Graphics::DrawClosedCurve Method (Pen^, array<PointF>^)


Draws a closed cardinal spline defined by an array of PointF structures.

Namespace:   System.Drawing
Assembly:  System.Drawing (in System.Drawing.dll)

void DrawClosedCurve(
	Pen^ pen,
	array<PointF>^ points


Type: System.Drawing::Pen^

Pen that determines the color, width, and height of the curve.

Type: array<System.Drawing::PointF>^

Array of PointF structures that define the spline.

Exception Condition

pen is null.


points is null.

This method draws a closed cardinal spline that passes through each point in the array. If the last point does not match the first point, an additional curve segment is added from the last point to the first point to close it.

The array of points must contain at least four PointF structures.

This method uses a default tension of 0.5.

The following code example is designed for use with Windows Forms, and it requires PaintEventArgse, which is a parameter of the Paint event handler. The code performs the following actions:

  • Creates red and green pens.

  • Creates seven points to define a curve.

  • Draws seven red straight lines between the seven points to form a closed polygon.

  • Draws a green closed curve through the seven points.

The method uses a default tension of 0.5.

   void DrawClosedCurvePointF( PaintEventArgs^ e )
      // Create pens.
      Pen^ redPen = gcnew Pen( Color::Red,3.0f );
      Pen^ greenPen = gcnew Pen( Color::Green,3.0f );

      // Create points that define curve.
      PointF point1 = PointF(50.0F,50.0F);
      PointF point2 = PointF(100.0F,25.0F);
      PointF point3 = PointF(200.0F,5.0F);
      PointF point4 = PointF(250.0F,50.0F);
      PointF point5 = PointF(300.0F,100.0F);
      PointF point6 = PointF(350.0F,200.0F);
      PointF point7 = PointF(250.0F,250.0F);
      array<PointF>^ curvePoints = {point1,point2,point3,point4,point5,point6,point7};

      // Draw lines between original points to screen.
      e->Graphics->DrawLines( redPen, curvePoints );

      // Draw closed curve to screen.
      e->Graphics->DrawClosedCurve( greenPen, curvePoints );

.NET Framework
Available since 1.1
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