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ControlPaint.DrawReversibleLine(Point, Point, Color) Metodo

Definizione

Disegna una linea reversibile sullo schermo all'interno dei punti iniziale e finale specificati e con il colore di sfondo specificato.

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)

Parametri

start
Point

Oggetto Point iniziale della linea, secondo le coordinate dello schermo.

end
Point

Oggetto Point finale della linea, secondo le coordinate dello schermo.

backColor
Color

Oggetto Color dello sfondo dietro la linea.

Esempio

Nell'esempio di codice seguente viene illustrato l'uso dei ControlPaint.DrawReversibleLine metodi e Control.PointToScreen . Per eseguire l'esempio, incollare il codice seguente in un modulo. Aggiungere un pulsante denominato Button3 al modulo e assicurarsi che tutti gli eventi siano connessi ai gestori eventi.

// 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

Commenti

Il backColor parametro viene usato per calcolare il colore di riempimento della linea in modo che sia sempre visibile sullo sfondo.

I risultati di questo metodo possono essere invertiti disegnando di nuovo la stessa linea. Il disegno di una linea con questo metodo è simile all'inversione di un'area dello schermo, ad eccezione del fatto che offre prestazioni migliori per una varietà di colori più ampia.

Si applica a

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