小编Jan*_*ich的帖子

I'm creating a VCL Application with Delpi 10.3 and want to support some web functionality by having the user enter the ISBN of a book into a TEdit component and from there passing/sending this value to a search field on this website: https://isbnsearch.org after which the website looks up the ISBN and displays the Author of the book. I want to somehow access the information (i.e Author) presented by the search result and again use it in my application.

This …

我正在 Delphi 中访问 TJSONValue（使用 REST 组件和 Google Books 的 API）。我想知道数组中有多少元素：'items'。这是 JSONValue 的格式：

   "kind": "books#volumes",
   "totalItems": 221,
   "items": [
       {...},
       {...},
       {...}]

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注意*“totalItems”不是指数组的大小。

我已经沿着这条线尝试了一些东西，但它引发了一个转换错误。

var
   JSONBook: TJSONValue;
   CountItems: integer;
begin
   JSONBook := RESTResponse1.JSONValue;

   ShowMessage(IntToStr(JSONBook.GetValue<string>('items').Length));
   CountItems := JSONBook.GetValue<string>('items').Length;

   for i := 0 to CountItems-1 do
   begin
     ...
   end;
end;