Search
Module:
Directory

   Desktop Functions:

   Smart Device Functions:


Show Recent Changes
Subscribe (RSS)
Misc. Pages
Comments
FAQ
Helpful Tools
Playground
Suggested Reading
Website TODO List
Support Forum
Download Visual Studio Add-In

Terms of Use
Privacy Policy
mouse_event (user32)
 
.
Summary
The mouse_event API

C# Signature:

[DllImport("user32.dll")]
static extern void mouse_event(uint dwFlags, uint dx, uint dy, uint dwData,
   UIntPtr dwExtraInfo);

or

[DllImport("user32.dll")]
static extern void mouse_event(uint dwFlags, uint dx, uint dy, uint dwData,
  int dwExtraInfo);

User-Defined Types:

  [Flags]
  public enum MouseEventFlags
  {
    LEFTDOWN   = 0x00000002,
    LEFTUP     = 0x00000004,
    MIDDLEDOWN = 0x00000020,
    MIDDLEUP   = 0x00000040,
    MOVE       = 0x00000001,
    ABSOLUTE   = 0x00008000,
    RIGHTDOWN  = 0x00000008,
    RIGHTUP    = 0x00000010
  }

VB.Net Signature:

The declaration as originally posted is incorrect as mouse_event does not return a value. Also, for VB.NET, one should really use Int32 to ensure correct sizing. Plus, dwExtraInfo appears to be a ULONG_PTR in C++ (IntPtr in VB.NET)

Original:

Declare Auto Function mouse_event Lib "user32.dll" (ByVal dwflags As Integer, ByVal dx As Integer, ByVal dy As Integer, ByVal dwData As Integer, ByVal dwExtraInfo As Integer) As Integer

Fixed:

Declare Auto Sub mouse_event Lib "user32.dll" (ByVal dwFlags As Int32, ByVal dx As Int32, ByVal dy As Int32, ByVal cButtons As Int32, ByVal dwExtraInfo As IntPtr)

Notes:

FYI, Microsoft tells us for "Windows NT/2000/XP: This function has been superseded. Use SendInput instead."

Original contributor tells us:

I wanted to emulate the scroll. Searching for this information wasn't easy ... but here is how you do the mouse scroll button

dim ScrollValue as Integer

ScrollValue = 120 'or -120 for up or down scrolling

mouse_event(&H800, 0, 0, ScrollValue, 0)

Tips & Tricks:

Please add some!

C# Sample Code:

[DllImport("user32.dll")]
static extern bool SetCursorPos(int X, int Y);  

[DllImport("user32.dll")]
static extern void mouse_event(uint dwFlags, uint dx, uint dy, uint dwData,  int dwExtraInfo);

[Flags]
  public enum MouseEventFlags
  {
    LEFTDOWN   = 0x00000002,
    LEFTUP     = 0x00000004,
    MIDDLEDOWN = 0x00000020,
    MIDDLEUP   = 0x00000040,
    MOVE       = 0x00000001,
    ABSOLUTE   = 0x00008000,
    RIGHTDOWN  = 0x00000008,
    RIGHTUP    = 0x00000010
  }
...
//Set cursor position  
SetCursorPos(10, 50);
//Mouse Right Down and Mouse Right Up
mouse_event((uint)MouseEventFlags.RIGHTDOWN,0,0,0,0);
mouse_event((uint)MouseEventFlags.RIGHTUP,0,0,0,0);    

VB.NET 2005 Sample Code:

Based on http://vb-helper.com/howto_move_click_mouse.html

This code assumes a form called frmMain with a command button called cmdClick a picture box called picClicker and a text box called txtResults

Note Twips are no more. Also, I stripped the FOR loop of delta moves from the command button click to the middle of the picture box.

Option Explicit On

Friend Class frmMain

    Inherits System.Windows.Forms.Form

    Declare Auto Sub mouse_event Lib "user32" (ByVal dwFlags As Int32, ByVal dx As Int32, ByVal dy As Int32, ByVal cButtons As Int32, ByVal dwExtraInfo As IntPtr)

