为什么 GotFocus 事件不断从 Designer 中删除自身? [英] Why does GotFocus event keep deleting itself from Designer?

问题描述

我想将 GotFocus 事件添加到 Windows 窗体文本框，因此我使用了 这个问题；它有效，但在我运行我的应用程序几次后，这段代码会自行删除，我不知道为什么.

I wanted to add a GotFocus event to a Windows Forms Textbox, so I used the method described in this question; it works, but after I run my application a couple of times the piece of code deletes itself and I don't know why.

这是不断删除自己的代码:

This is the code that keeps deleting itself:

txtID.GotFocus += txtID_GotFocus;

推荐答案

它会消失，因为您在添加事件处理程序时没有使用 WinForms 设计器使用的约定.

It disappears because you don't use conventions that are used by WinForms designer when you add event handlers.

使用 GotFocus 或 Enter 事件都没有关系.如果您(在 Designer.cs 中)以这种方式手动添加事件处理程序:

It doesn't matter whether you use GotFocus or Enter event. If you (in your Designer.cs) manually add event handler this way:

txtID.Enter += txtID_Enter;

那么下次您在设计器界面上移动控件时，它总是会从设计器中消失.

then it would always disappear from designer next time you move control on designer surface.

您必须以这种方式添加事件处理程序:

txtID.GotFocus += new System.EventHandler(txtID_Focus);
txtID.Enter += new System.EventHandler(txtID_Enter);

并且没有任何东西会消失，因为这是设计师期望代码的方式.

and nothing would disappear because it's the way designer expects code to be.

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