动态转换表单 [英] Cast a form dynamically

问题描述

我正在编写一个程序来关闭所有创建的adoquery并在(任何)表单上打开，问题是我需要对表单进行强制转换以标识组件.如何进行如示例所示的动态投射?

I am writing a procedure to close all adoquery created and open on a (any) form, the problem is I need to do a cast on the form to identify the components. how can I make a dynamic cast like shown in the example?

我需要这样的东西

Procedure OpenADODataSets(Form:TForm;FormType:TClass);
...
...
(Form as FormType).ComponentCount

或

Procedure OpenADODataSets(Form:TForm;FormType:TClass);
...
...
FormType(Form).ComponentCount

这是代码.

Procedure OpenADODataSets(Form:TForm;FormType:TClass);
var
  i: integer;
begin

    for i:=0 to (Form as FormType).ComponentCount-1 do
     if (Form as FormType).Components[i].ClassType=TADOQuery then
       if not TADOQuery((Form as FormType).Components[i]).Active then
        TADOQuery((Form as FormType).Components[i]).Open;

end;

更新

问题由@Edelcom的答案解决

problem solved with the answer of @Edelcom

Procedure OpenADODataSets(Form:TForm);
var
  i: integer;
begin

    for i:=0 to Form.ComponentCount-1 do
     if Form.Components[i].ClassType=TADOQuery then
       if not TADOQuery(Form.Components[i]).Active then
        TADOQuery(Form.Components[i]).Open;

end;

推荐答案

为什么需要(作为FormType的表单)(如我所评论).查找了一些我自己的代码，效果很好:

Why do you need the (Form as FormType) (as I commented). Looked up some of my own code, which works fine :

procedure TProgSettingsVisual.FillStandardSaveFilesForForm( const pForm: TForm;);
var i : integer;
    x : string;
    thisComponent : TComponent;
begin
   With pForm do
   begin
      for i := 0 to ComponentCount-1 do
      begin
         thisComponent := Components[i];

         x := LowerCase(Components[i].ClassName);


         if x = 'tovcinifilestore'
         then begin
            TOvcIniFileStore(Components[i]).IniFileName := FormSaveFile(pForm);
         end;

         if x = 'tovdformstate'
         then begin
             ...
         end;

         if x = 'tovccomponentstate'
         then begin
              ...

这篇关于动态转换表单的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！