Control.PointToScreen Method (Point)


The .NET API Reference documentation has a new home. Visit the .NET API Browser on to see the new experience.

Computes the location of the specified client point into screen coordinates.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

Public Function PointToScreen (
	p As Point
) As Point


Type: System.Drawing.Point

The client coordinate Point to convert.

Return Value

Type: System.Drawing.Point

A Point that represents the converted Point, p, in screen coordinates.

The following code example demonstrates how to use the BackColor, RectangleToScreen, PointToScreen, MouseButtons, ControlPaint.DrawReversibleFrame, and Rectangle.IntersectsWith members. To run the example, paste the following code in a form called Form1 containing several controls. This example requires that the MouseDown, MouseMove, and MouseUp events are connected to the event handlers defined in the example.

' The following three methods will draw a rectangle and allow 
' the user to use the mouse to resize the rectangle.  If the 
' rectangle intersects a control's client rectangle, the 
' control's color will change.

Dim isDrag As Boolean = False
Dim theRectangle As New rectangle(New Point(0, 0), New Size(0, 0))
Dim startPoint As Point

Private Sub Form1_MouseDown(ByVal sender As Object, ByVal e As _
    System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseDown

    ' Set the isDrag variable to true and get the starting point 
    ' by using the PointToScreen method to convert form coordinates to
    ' screen coordinates.
    If (e.Button = MouseButtons.Left) Then
        isDrag = True
    End If

    Dim control As Control = CType(sender, Control)

    ' Calculate the startPoint by using the PointToScreen 
    ' method.
    startPoint = control.PointToScreen(New Point(e.X, e.Y))
End Sub

Private Sub Form1_MouseMove(ByVal sender As Object, ByVal e As _
System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseMove

    ' If the mouse is being dragged, undraw and redraw the rectangle
    ' as the mouse moves.
    If (isDrag) Then

        ' Hide the previous rectangle by calling the DrawReversibleFrame 
        ' method with the same parameters.
        ControlPaint.DrawReversibleFrame(theRectangle, Me.BackColor, _

        ' Calculate the endpoint and dimensions for the new rectangle, 
        ' again using the PointToScreen method.
        Dim endPoint As Point = CType(sender, Control).PointToScreen(New Point(e.X, e.Y))
        Dim width As Integer = endPoint.X - startPoint.X
        Dim height As Integer = endPoint.Y - startPoint.Y
        theRectangle = New Rectangle(startPoint.X, startPoint.Y, _
            width, height)

        ' Draw the new rectangle by calling DrawReversibleFrame again.  
        ControlPaint.DrawReversibleFrame(theRectangle, Me.BackColor, _
    End If
End Sub

Private Sub Form1_MouseUp(ByVal sender As Object, ByVal e As _
System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseUp

    ' If the MouseUp event occurs, the user is not dragging.
    isDrag = False

    ' Draw the rectangle to be evaluated. Set a dashed frame style 
    ' using the FrameStyle enumeration.
    ControlPaint.DrawReversibleFrame(theRectangle, Me.BackColor, _

    ' Find out which controls intersect the rectangle and change their color.
    ' The method uses the RectangleToScreen method to convert the 
    ' Control's client coordinates to screen coordinates.
    Dim i As Integer
    Dim controlRectangle As Rectangle
    For i = 0 To Controls.Count - 1
        controlRectangle = Controls(i).RectangleToScreen _
        If controlRectangle.IntersectsWith(theRectangle) Then
            Controls(i).BackColor = Color.BurlyWood
        End If

    ' Reset the rectangle.
    theRectangle = New Rectangle(0, 0, 0, 0)
End Sub

.NET Framework
Available since 1.1
Return to top