docs-desktop/dotnet-desktop-guide/framework/winforms/advanced/how-to-use-a-pen-to-draw-rectangles.md

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title	ms.date	dev_langs	helpviewer_keywords	ms.assetid
How to: Use a Pen to Draw Rectangles	03/30/2017	csharp vb	rectangles [Windows Forms], drawing pens [Windows Forms], drawing rectangles	54a7fa14-3ad8-4d64-b424-2a12005b250c

How to: Use a Pen to Draw Rectangles

To draw rectangles, you need a xref:System.Drawing.Graphics object and a xref:System.Drawing.Pen object. The xref:System.Drawing.Graphics object provides the xref:System.Drawing.Graphics.DrawRectangle%2A method, and the xref:System.Drawing.Pen object stores features of the line, such as color and width.

Example

The following example draws a rectangle with its upper-left corner at (10, 10). The rectangle has a width of 100 and a height of 50. The second argument passed to the xref:System.Drawing.Pen.%23ctor%2A constructor indicates that the pen width is 5 pixels.

When the rectangle is drawn, the pen is centered on the rectangle's boundary. Because the pen width is 5, the sides of the rectangle are drawn 5 pixels wide, such that 1 pixel is drawn on the boundary itself, 2 pixels are drawn on the inside, and 2 pixels are drawn on the outside. For more details on pen alignment, see How to: Set Pen Width and Alignment.

The following illustration shows the resulting rectangle. The dotted lines show where the rectangle would have been drawn if the pen width had been one pixel. The enlarged view of the upper-left corner of the rectangle shows that the thick black lines are centered on those dotted lines.

[!code-csharpSystem.Drawing.UsingAPen#21] [!code-vbSystem.Drawing.UsingAPen#21]

Compiling the Code

The preceding example is designed for use with Windows Forms, and it requires xref:System.Windows.Forms.PaintEventArgs e, which is a parameter of the xref:System.Windows.Forms.Control.Paint event handler.

See also

• Using a Pen to Draw Lines and Shapes