如何在基本表单中获取继承表单的大小？ [英] How to get the size of an inherited form in the base form?

问题描述

假设您有一个名为 FormBase 的表单，所有其他表单都从该表单继承。

例如，我有公共类Form formTest：FormBase

Suppose you have a form called FormBase and all other forms inherit from this form.
For example, I have public class Form formTest : FormBase

我现在在formTest的目录中拥有的内容：

What I have now in the ctor of formTest:

public class Form formTest : FormBase
{
    public formTest()
    {
        InitializeComponent();
        Program.MainForm.AddToFormSizes(this, this.Size);
    }
}

此代码添加 formTest 到主表单上具有 size

This code adds the instance of formTest to a dictionary on the mainform with its size

的词典我想将这段代码移到 FormBase ，这样我就不必在每一个继承的表单中都放这行代码。

This works, but I would like to move this code to FormBase so I don't have to put this line of code in every inherited form.

public class Form FormBase : Form
{
    public FormBase()
    {
        InitializeComponent();
        Program.MainForm.AddToFormSizes(this, this.Size);
    }
}

现在，问题是当我这样做时， size 在设计时的大小为 FormBase ，而不是 formTest 。

Now, the problem is that when I do that, size will have the size of FormBase in design-time, not the size of formTest.

FormBase 中是否可以捕获 formTest 或从 FormBase 继承的任何其他形式？

Is there a way in FormBase to capture the size of formTest or any other form that inherited from FormBase?

供参考，这是 AddToFormSizes 在MainForm中

for reference, this is the code of AddToFormSizes in the MainForm

private Dictionary<Form, Size> _formSizes = new Dictionary<Form, Size>();
public void AddToFormSizes(Form form, Size size)
{
    _formSizes.Add(form, form.Size);
}

推荐答案

问题：

使用 Form 作为其他Form的基础，在基类构造函数中， this 引用返回基类的 Size 而不是 Size 的派生类。

Problem:
Using a Form as base for other Forms, in the base class constructor, the this reference returns the Size of the base class instead of the Size of the derived class.

public class FormBase : Form
{
    public FormBase()
    {
        InitializeComponent();
        Program.MainForm.AddToFormSizes(this, this.Size);
    }
}

只需遵循以下事件顺序即可：

It's just a matter of following the sequence of events:

FormDerived derived = new FormDerived()
=> FormBase.InitializeComponent()
=> FormDerived.InitializeComponent()
derived.Show()
=> FormBase.OnHandleCreated()

---

给出a的构造函数从 FormBase 派生的表单：

---

Given the constructor of a Form derived from FormBase:

public class FormDerived : FormBase
{
     public FormDerived() => InitializeComponents();    
}

首次创建该类时：

FormDerived derived = new FormDerived();
derived.Show();

基类的构造函数（ FormBase ）首先被称为。

此时， 此 引用被设置为 FormDerived ，但所有属性，包括 Name 和表单的标题（ Text ），设置为基类的值。

因此，调用使用 this 的方法>在基类构造函数中：

the constructor of the base class (FormBase) is called first.
At this point, the this reference is set to FormDerived, but all the properties, including the Name and the Form's Caption (Text), are set to the values of the base class.
Hence, calling a method that uses this in the base class constructor:

Program.MainForm.AddToFormSizes(this, this.Size);

this.Size 将返回基类，而不是派生类。

this.Size will return the Size of the base class, not the derived class.

接下来调用 FormDerived 构造函数。此时，将设置 InitializeComponent（）方法中定义的所有属性。

The FormDerived constructor is called next. At this point, all the properties defined in the InitializeComponent() method will be set.

如果将 AddToFormSizes（）方法移动到派生类构造函数，则 this 将参考期望值。但是，必须在 FormBase 的每个派生类中插入静态方法调用。

If the AddToFormSizes() method is moved to the derived class constructor, this will reference the expected values. But, the static method call must be inserted in each derived class of FormBase.

AddToFormSizes（）方法可以移至覆盖的 <$ c $基类的c> OnHandleCreated（） 方法，该方法将在首次显示派生的Form时调用：

The AddToFormSizes() method can be instead moved to and called from the overridden OnHandleCreated() method of the base class, which will be called when the derived Form is first shown:

derived.Show();

将导致调用 FormBase.OnHandleCreated（） 。

will cause a call to FormBase.OnHandleCreated().

此时， this 引用已设置为派生类，并且在 InitializeComponent（）中定义的所有属性都已经设置为派生类的值。

名称，文本和大小。

At this point, the this reference is already set to the derived class and all the properties defined in InitializeComponent() will be already set to the values of the derived class.
Name, Text and Size included, of course.

此处， 此 是 FormDerived ，并在其构造函数中设置了所有属性：

Here, this is FormDerived with all the properties set in its constructor:

public class FormBase : Form
{
    public FormBase() => InitializeComponent();

    protected override void OnHandleCreated(EventArgs e)
    {
         base.OnHandleCreated(e);
         Program.MainForm.AddToFormSizes(this, this.Size);
    }
}

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