如何在Borland C ++ Builder上创建按钮数组并使用它？

问题描述

如何在Borland C ++ Builder上创建按钮数组并使用它？

How to create an array of buttons on Borland C++ Builder and work with it?

我正在使用Borland C ++ Builder 6和Borland Developer Studio 2006（Turbo C ++ 2006）。

I'm using Borland C++ Builder 6 and Borland Developer Studio 2006 (Turbo C++ 2006).

仅使用带有索引的for循环来处理表单上的许多按钮，例如，更改其标题，大小和位置。

To work with a lot of buttons on a form just using a for loop with an index, for example, changing their caption, size and position.

我知道是否如果我创建另一个按钮（通过 TButton * Button2 = new TButton（Form1），则有一个名为 Button1 的按钮，并且在此按钮的click事件内） code>），我可以将 Button1 分配给 Button2 （ Button2 = Button1 ），而我只需用 Button2->标题修改 Button1 的标题。因此，我想扩展它，将真实组件的指针分配给数组元素，并通过 for 循环将它们与所有组件一起使用。

I know if I have a button called Button1 and inside a click event of this button if I create another button (through TButton *Button2 = new TButton(Form1)), I can assign Button1 to Button2 (Button2 = Button1) and them I can simply modify caption of Button1 with Button2->Caption. So I would like to extend it assigning pointers of real components to elements of an array to them work with all of them with a for loop.

好吧，如果有人找到了一种将所有按钮添加为表单上的数组的方法，那就更好了：）

Well, if someone found an way to add all buttons as an array on a form, it's better :)

进行了以下测试，将相应的代码放在TForm1 :: Button1Click（）上，这是表单上按钮的事件：

Following tests were made putting respective code on TForm1::Button1Click(), an event of a button on a form:

• 测试1

• Test 1

• 说明：直接创建数组



• 代码：

• Description: Creating an array directly

• Code:

TButton Buttons[3];




结果：编译错误：

Result: Compile error:

> [C++ Error] Unit1.cpp(23): E2248 Cannot find default constructor
> to initialize array element of type 'TButton'

注释：

• 我测试了此测试的一些变体（例如， TButton Buttons = new TButton [3] ，与 calloc 和其他函数），但是所有这些都指出了 TButton 没有没有参数的构造函数的问题，即 TButton（），但只有 TButton（TComponent * AOwner）， TButton（void * ParentWindow）和 TButton（const TButton&）;


• 使用运算符 new 的任何方式 TButton 构造函数原型的参数，用于数组吗？


• Comments:
  • I tested some variants of this test (e.g. TButton Buttons = new TButton[3], working with calloc function and others), but all of them points to the issue that TButton does not have a constructor without arguments, i.e., TButton(), but only TButton (TComponent *AOwner), TButton(void *ParentWindow) and TButton(const TButton &);
  • Any way to use operator new with arguments for TButton constructor prototypes, for an array?

  测试2

  
  
  • 描述：创建向量
  
  

  • 代码：还要在单元标题上添加 #include vector.h ...

  vector<TButton> Buttons;
  Buttons[0].Caption="it is ok";
  Buttons[1].Caption="mayday, mayday";
  

  
  

  • 结果：第三行的调试器异常：

  • Result: Debugger exception on 3rd line:

    > Project Project1.exe raised exception class EAccessViolation
    > with message 'Acceess violation at address 401075B9 in module
    > 'vcl60.bpl'. Read of address 00000254'. Proccess stopped. Use
    > Step or Run to continue.
    

  
  
  • 评论：
    
    
    
    • 是的，我希望它会被提出，但是我在这里向某人说，创建后如何为该向量上的更多元素分配内存，因为 vector< TButton> Buttons（3）; 由于test1失败的相同原因而无法工作：（
    
    
    • Comments:
      • Yeah, I expected that it would be raised, but I put it here to someone say how to allocate memory for more elements on that vector after created, since vector<TButton> Buttons(3); does not work for the same reason test1 failed :(

      对于任何视觉组件，该如何做？

      How to do it for any visual component?

      推荐答案

      由于相同的原因，所有尝试均以失败告终-您正在尝试创建实际 TButton 对象实例，而不是 TButton 实例的指针的数组/向量。

      All of your attempts failed for the same reason - you are trying to create an array/vector of actual TButton object instances instead of an array/vector of pointers to TButton instances.

      要创建按钮的固定长度数组指针：

      To create a fixed-length array of button pointers:

      TButton* Buttons[3];
      ...
      Buttons[0] = Button1;
      Buttons[1] = Button2;
      Buttons[2] = Button3;
      ...
      for(index = 0; index < 3; ++index)
      {
          TButton *Btn = Buttons[index];
          // use Btn as needed...
      }
      

      创建按钮指针的动态长度数组：

      TButton** Buttons;
      ...
      Buttons = new TButton*[3];
      Buttons[0] = Button1;
      Buttons[1] = Button2;
      Buttons[2] = Button3;
      ...
      for(index = 0; index < 3; ++index)
      {
          TButton *Btn = Buttons[index];
          // use Btn as needed...
      }
      ...
      delete[] Buttons;
      

      创建按钮指针的向量：

      std::vector<TButton*> Buttons;
      ...
      Buttons.push_back(Button1);
      Buttons.push_back(Button2);
      Buttons.push_back(Button3);
      ...
      for(index = 0; index < 3; ++index)
      {
          TButton *Btn = Buttons[index];
          // use Btn as needed...
      }
      /*
      Or:
      for(std::vector<TButton*>::iterator iter = Buttons.begin(); iter != Buttons.end(); ++iter)
      {
          TButton *Btn = *iter;
          // use Btn as needed...
      }
      */
      

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