How to simulate mouse click? - vb.net

Question

I'm trying to make a program to click with keyboard like in Osu!.
I've tried SendKeys(), RaiseMouseEvent() and OnMouseClick(). Now I'm trying this and can't get anything to work.
The error I keep getting is:
PInvoke restriction: cannot return variants.
Public Class Form1
Dim onn As Boolean = False
Declare Function mc Lib "user32.dll" Alias "mouse_event" (flag, x, y, button, extra)
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If Not onn Then
Button1.Text = "Off"
Label1.Text = "Status: On"
onn = True
ElseIf onn Then
Button1.Text = "On"
Label1.Text = "Status: Off"
onn = False
End If
End Sub
Private Sub Form1_KeyPress1(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles Me.KeyPress
If onn And (e.KeyChar = "Z" Or e.KeyChar = "X" Or e.KeyChar = "z" Or e.KeyChar = "x") Then
mc(&H2, 0, 0, 0, 0)
mc(&H4, 0, 0, 0, 0)
End If
End Sub
End Class

Answer 1

This examples clicks where the mouse currently is when the feature is in the "onn" state:
Public Class Form1
Private onn As Boolean = False
Private Declare Sub mouse_event Lib "user32" (ByVal dwFlags As Integer, _
ByVal dx As Integer, ByVal dy As Integer, ByVal cButtons As Integer, _
ByVal dwExtraInfo As Integer)
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Me.KeyPreview = True
Button1.Text = "Off"
End Sub
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
onn = Not onn
Button1.Text = IIf(onn, "On", "Off")
End Sub
Private Sub Form1_KeyPress1(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles Me.KeyPress
If onn Then
Select Case e.KeyChar
Case "Z", "z", "X", "x"
mouse_event(&H2, 0, 0, 0, 0)
mouse_event(&H4, 0, 0, 0, 0)
End Select
End If
End Sub
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
Debug.Print("Button2")
End Sub
Private Sub Button3_Click(sender As Object, e As System.EventArgs) Handles Button3.Click
Debug.Print("Button3")
End Sub
End Class

Answer 2

Public Class Iconform
Public Declare Auto Function SetCursorPos Lib "User32.dll" (ByVal X As Integer, ByVal Y As Integer) As Long
Public Declare Auto Function GetCursorPos Lib "User32.dll" (ByRef lpPoint As Point) As Long
Public Declare Sub mouse_event Lib "user32" Alias "mouse_event" (ByVal dwFlags As Long, ByVal dx As Long, ByVal dy As Long, ByVal cButtons As Long, ByVal dwExtraInfo As Long)
Public Const MOUSEEVENTF_LEFTDOWN = &H2 ' left button down
Public Const MOUSEEVENTF_LEFTUP = &H4 ' left button up
Public Const MOUSEEVENTF_MIDDLEDOWN = &H20 ' middle button down
Public Const MOUSEEVENTF_MIDDLEUP = &H40 ' middle button up
Public Const MOUSEEVENTF_RIGHTDOWN = &H8 ' right button down
Public Const MOUSEEVENTF_RIGHTUP = &H10 ' right button up
Private Sub NotifyIcon1_MouseDoubleClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles NotifyIcon1.Click
SettingsForm.Show()
End Sub
Private Sub OptionsToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OptionsToolStripMenuItem.Click
SettingsForm.Show()
End Sub
Private Sub CloseToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CloseToolStripMenuItem.Click
Me.Close()
End Sub
Private Sub Form1_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles MyBase.KeyDown
Dim bHandled As Boolean = False
Dim xPos As Integer = Windows.Forms.Cursor.Position.X.ToString
Dim zPos As Integer = Windows.Forms.Cursor.Position.Y.ToString
Select Case e.KeyCode
Case Keys.Right
Windows.Forms.Cursor.Position = New Point(xPos + 10, zPos)
Case Keys.Left
Windows.Forms.Cursor.Position = New Point(xPos - 10, zPos)
Case Keys.Down
Windows.Forms.Cursor.Position = New Point(xPos, zPos + 10)
Case Keys.Up
Windows.Forms.Cursor.Position = New Point(xPos, zPos - 10)
Case Keys.D
mouse_event(MOUSEEVENTF_LEFTDOWN, 0, 0, 0, 0)
End Select
End Sub
End Class

Answer 3

Try using the PerformClick() method:
Button1.PerformClick()
In your code it could be like:
If onn And (e.KeyChar = "Z" Or e.KeyChar = "X" Or e.KeyChar = "z" Or e.KeyChar = "x") Then
Button1.PerformClick()
End If