如何从表单单元外部访问delphi控件？ [英] How can I access a delphi control from outside the form's unit?

问题描述

我试图从这样定义的过程中调用Timer的Enabled属性： procedure Slide（Form：TForm; Show：Boolean）; 而不是固定的表单名称（例如： Form2.Timer ... ）

I'm trying to call the Enabled property of a Timer from a procedure defined like this: procedure Slide(Form: TForm; Show: Boolean); and not with a fixed form name (like: Form2.Timer...)

将表单的单位放入使用后列表，这行得通： Form2.Timer1.Enabled：= True;
但以下项不起作用： Form.Timer1.Enabled： = True; （其中Form是作为参数传递给过程的表单。

After putting the form's unit in the uses list, this works: Form2.Timer1.Enabled := True; but the following is not working: Form.Timer1.Enabled := True; (where Form is the form passed as parameter to the procedure.

如何访问表单上的Timer组件？

How to get access to the Timer component on my form?

预先感谢。

推荐答案

您不能从以下位置访问计时器您的过程，因为您的参数是TForm，并且TForm没有Timer1成员。您必须像这样调整过程：

You cannot access the Timer from your procedure because your parameter is a TForm, and TForm does not have a Timer1 member. You have to adjust your procedure like this:

uses
  Unit2; //unit with your form

procedure Slide(Form: TForm2; Show: Boolean); //change TForm2 to the classname you use
begin
  Form.Timer1.Enabled := True;
end;

编辑：

如果要传递任何形式，可以尝试以下操作：

If you want to pass any form, you can try this:

procedure Slide(Form: TForm; const aTimerName: string; Show: Boolean);
var
  lComponent: TComponent;
begin
  lComponent := Form.FindComponent(aTimerName);
  if Assigned(lComponent) and (lComponent is TTimer) then
    TTimer(lComponent).Enabled := True;
end;

通过表单上的按钮调用：

Call like this from a button on your form:

procedure TForm2.Button1Click(Sender: TObject);
begin
  Slide(Self, 'Timer1', False);
end;

或者您可以让Form继承一个带有打开计时器方法的接口。不过，这有点复杂。

Or you let your Form inherit an interface with methods to turn on the timer. It's a little bit more complicated though.

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