如何在另一个事件中创建一个keydown事件？

本文介绍了如何在另一个事件中创建一个keydown事件？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我希望能够退出我创建的新表单，但是由于我手动创建表单，因此在withevents中没有处理程序。所以，既然我无法弄清楚我的生活是如何接近我的形式，我提出了另一种可能的解决方案。 我认为我可以在填充新表单的事件中创建一个keydown事件。现在它不起作用，但我希望问一个人我是否在正确的轨道上，可能他们知道我需要改变什么？ 这是我的代码：

Dim dk As System.Windows.Forms.KeyEventArgs dk = sender if dk.KeyCode = Keys.Escape然后 picform.Close（）结束如果

我尝试了什么： 我尝试将dk值更改为整数并尝试将其更改为键值，没有人帮助过。

解决方案

将代码重构（提取）为新方法（Sub / Function）。然后，您可以从代码中的多个位置调用它。例如： 之前：

公开 类 Form1 私有 Sub Form1_KeyDown（发件人作为 对象，e As KeyEventArgs）句柄 MyBase .KeyDown ' 代码在这里做了一些事情！ 结束 Sub 结束 Class

AFTER：

公开 类 Form1 私人 Sub Form1_KeyDown（sender As Object ，e As KeyEventArgs）句柄 MyBase .KeyDown NewMethod（） 结束 Sub Sub NewMethod（） ' 代码在这里做了一些事情！ 结束 Sub Sub OtherMethod（） NewMethod（） 结束 Sub 结束 类

更新了新要求：对于新要求，您需要使用 WithEvents 来捕获KeyDown事件。这是一个反映这一点的新示例。 公共 类 Form1 私有 Sub Button1_Click（发件人 As 对象，e As EventArgs）句柄 Button1.Click OpenForm（） 结束 Sub 私人 WithEvents picform 作为 新表格 Sub OpenForm（） picform.Height = 800 p icform.Width = 600 ' picform。 FormBorderStyle = FormBorderStyle.None picform.Show（） 结束 Sub 私有 Sub picform_KeyDown（sender 作为 对象，e As KeyEventArgs）句柄 picform.KeyDown MsgBox（ Picformn以父表单，MsgBoxStyle.Exclamation获取的keydown事件 结束 Sub 结束 类

非常感谢到Graeme_Grants解决方案我能够弄清楚其余部分，我只需要一种方法来获得这个处理器。

Private WithEvents picform As New表格 Dim picform As New Form picform.Controls.Add（expandpic） picform.Height = 800 picform.Width = 600 'picform .FormBorderStyle = FormBorderStyle.None picform.Show（） AddHandler picform.KeyDown，AddressOf picform_convert End Sub Private Sub picform_convert（ByVal sender As System.Object，ByVal e As KeyEventArgs） picform = CType（sender，Form） 如果e.KeyCode = Keys.Escape那么 picform.Close（） picform.Dispose（） End if End Sub

只是想出了其余的，谢谢你的帮助。现在我知道如何调用一个withevent处理程序以供将来参考。

I want to be able to exit a new form I created, but since I manually made the form its does not have a handler in the withevents. So since I can not figure out for the life of me how to approach getting my form into the withevents, I came up with another possible solution. I figured that I could make a keydown event inside the event that populates the new form. Right now it's not working, but I was hoping to ask someone if I am on the right track, and possibly if they know what I need to change? Here is my code:

Dim dk As System.Windows.Forms.KeyEventArgs dk = sender If dk.KeyCode = Keys.Escape Then picform.Close() End If

What I have tried: I have tried changing the dk value into an integer and also tried changing it to a key value, none have helped.

解决方案

Refactor (extract) the code into a new method (Sub/Function). Then you can call it from multiple places in your code. Example: BEFORE:

Public Class Form1 Private Sub Form1_KeyDown(sender As Object, e As KeyEventArgs) Handles MyBase.KeyDown ' code does something here! End Sub End Class

AFTER:

Public Class Form1 Private Sub Form1_KeyDown(sender As Object, e As KeyEventArgs) Handles MyBase.KeyDown NewMethod() End Sub Sub NewMethod() ' code does something here! End Sub Sub OtherMethod() NewMethod() End Sub End Class

Updated with new requirement: For the new requirement, you need to use WithEvents to capture the KeyDown event.Here is a new example to reflect this.

Public Class Form1 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click OpenForm() End Sub Private WithEvents picform As New Form Sub OpenForm() picform.Height = 800 picform.Width = 600 ' picform.FormBorderStyle = FormBorderStyle.None picform.Show() End Sub Private Sub picform_KeyDown(sender As Object, e As KeyEventArgs) Handles picform.KeyDown MsgBox("Picformn keydown event caputred in parent form", MsgBoxStyle.Exclamation) End Sub End Class

So thanks to Graeme_Grants solution I was able to figure out the rest, I just needed a way to get the withevent handler.

Private WithEvents picform As New Form Dim picform As New Form picform.Controls.Add(expandpic) picform.Height = 800 picform.Width = 600 ' picform.FormBorderStyle = FormBorderStyle.None picform.Show() AddHandler picform.KeyDown, AddressOf picform_convert End Sub Private Sub picform_convert(ByVal sender As System.Object, ByVal e As KeyEventArgs) picform = CType(sender, Form) If e.KeyCode = Keys.Escape Then picform.Close() picform.Dispose() End If End Sub

Just figured out the rest, thanks for the help. now I know how to call forth an withevent handler for future reference.