在Windows上的Excel VBA中,对于已解析的JSON变量,这个JScriptTyp

我机器上这种类型的完整细节是

Libary Name:    Microsoft Script Control 1.0 (Ver 1.0)       
LIBID:          {0E59F1D2-1FBE-11D0-8FF2-00A0D10038BC}
Location:       C:wINDOWSSysWOW64msscript.ocx

使用VBA IDE的对象浏览器和反汇编类型库的OLEVIEW.exe,我无法跟踪接口JScriptTypeInfo或方法hasOwnProperty.

但是脚本引擎不是主持语言实现的情况,例如VBScript和JScript(Javascript的Microsoft名称).
所以也许我们应该寻找一个JScript实现DLL,实际上这里有一个细节

Libary Name:    Microsoft JScript Globals
LIBID:          {3EEF9759-35FC-11D1-8CE4-00C04FC2B085}
Location:       C:wINDOWSSysWOW64jscript.dll

我的机器上没有注册,因此不在我的工具 – >参考库列表或OLEVIEW.exe中.我很幸运,一边寻找一边.
这是OLEVIEW的一些输出,给出了类型库的异常

[
  uuid(3EEF9758-35FC-11D1-8CE4-00C04FC2B097)
]
dispinterface ObjectInstance {
    properties:
    methods:
        [id(0x0000044c)]
        StringInstance* toString();
        [id(0x0000044d)]
        StringInstance* toLocaleString();
        [id(0x0000044e)]
        VARIANT hasOwnProperty(VARIANT propertyName);
        [id(0x0000044f)]
        VARIANT propertyIsEnumerable(VARIANT propertyName);
        [id(0x00000450)]
        VARIANT isPrototypeOf(VARIANT obj);
        [id(0x00000451)]
        ObjectInstance* valueOf();
};

上面显示hasOwnProperty是一个IDispatch接口(或dispinterface)的方法,用于处理声明为Object类型的VBA对象(例如Dim foo as Object)
使用regsvr32注册类型库似乎什么都不做.必须浏览到工具引用中的文件才能在VBA的对象浏览器中查看.

我们可以非常确定这个JScript.dll文件,因为使用Process Explorer我们可以看到在执行行时加载的dllEngine.Language =“JScript”
在缺少已注册的类型库的情况下,我将文件JScript.dll加载到记事本中,并将.J.S.c.r.i.p.t.T.y.p.e.I.n.f.o作为正则表达式进行搜索,并找到了匹配项.答对了！

不仅有一个ObjectInstance可以描述VBA程序遇到的大多数变量,而且还有一个有趣的ArrayInstance,也许我们可以使用Javascript自己的数组函数
或者至少是JScript.dll类型库中记录的子集.这是一些示例代码

'Tools->References->
'Microsoft Script Control 1.0;  {0E59F1D2-1FBE-11D0-8FF2-00A0D10038BC}; C:WindowsSysWOW64msscript.ocx

'and FYI/browsing capabilities       Microsoft JScript Globals;   C:wINDOWSSysWOW64jscript.dll

Option Explicit

Private Sub TestJSONParsingWithCallByName5()

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

    Dim sJsonString(0 To 1) As String
    sJsonString(0) = "{'key1': 'value1','key2': { 'key3': 'value3' } }"
    sJsonString(1) = "[ 1234,2345,3456,4567,5678,6789 ]"



    Dim objJSON(0 To 1) As Object
    Set objJSON(0) = oScriptEngine.Eval("(" + sJsonString(0) + ")")
    Set objJSON(1) = oScriptEngine.Eval("(" + sJsonString(1) + ")")

    Debug.Assert objJSON(0).hasOwnProperty("key1")
    Debug.Assert objJSON(0).hasOwnProperty("key2")

    Debug.Assert CallByName(objJSON(1),"length",VbGet) = 6
    Debug.Assert CallByName(objJSON(1),"0",VbGet) = "1234"

    '* Is objJSON(1) an ArrayInstance?
    '* does it support the reverse method of the ArrayInstance object?

    'Call objJSON(1).Reverse  '* reverse gets capitalised into Reverse ... grrrr
    Call CallByName(objJSON(1),"reverse",VbMethod) '* so use CallByName as solution to "helpful" capitalisation

    '* Yes,the elements are reversed!

    Debug.Assert CallByName(objJSON(1),VbGet) = "6789"

    Stop

    '** And now we know objJSON(1) is an ArrayInstance we can have some fun with array operations

    Dim objSplice As Object
    Set objSplice = CallByName(objJSON(1),"splice",VbMethod,2,1)
    Debug.Assert CallByName(objJSON(1),VbGet) = 5
    Debug.Assert CallByName(objSplice,VbGet) = 1

    Dim objSlice As Object
    Set objSlice = CallByName(objJSON(1),"slice",2)
    Debug.Assert CallByName(objJSON(1),VbGet) = 5
    Debug.Assert CallByName(objSlice,VbGet) = 3

    Stop
    Call CallByName(objJSON(1),"sort",VbMethod)


    Debug.Assert CallByName(objJSON(1),"join",VbMethod) = "1234,6789"
    Debug.Assert CallByName(objJSON(1)," ") = "1234 2345 3456 5678 6789"
    Stop


    Debug.Assert CallByName(objJSON(1),"pop",VbMethod) = "6789"
    Debug.Assert CallByName(objJSON(1),VbGet) = 4
    Stop
End Sub

概要：JScriptTypeInfo是在VBA IDE监视窗口中显示的东西,以及VBA函数TypeName()的返回,但它实际上隐藏了可以在JScript.dll中找到的许多对象.我认为它可以被描述为多态,也许更好地将其描述为后期绑定.要查看功能,请使用Tools-References并浏览到JScript.dll.