Question

我已经宣布了这些新类型：

type
 TRacer = record
  name: string;
  win, tie, loss, points: integer;
 end;

 TRacersList = TList<TRacer>;

我在数据模块中有一个程序如下：

procedure DMConnection.getDivision(aList: TRacersList; const game, id: string);
begin

 //1) setup the REST params
 RESTRequest.Params[0].Value := game;
 RESTRequest.Params[1].Value := id;

 //2) execute async so UI won't freeze
 RESTRequest.ExecuteAsync(procedure
 var tmp: TRacer;
    ja: TJSONArray;
    jv: TJSONValue;
 begin

  //parse the JSON. The RESTResponse is a TRESTResponse that holds the result of the RESTRequest. I have made a test inside the component (right click -> execute) and it works properly (= I can see the JSON inside the Content property).
  ja := TJSONObject.ParseJSONValue(RESTResponse.Content) as TJSONArray;

  for jv in ja do begin
   tmp.name := jv.GetValue<string>('name');
   tmp.win := jv.GetValue<integer>('Wins');
   tmp.tie := jv.GetValue<integer>('Ties');
   tmp.loss := jv.GetValue<integer>('Loss');
   tmp.points := jv.GetValue<integer>('Pts');

   aList.Add(tmp);
  end;

 end);

end;

如果您想知道，这是JSON字符串：

[{"name":"payer1","Wins":"1","Ties":"0","Loss":"0","Pts":"3"},{"name":"Velocity","Wins":"0","Ties":"0","Loss":"1","Pts":"0"},{"name":"test2","Wins":"0","Ties":"0","Loss":"0","Pts":"0"}]

在主窗体中，我能够以这种方式调用该过程：

DMConnection.getDivision(myList, 'mku', 'k2');

我有以下问题。变量myList: TRacersList在表单的OnCreate和OnDestroy事件中创建并释放。如果您尝试运行此代码：

DMConnection.getDivision(myList, 'mku', 'k2');
ShowMessage(myList.Count.toString);

结果为0.相反，如果我将aList.Add(tmp); OUTSIDE 设置为异步请求（例如，在参数设置之前），则计数为1.

这意味着当列表位于ExecuteAsync的完成处理程序之外时，该列表正在填充，但是当列表位于其中时，它不会被填充。有什么想法吗？

我已经知道，默认情况下，Synchronize设置为True，因此添加

TTHread.Synchronize(nil, procedure
begin
 aList.Add(tmp);
end)

没用。我该怎么办？我希望在数据模块中有这个解析/休息的东西，这样我就可以将互联网内容与我的app实现分开。

Delphi REST请求异步无法填充TList

0 个答案: