Question

在这里回答我自己的问题我已经在Excel VBA中使用JSON做了一些工作，并发布了大量的发现，我将在Q＆amp;格式 https://stackoverflow.com/help/self-answer http://blog.stackoverflow.com/2011/07/its-ok-to-ask-and-answer-your-own-questions/

所以在stackoverflow的其他地方，人们可以看到有关在VBA中解析JSON的问题但他们似乎错过了一两招。

首先，我不再使用自定义JSON解析库，而是使用ScriptControl的Eval方法作为我所有JSON代码的基础。此外，我们还表达了对本机Microsoft解决方案的偏好。

以下是此问题构建的先前问题In Excel VBA on Windows, how to mitigate issue of dot syntax traversal of parsed JSON broken by IDE's capitalisation behaviour?。它显示了如何使用VBA.CallByName更健壮而不是使用点语法来遍历解析的JSON对象。

在这个问题中，询问如何遍历解析的JSON数组。首先，这是一个miniscript方法戴着帽子小贴士向ozmike https://stackoverflow.com/users/334106/ozmike

'Tools->References->
'Microsoft Script Control 1.0;  {0E59F1D2-1FBE-11D0-8FF2-00A0D10038BC}; C:\Windows\SysWOW64\msscript.ocx

Private Sub TestJSONParsingArrayWithMiniScript()
    'Hat tip to ozmike  https://stackoverflow.com/users/334106/ozmike
    'Based on https://stackoverflow.com/questions/5773683/excel-vba-parsed-json-object-loop#19359035
    Dim oScriptEngine As ScriptControl
    Set oScriptEngine = New ScriptControl
    oScriptEngine.Language = "JScript"
    oScriptEngine.AddCode "Object.prototype.myitem=function( i ) { return this[i] } ; "

    Dim sJsonString As String
    sJsonString = "[ 1234, 2345 ]"

    Dim objJSON As Object
    Set objJSON = oScriptEngine.Eval("(" + sJsonString + ")")

    Debug.Assert objJSON.myitem(0) = 1234
    Debug.Assert objJSON.myitem(1) = 2345


End Sub

但不管你信不信，VBA.CallByName可以原生使用，不仅可以获得数组的长度，还可以访问元素。见答案。

这是5系列的问题2.这是完整的系列

Q1 In Excel VBA on Windows, how to mitigate issue of dot syntax traversal of parsed JSON broken by IDE's capitalisation behaviour?

Q2 In Excel VBA on Windows, how to loop through a JSON array parsed?

Q3 In Excel VBA on Windows, how to get stringified JSON respresentation instead of “[object Object]” for parsed JSON variables?

Q4 In Windows Excel VBA,how to get JSON keys to pre-empt “Run-time error '438': Object doesn't support this property or method”?

Q5 In Excel VBA on Windows, for parsed JSON variables what is this JScriptTypeInfo anyway?

Answer 1

所以VBA.CallByName也访问数组中的元素以及查找数组的长度

'Tools->References->
'Microsoft Script Control 1.0;  {0E59F1D2-1FBE-11D0-8FF2-00A0D10038BC}; C:\Windows\SysWOW64\msscript.ocx

Private Sub TestJSONParsingArrayWithCallByName()

    Dim oScriptEngine As ScriptControl
    Set oScriptEngine = New ScriptControl
    oScriptEngine.Language = "JScript"

    Dim sJsonString As String
    sJsonString = "[ 1234, 2345 ]"

    Dim objJSON As Object
    Set objJSON = oScriptEngine.Eval("(" + sJsonString + ")")

    '* Using VBA.CallByName we get the length of the array

    Dim lLength As Long
    lLength = VBA.CallByName(objJSON, "length", VbGet)

    Debug.Assert lLength = 2

    '* Believe or not one uses "0","1",.... with callbyname to get an element
    Debug.Assert VBA.CallByName(objJSON, "0", VbGet) = 1234
    Debug.Assert VBA.CallByName(objJSON, "1", VbGet) = 2345


End Sub

在Windows上的Excel VBA中，如何循环解析JSON数组？

1 个答案: