Detecting a mouse move

Question

Hi,

 

I need to know the status of the mouse whether it is moving or being idle. How can I do that? 

I have tried with form's mouse move event but, it doesn't work if the mouse is on any control.

 

Thanks,

 

Regards,

 

Bobby

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Ayyagari

Answer 1

This is mostly done by saving the last point of the mouse and check if that is the same with the previous mouse down 

You see it done on this page on our website

http://www.vb-tips.com/MoveControl.aspx

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Success
Cor

Answer 2

You can create a sinlge mousemove event handler and tie each of the mouse move events from your controls to the one handler event.  This can be done by nominating each control, or by iterating through the form's control colelction.

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        AddHandler Me.MouseMove, AddressOf All_MouseMove
        AddHandler Button1.MouseMove, AddressOf All_MouseMove
        AddHandler ListBox1.MouseMove, AddressOf All_MouseMove
        AddHandler Label1.MouseMove, AddressOf All_MouseMove
    End Sub

    Private Sub All_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs)
        Dim C As Control = CType(sender, Control)
        Dim P As Point = C.PointToScreen(e.Location)
        Label1.Text = Me.PointToClient(P).ToString
    End Sub

To check whether or not the mouse has moved in a certain time period, use a timer.  Create a flag (a boolean variable).  Each time the mouse moves, set the flag to True to indicate 'there has been movement' .  Each time the timer ticks, check the state of the flag.  If it's false, the mouse hasn't moved since the last timer tick.  If it's true (there has been movement), set the flag to false, ready to be tested in the next timer tick.

Answer 3

Start a new WF app and replace the code on Form1 with:

Public Class Form1
  Dim MouseMoveFilter As New FilterMouseMove
  Protected Overrides Sub OnLoad(e As EventArgs)
    MyBase.OnLoad(e)
    Application.AddMessageFilter(MouseMoveFilter)
    AddHandler MouseMoveFilter.MouseMoving, AddressOf MouseMoving
    MouseMoveFilter.Tmr.Interval = 1000
    MouseMoveFilter.Tmr.Start()
  End Sub
  Sub MouseMoving(Moving As Boolean, Ctrl As String)
    Me.Text = If(Moving, "Moving over " + Ctrl, "Not Moving")
  End Sub
  Class FilterMouseMove
    Implements IMessageFilter
    Friend Event MouseMoving(Moving As Boolean, ControlName As String)
    Friend WithEvents Tmr As New Timer
    Public Function PreFilterMessage(ByRef m As Message) As Boolean _
                                     Implements IMessageFilter.PreFilterMessage
      If m.Msg = 512 Then
        RaiseEvent MouseMoving(True, Control.FromHandle(m.HWnd).Name)
        Tmr.Start()
      End If
      Return False
    End Function
    Private Sub Tmr_Tick(sender As Object, e As EventArgs) Handles Tmr.Tick
      Tmr.Stop()
      RaiseEvent MouseMoving(False, "")
    End Sub
  End Class
End Class


Add some controls and move the cursor over the controls.

Answer 4

Thanks for your replies guys.

 

Hi JohnWein,

 

That code works for me. But, I don't understand what that code does. Can you elaborate that code since I am weak in event handlers.

 

Thanks,

Bobby

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Ayyagari

Answer 5

Thanks for your replies guys.

 

Hi JohnWein,

 

That code works for me. But, I don't understand what that code does. Can you elaborate that code since I am weak in event handlers.

 

Thanks,

Bobby

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Ayyagari

I  use the MouseMoving event to communicate from the child class FilterMouseMove to its parent class Form1.  This is a preferred OOP pattern for communications from chidren to parents.  The filter is the important part of the code for your question.  The rest of the code is for demo purposes.