C＃ - 使用eventListener将父窗体上的ListBox.Items设置为子窗体？ [英] C# - Set ListBox.Items on Parent Form to Child Form using an eventListener maybe?

问题描述

我会尝试轻松快速地解释，

我有一个主表格（form1）自动加载儿童表格（form2）（所以我有两种形式打开）。



在主窗体中我做了一些数学等事情，当只有algorythm完成工作时，我需要将一些值返回到ListBox在form2上。



我一直在网上寻找4-5小时的解决方案，没有一个能满足我的需求。



由于form2在数学作业完成之前打开，因此我无法在打开它时设置这些值。所以我想我需要使用一些EventHandler。



有关如何实现的想法吗？



我为你添加一些空白代码，以帮助我在视觉上更轻松地使用



FORM1（MAIN ONE / Parent）

Hi,
i'll try to explain easily and quickly,
I have a Main Form (form1) loading automatically a Child Form (form2) (so i have two forms opened).

In Main Form i do some math things etc and WHEN only the algorythm is done working, i would need to return some values into a ListBox that is on form2.

I have been looking for solution over the web for like 4-5 hours, none were fitting my needs.

Since form2 is opened before the math job is done, i cant set the values while opening it. SO i guess i need to use some EventHandler.

Any idea on how to implement that please?

im adding some blank code for you to help me visually easier maybe

FORM1 (MAIN ONE/Parent)

private string doMath() {
     //blabla
     return "formated:string:to:use:for:List";
}

displayList(doMath());  //HERE IS THE HOW? cant access function on form2

FORM2（儿童）

FORM2 (Child)

private void displayList(string listItems) { //
     string[] delim = { ":" };
     string[] returndata = listItems.Split(delim, StringSplitOptions.RemoveEmptyEntries);
     listBox1.Items.Clear();
     for (var i = 0; i < listItems.Length; i++)
     {
        this.listBox1.Items.Add(listItems[i]);
     }
     if (this.listBox1.Items.Count > 0)
     {
         this.listBox1.SelectedIndex = 0;
     }
}

先谢谢你们。

thanks in advance guys.

推荐答案

使form2成为一个类变量。向form2添加一个方法来更新/添加文本到列表框。

当表单1进程完成时调用该方法

make form2 a class variable. add a method to form2 to update/add text to listbox.
when form 1 process is finished call that method

我认为你的表单不是真的孩子和父母。如果没有将 Forms.TopLevel 设置为false（不要这样做！），在尝试设置任何表单的 Parent 。



看起来这是一个关于表单协作的热门问题。最强大的解决方案是在表单类中实现适当的接口，并传递接口引用而不是引用Form的整个实例。有关更多详细信息，请参阅我以前的解决方案：如何以两种形式复制列表框之间的所有项目 [ ^ ]。



另请参阅此处的其他解决方案讨论。如果应用程序足够简单，解决方案就像在一个表单中声明一些 internal 属性并将对一个表单的实例的引用传递给另一个表单的实例一样简单形成。对于更复杂的项目，这种违反严格封装的样式和松散耦合可能会增加代码的意外复杂性并引发错误，因此封装良好的解决方案将是优惠。



另请参阅：

http://en.wikipedia.org/wiki/Accidental_complexity [ ^ ]，

http://en.wikipedia.org/wiki/Loose_coupling [ ^ ]。

-SA

I don't think your forms are really child and parent. Without setting Forms.TopLevel to false (don't do it!), you would get an exception at attempt to set any form's Parent.

It looks like a popular question about form collaboration. The most robust solution is implementation of an appropriate interface in form class and passing the interface reference instead of reference to a "whole instance" of a Form. Please see my past solution for more detail: How to copy all the items between listboxes in two forms[^].

Please also see other solutions in this discussion. If the application is simple enough, the solution could be as simple as declaring of some internal property in one form and passing a reference to the instance of one form to the instance of another form. For more complex projects, such violation of strictly encapsulated style and loose coupling could add up the the accidental complexity of the code and invite mistakes, so the well-encapsulated solution would be preferable.

Please see also:
http://en.wikipedia.org/wiki/Accidental_complexity[^],
http://en.wikipedia.org/wiki/Loose_coupling[^].

—SA

由于这个问题非常受欢迎，我以前的答案往往不太清楚，可能还不清楚够了，我决定写一篇完整的提示/技巧文章，详细的代码示例和解释：一次回答的许多问题 - Windows窗体或WPF Windows之间的协作。

-SA

As the question turned out to be very popular, and my previous answers often were not well understood, probably were not clear enough, I decided to write a Tips/Trick article complete with detailed code samples and explanations: Many Questions Answered at Once — Collaboration between Windows Forms or WPF Windows.

—SA

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