    Const MOUSEEVENTF_MOVE As Int32 = &H1 '  mouse move
    Const MOUSEEVENTF_LEFTDOWN As Int32 = &H2 '  left button down
    Const MOUSEEVENTF_LEFTUP As Int32 = &H4 '  left button up
    Const MOUSEEVENTF_RIGHTDOWN As Int32 = &H8 '  right button down
    Const MOUSEEVENTF_RIGHTUP As Int32 = &H10 '  right button up
    Const MOUSEEVENTF_MIDDLEDOWN As Int32 = &H20 '  middle button down
    Const MOUSEEVENTF_MIDDLEUP As Int32 = &H40 '  middle button up
    Const MOUSEEVENTF_ABSOLUTE As Int32 = &H8000 '  absolute move
    Const MOUSEEVENTF_WHEEL As Int32 = &H800 ' wheel button rolled

    ' Simulate moving the mouse to the center of the
    ' PictureBox and clicking.
    Private Sub cmdClick_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles cmdClick.Click
    Dim cur_x As Single
    Dim cur_y As Single
    Dim dest_x As Single
    Dim dest_y As Single

    ' mouse_event moves in a coordinate system where
    ' (0, 0) is in the upper left corner and
    ' (65535,65535) is in the lower right corner.

    ' Get the current mouse coordinates and convert
    ' them into this new system.
    cur_x = System.Windows.Forms.Cursor.Position.X * 65535 / System.Windows.Forms.Screen.PrimaryScreen.Bounds.Width
    cur_y = System.Windows.Forms.Cursor.Position.Y * 65535 / System.Windows.Forms.Screen.PrimaryScreen.Bounds.Height

    ' Convert the coordinates of the center of the
    ' picClicker PictureBox into this new system.
    Dim pt As Point = picClicker.PointToScreen(New Point(picClicker.ClientRectangle.Width / 2, picClicker.ClientRectangle.Height / 2))

    dest_x = pt.X * 65535 / System.Windows.Forms.Screen.PrimaryScreen.Bounds.Width
    dest_y = pt.Y * 65535 / System.Windows.Forms.Screen.PrimaryScreen.Bounds.Height

    txtResults.Text = txtResults.Text & "From " & System.Windows.Forms.Cursor.Position.X & " " & System.Windows.Forms.Cursor.Position.Y & " to " & pt.X & " " & pt.Y & vbCrLf
    txtResults.Text = txtResults.Text & "From " & cur_x & " " & cur_y & " to " & dest_x & " " & dest_y & vbCrLf

    ' Move the mouse to its final destination and click it.
    mouse_event(MOUSEEVENTF_ABSOLUTE + MOUSEEVENTF_MOVE + MOUSEEVENTF_LEFTDOWN + MOUSEEVENTF_LEFTUP, dest_x, dest_y, 0, 0)
    End Sub

    Private Sub picClicker_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles picClicker.Click
    txtResults.Text = txtResults.Text & "MouseClick" & vbCrLf
    End Sub

    Private Sub picClicker_MouseDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles picClicker.MouseDown
    txtResults.Text = txtResults.Text & "MouseDown (" & e.X & ", " & e.Y & ")" & vbCrLf
    End Sub

    Private Sub picClicker_MouseUp(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles picClicker.MouseUp
    txtResults.Text = txtResults.Text & "MouseUp (" & e.X & ", " & e.Y & ")" & vbCrLf
    End Sub

End Class

Alternative Managed API:

Per http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndotnet/html/win32map.asp , mouse_event is supposed to be replaced by .NET Framework API System.Windows.Forms.MouseEventArgs but this is not the case. MouseEventArgs is just a data structure w/out event capability. I tried to get:

Dim eMouse As New System.Windows.Forms.MouseEventArgs(Windows.Forms.MouseButtons.Left, 1, pt.X, pt.Y, 0)

Me.OnMouseDown(eMouse)

Me.OnMouseMove(eMouse)

Me.OnMouseUp(eMouse)

to work as desired. Although it did trigger mouse events in the form showing the movement and click action desired, it didn't move the mouse pointer on the screen nor did it trigger events in the picture box located at pt.X, pt.Y

Thus I have resigned myself to unmanaged code for now. I will post the SendInput version shortly as mouse_event has been deprecated by Bill in favor of SendInput.

As the original contributor noted:

You can use the System.Windows.Forms.Cursor.Position property to set the position of the mouse, if you would like.

You will note I have replaced the GetCursorPos calls in the original VB source with this as suggested in the MSDN URL I mention above.

Documentation
mouse_event on MSDN

Please edit this page!

Do you have...

  • helpful tips or sample code to share for using this API in managed code?
  • corrections to the existing content?
  • variations of the signature you want to share?
  • additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).

 
Access PInvoke.net directly from VS:
Terms of Use
Find References
Show Printable Version
Revisions