ControlPaint.DrawReversibleLine(Point, Point, Color) Method

Definition

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Draws a reversible line on the screen within the specified starting and ending points and with the specified background color.

public:
 static void DrawReversibleLine(System::Drawing::Point start, System::Drawing::Point end, System::Drawing::Color backColor);

public static void DrawReversibleLine (System.Drawing.Point start, System.Drawing.Point end, System.Drawing.Color backColor);

static member DrawReversibleLine : System.Drawing.Point * System.Drawing.Point * System.Drawing.Color -> unit

Public Shared Sub DrawReversibleLine (start As Point, end As Point, backColor As Color)

Parameters

start

Point

The starting Point of the line, in screen coordinates.

end

Point

The ending Point of the line, in screen coordinates.

backColor

Color

The Color of the background behind the line.

Examples

The following code example demonstrates using the ControlPaint.DrawReversibleLine and Control.PointToScreen methods. To run the example, paste the following code in a form. Add a button named Button3 to the form and ensure all events are connected to their event handlers.

// When the mouse hovers over Button3, two reversible lines are 
// drawn using the corner coordinates of Button3, which are first 
// converted to screen coordinates.
void Button3_MouseHover( Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
   ControlPaint::DrawReversibleLine( Button3->PointToScreen( Point(0,0) ), Button3->PointToScreen( Point(Button3->ClientRectangle.Right,Button3->ClientRectangle.Bottom) ), SystemColors::Control );
   ControlPaint::DrawReversibleLine( Button3->PointToScreen( Point(Button3->ClientRectangle.Right,Button3->ClientRectangle.Top) ), Button3->PointToScreen( Point(Button1->ClientRectangle.Left,Button3->ClientRectangle.Bottom) ), SystemColors::Control );
}

// When the mouse moves from Button3, the reversible lines are erased by
// using the same coordinates as are used in the Button3_MouseHover method.
void Button3_MouseLeave( Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
   ControlPaint::DrawReversibleLine( Button3->PointToScreen( Point(0,0) ), Button3->PointToScreen( Point(Button3->ClientRectangle.Right,Button3->ClientRectangle.Bottom) ), SystemColors::Control );
   ControlPaint::DrawReversibleLine( Button3->PointToScreen( Point(Button3->ClientRectangle.Right,Button3->ClientRectangle.Top) ), Button3->PointToScreen( Point(Button3->ClientRectangle.Left,Button3->ClientRectangle.Bottom) ), SystemColors::Control );
}

// When the mouse hovers over Button3, two reversible lines are 
// drawn using the corner coordinates of Button3, which are first 
// converted to screen coordinates.
private void Button3_MouseHover(object sender, System.EventArgs e)
{
    ControlPaint.DrawReversibleLine(Button3.PointToScreen(
        new Point(0, 0)), Button3.PointToScreen(
        new Point(Button3.ClientRectangle.Right, 
        Button3.ClientRectangle.Bottom)), SystemColors.Control);
    
    ControlPaint.DrawReversibleLine(Button3.PointToScreen(
        new Point(Button3.ClientRectangle.Right, 
        Button3.ClientRectangle.Top)), 
        Button3.PointToScreen(new Point(Button1.ClientRectangle.Left, 
        Button3.ClientRectangle.Bottom)), SystemColors.Control);
}

// When the mouse moves from Button3, the reversible lines are erased by
// using the same coordinates as are used in the Button3_MouseHover method.
private void Button3_MouseLeave(object sender, System.EventArgs e)
{
    ControlPaint.DrawReversibleLine(Button3.PointToScreen(
        new Point(0, 0)), Button3.PointToScreen(
        new Point(Button3.ClientRectangle.Right, 
        Button3.ClientRectangle.Bottom)), SystemColors.Control);
    
    ControlPaint.DrawReversibleLine(Button3.PointToScreen(
        new Point(Button3.ClientRectangle.Right, 
        Button3.ClientRectangle.Top)), 
        Button3.PointToScreen(new Point(Button3.ClientRectangle.Left,
        Button3.ClientRectangle.Bottom)), SystemColors.Control);
}

' When the mouse hovers over Button3, two reversible lines are drawn
' using the corner coordinates of Button3, which are first 
' converted to screen coordinates.
Private Sub Button3_MouseHover(ByVal sender As Object, _
    ByVal e As System.EventArgs) Handles Button3.MouseHover

    ControlPaint.DrawReversibleLine(Button3.PointToScreen(New Point(0, 0)), _
    Button3.PointToScreen(New Point(Button3.ClientRectangle.Right, _
        Button3.ClientRectangle.Bottom)), SystemColors.Control)
    ControlPaint.DrawReversibleLine(Button3.PointToScreen( _
        New Point(Button3.ClientRectangle.Right, Button3.ClientRectangle.Top)), _
       Button3.PointToScreen(New Point _
            (Button1.ClientRectangle.Left, Button3.ClientRectangle.Bottom)), _
            SystemColors.Control)
End Sub

' When the mouse moves from Button3, the reversible lines are 
' erased by using the same coordinates as are used in the
' Button3_MouseHover method.
Private Sub Button3_MouseLeave(ByVal sender As Object, _
    ByVal e As System.EventArgs) Handles Button3.MouseLeave

    ControlPaint.DrawReversibleLine(Button3.PointToScreen(New Point(0, 0)), _
    Button3.PointToScreen(New Point(Button3.ClientRectangle.Right, _
        Button3.ClientRectangle.Bottom)), SystemColors.Control)
    ControlPaint.DrawReversibleLine(Button3.PointToScreen( _
        New Point(Button3.ClientRectangle.Right, Button3.ClientRectangle.Top)), _
       Button3.PointToScreen(New Point(Button3.ClientRectangle.Left, _
       Button3.ClientRectangle.Bottom)), SystemColors.Control)
End Sub

Remarks

The backColor parameter is used to calculate the fill color of the line so that it is always visible against the background.

The results of this method can be reversed by drawing the same line again. Drawing a line using this method is similar to inverting a region of the screen, except that it provides better performance for a wider variety of colors.

See also

• FrameStyle