Question

我在设法找到方法时遇到了麻烦。

我希望我的应用程序在按下小键盘上的某个键时为用户显示一个消息框。主要问题是它必须以焦点形式完成。使用VB.NET无法找到任何方法

Answer 1

声明：

Private Declare Function GetAsyncKeyState Lib "user32" (ByVal vKey As Integer) As Integer
Dim result As Integer

formload：

Timer1.interval = 1
timer1.start()

Timer1.tick：

For i = 1 To 255 
result = 0 
result = GetAsyncKeyState (i)
If result = -32767 Then 
            If i = 103 Then
                MsgBox("Num 7")
            End If
End If 
Next i

：）

Answer 2

您实际谈论的内容称为Global KeyboardHook，因为您想要收听不是针对您的程序的消息。 CodePlex（Application and Global Mouse and Keyboard Hooks Library）上有一个很好的库，可以为.Net实现这个。

这是一个非常简单的示例，您需要下载上面的库并将MouseKeyboardActivityMonitor添加到您的参考文献中。

Imports MouseKeyboardActivityMonitor
Imports MouseKeyboardActivityMonitor.WinApi

Public Class Form1
    Private WithEvents myKeyboardHookManager As KeyboardHookListener
    Dim hookEnabled As Boolean
    Public Sub New()

        InitializeComponent()

        myKeyboardHookManager = New KeyboardHookListener(New GlobalHooker())
        myKeyboardHookManager.Enabled = True
    End Sub

    Private Sub HookManager_KeyDown(sender As Object, e As KeyEventArgs)
        Select Case e.KeyCode
            Case Keys.NumPad0 To Keys.NumPad9
                MessageBox.Show("KeyCode = " & e.KeyCode & vbCrLf & "Number = " & (e.KeyCode - 96))

        End Select


    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If hookEnabled Then
            hookEnabled = False
            RemoveHandler myKeyboardHookManager.KeyDown, AddressOf HookManager_KeyDown
        Else
            hookEnabled = True
            AddHandler myKeyboardHookManager.KeyDown, AddressOf HookManager_KeyDown
        End If
    End Sub
End Class

检测到按下某个Numpad键时，Form不在焦点上

2 个答案: