Wyo VB Lecture Notes

Objective #1: Be able to use theMouseDown, MouseUp, MouseMove, MouseLeave, & MouseEnter methods.

• A MouseDown event occurs when the user presses the mouse button somewhere on the form. The following method displays the coordinates of where the mouse was clicked
  
  Private Sub Form1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseDown
  
     If (e.Button = MouseButtons.Left) Then
        MessageBox.Show("The mouse was clicked at (" + e.X.ToString + ", " + e.Y.ToString + ")")
     End If
  
  End Sub
  
  
• A MouseUp event occurs when the user releases the mouse button. Note that the MouseUp event may occur in the very next instant after its corresponding MouseDown event if the user clicked the mouse quickly. Or, if the user decides to hold down the mouse button for a long time or he/she drags the mouse across the screen, the MouseUp event will occur much later than its corresponding MouseDown event.
  
  
• A MouseMove event occurs when the mouse's position changes. The following method displays the coordinates of the mouse in two labels
  
  Private Sub Form1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseMove
     lblX.Text = e.X
     lblY.Text = e.Y
  End Sub
  
  
• The MouseLeave event occurs when the mouse leaves the form. A MouseEnter event occurs when the mouse enters the forms. See the following examples
  
  Private Sub Form1_MouseLeave(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.MouseLeave
    lblElvis.Text = "Elvis has left the building"
    lblX.Text = ""
    lblY.Text = ""
  End Sub

  Private Sub Form1_MouseEnter(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.MouseEnter
    lblElvis.Text = "Elvis is in the building"
  End Sub