我想知道我使用“退格”的时间有多少在VB.NET上 [英] I want to know how many time I using "backspace" on VB.NET

问题描述

在这个richtextbox中，我想知道在键盘上使用Backspace的次数。到目前为止我已经使用了这段代码，但是出了点问题。这是场景，当按Enter键时，消息框将显示使用Backspace的时间。请帮帮我..



我尝试过：

In this richtextbox I want to know how many time using "Backspace" on keyboard. So far I already using this code, but something wrong. this is the scenario, When pressing Enter, message box will show how many time using Backspace. Please help me..

What I have tried:

Public Class Form1
    Private Sub RichTextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles RichTextBox1.KeyDown
        Dim count As Integer

        If (e.KeyCode = Keys.Back) Then
            count = count + 1
        ElseIf (e.KeyCode = Keys.Enter) Then
            MessageBox.Show(count)
        End If

    End Sub
End Class

推荐答案

count 是一个局部变量，它只在方法退出时存在，并在每次新事件调用该方法时重新创建并重新初始化。



你需要通过在方法之外移动它来使它成为你的班级声明的艺术：

count is a local variable, it exists only until the method exits and is recreated and reinitialised each time the method is called by a new event.

You need to make it art of your class declaration by moving it outside the method:

Public Class Form1
    Private count As Integer = 0

    Private Sub RichTextBox1_KeyDown(ByVal sender As Object, ByVal e As KeyEventArgs)
        If (e.KeyCode = Keys.Back) Then
            count = count + 1
        ElseIf (e.KeyCode = Keys.Enter) Then
            MessageBox.Show(count)
        End If
    End Sub
End Class

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