Como: Desenhar uma forma de contornada

Artigo
08/25/2010

Este exemplo desenha um contornos de elipses e retângulos em um formulário.

Exemplo

Private Sub DrawEllipse()
    Dim myPen As New System.Drawing.Pen(System.Drawing.Color.Red)
    Dim formGraphics As System.Drawing.Graphics
    formGraphics = Me.CreateGraphics()
    formGraphics.DrawEllipse(myPen, New Rectangle(0, 0, 200, 300))
    myPen.Dispose()
    formGraphics.Dispose()
End Sub

Private Sub DrawRectangle()
    Dim myPen As New System.Drawing.Pen(System.Drawing.Color.Red)
    Dim formGraphics As System.Drawing.Graphics
    formGraphics = Me.CreateGraphics()
    formGraphics.DrawRectangle(myPen, New Rectangle(0, 0, 200, 300))
    myPen.Dispose()
    formGraphics.Dispose()
End Sub

private void DrawEllipse()
{
    System.Drawing.Pen myPen = new System.Drawing.Pen(System.Drawing.Color.Red);
    System.Drawing.Graphics formGraphics;
    formGraphics = this.CreateGraphics();
    formGraphics.DrawEllipse(myPen, new Rectangle(0, 0, 200, 300));
    myPen.Dispose();
    formGraphics.Dispose();
}

private void DrawRectangle()
{
    System.Drawing.Pen myPen = new System.Drawing.Pen(System.Drawing.Color.Red);
    System.Drawing.Graphics formGraphics;
    formGraphics = this.CreateGraphics();
    formGraphics.DrawRectangle(myPen, new Rectangle(0, 0, 200, 300));
    myPen.Dispose();
    formGraphics.Dispose();
}

private:
    void DrawEllipse()
    {
        System::Drawing::Pen^ myPen =
            gcnew System::Drawing::Pen(System::Drawing::Color::Red);
        System::Drawing::Graphics^ formGraphics;
        formGraphics = this->CreateGraphics();
        formGraphics->DrawEllipse(myPen, Rectangle(0, 0, 200, 300));
        delete myPen;
        delete formGraphics;
    }

private:
    void DrawRectangle()
    {
        System::Drawing::Pen^ myPen =
            gcnew System::Drawing::Pen(System::Drawing::Color::Red);
        System::Drawing::Graphics^ formGraphics;
        formGraphics = this->CreateGraphics();
        formGraphics->DrawRectangle(myPen, Rectangle(0, 0, 200, 300));
        delete myPen;
        delete formGraphics;
    }

Compilando o código

Não é possível telefonar esse método no Load manipulador de eventos. O conteúdo desenhado não irá ser redesenhado se o formulário for redimensionado ou obscurecido por outro formulário.Para tornar seu conteúdo automaticamente redesenhado, você deve substituir o OnPaint método.