使用VBA和JSON解析嵌套數組

Question

我有一個JSON我想在VBA中解析。我已經成功解析了「offer」的數組。在「offer」陣列內部是另一個陣列「價格」「USD」。

問題是並非每個「offer」對象都有「USD」數組。我試圖創建一個對象，我可以創建一個表格/工作表，但我甚至無法使用調試模式打印對象。這種方法有效，但因爲不是每個Dict OfferDetails都包含「USD」對象。

我想要做的是能夠打印字符串，如果「USD」對象丟失，只需跳過它並只打印具有「USD」的對象。我嘗試了IsMissing（在代碼中），但它在碰到缺少的「USD」對象時失敗。

任何想法如何我可以得到這個字符串與「USD」值？請注意，「USD」是一個數組幷包含多個對象，但我不知道如何解決它們。理想情況下，我想以「提供」的方式解析「美元」。我完全失去了，因爲我在VBA中不是很好

這是一個有效的Web JSON的工作腳本。

Sub getJSONEP_lib_working() 
     'Need the JsonConverter found here https://github.com/VBA-tools/VBA-JSON 
     'Need the Microsoft Scripting Runtime 

     Dim Parsed As Dictionary 
     Dim Item As Dictionary 
     Dim OfferDetails As Dictionary 
     Dim Price As Dictionary 
     Dim USD As Dictionary 

       URL = "http://wraymac.com/JSON/example1.json" 
       url2 = "[{" & """mpn""" & ":" & """41202""" & "}]" 

       Set MyRequest = CreateObject("WinHttp.WinHttpRequest.5.1") 
       MyRequest.Open "GET", URL 
       MyRequest.Send 

       JsonString = MyRequest.ResponseText 

       Dim json As Object 
       Set json = JsonConverter.ParseJson(JsonString) 


     Set Parsed = JsonConverter.ParseJson(MyRequest.ResponseText) 

     For Each Item In Parsed("results")(1)("items") 
      For Each OfferDetails In Item("offers") 


     'I tried this it doesn't work, it fails when it finds a non existent "USD" 
      If Not IsMissing(OfferDetails("prices")("USD")(1)(1)) Then 
      Debug.Print OfferDetails("prices")("USD")(1)(1) 
      Else 
      Debug.Print "Missing" 
      End If 


     x = Item("mpn") & " " & "sku" & " - " & OfferDetails("sku") & "," & "UID" & " - " & OfferDetails("seller")("uid") & " " & OfferDetails("moq") & "packaging" & " = " & OfferDetails("packaging") & " " & OfferDetails("seller")("name") & " " & Item("manufacturer")("name") 
     Debug.Print x 

     'This works but fails because not every Dict OfferDetails contains the "USD" object 
     'x = Item("mpn") & " " & "sku" & " - " & OfferDetails("sku") & "," & "UID" & " - " & OfferDetails("seller")("uid") & " " & OfferDetails("moq") & "packaging" & " = " & OfferDetails("packaging") & " " & OfferDetails("seller")("name") & " " & Item("manufacturer")("name")& " "&OfferDetails("prices")("USD")(1)(1) 

     Next OfferDetails 
      Next 

     End Sub 

Answer 1

您要使用的詞典的Exists方法：

Set Parsed = JsonConverter.ParseJson(MyRequest.ResponseText) 

For Each Item In Parsed("results")(1)("items") 
    For Each OfferDetails In Item("offers") 

      If OfferDetails("prices").Exists("USD") Then 
       Debug.Print OfferDetails("prices")("USD").Count & " items:" 
       Debug.Print "-----------------" 
       For Each x In OfferDetails("prices")("USD") 
        Debug.Print x(1), x(2) 
       Next x 
       Debug.Print "-----------------" 
      Else 
       Debug.Print "No USD" 
      End If 

    Next OfferDetails 
Next 

轉換器解析的對象（{}）將字典和數組（[]）收藏，所以你可以使用Count確定每種類型對象中的項目數量。