByTagName("select")(0)

        expCcy = "EUR"

        'Set the Expression Currency
        For Each o In item 'Sets Expression Currency
            If o.Value = expCcy Then
                o.Selected = True
                o.dispatchEvent evtChange
                Exit For
            End If
        Next        
    End With
End Sub

这样的网站资源:

<select id="ddlCurrency" onchange="ddlCurrencyChange()" >
    <option value="GBP">GBP</option>
    <option value="EUR">EUR</option>
    <option value="USD">USD</option>
</select>

<script>

    function ddlCurrencyChange() {
        document.getElementById("result").innerHTML += "change event triggered... <br /> selected value is " + document.getElementById("ddlCurrency").value + "<br/>";
    }
</script>

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