Graphics.DrawLine() Method is used to draw a line connecting the two points specified by the coordinate pairs. There are 4 methods in the overload list of this method as follows:
- DrawLine(Pen, PointF, PointF) Method
- DrawLine(Pen, Int32, Int32, Int32, Int32) Method
- DrawLine(Pen, Single, Single, Single, Single) Method
- DrawLine(Pen, Point, Point) Method
Here, we will discuss the first two methods.
DrawLine(Pen, PointF, PointF) Method
This method is used to draw line form a specified set of points to a specified set of points. It needs a PointF variable which is set of (x, y) points.
Syntax:
public void DrawLine (System.Drawing.Pen pen, System.Drawing.PointF pt1, System.Drawing.PointF pt2);
Parameters:
- pen: Pen determines the color, width, and style of the line.
- pt1: Defines the (x, y) coordinates as a PointF variable of the initial point.
- pt2: Defines the (x, y) coordinates as a PointF variable of the final point.
Exception: This method will give ArgumentNullexception if the pen is null.
Example:
// C# program to demonstrate the // DrawLine(Pen, PointF, PointF) Methodusing System;using System.Drawing;using System.Drawing.Printing;using System.Windows.Forms; namespace GFG { class PrintableForm : Form { public static void Main() { Application.Run(new PrintableForm()); } public PrintableForm() { ResizeRedraw = true; } protected override void OnPaint(PaintEventArgs pea) { // Defines pen Pen pen = new Pen(ForeColor); // Defines the both points to connect // pt1 is (30.0, 30.0) which represents (x1, y1) PointF pt1 = new PointF(30.0F, 30.0F); // pt2 is (200.0, 300.0) which represents (x2, y2) PointF pt2 = new PointF(200.0F, 300.0F); // Draws the line pea.Graphics.DrawLine(pen, pt1, pt2); }}} |
Output:
DrawLine(Pen, Int32, Int32, Int32, Int32) Method
This method is used to draw line form a specified set of coordinates given in form x1, y1, x2, y2 all discrete.
Syntax:
public void DrawLine (System.Drawing.Pen pen, int x1, int y1, int x2, int y2);
Parameters:
- pen: Pen determines the color, width, and style of the line.
- x1: The abscissa of first point.
- y1: The ordinate of first point.
- x2: The abscissa of second point.
- y2: The ordinate of second point.
Exception: This method will give ArgumentNullexception if the pen is null.
Example 1:
// C# program to draw a cross using the// DrawLine(Pen, Int32, Int32, Int32,// Int32) Methodusing System;using System.Drawing;using System.Drawing.Printing;using System.Windows.Forms; namespace GFG { class PrintableForm : Form { public static void Main() { Application.Run(new PrintableForm()); } public PrintableForm() { ResizeRedraw = true; } protected override void OnPaint(PaintEventArgs pea) { // Defines the pen Pen pen = new Pen(ForeColor); // To draw a cross we need to make 2 // diagonals from top-left to the // bottom-right and top-right to the // bottom-left to calculate these // coordinates we would take help of // our screen size top-left = (0, 0) // bottom-right = (ClientSize.Width - 1, // ClientSize.Height - 1) // top-right = (ClientSize.Width - 1, 0) // bottom-left = (0, ClientSize.Height - 1) pea.Graphics.DrawLine(pen, 0, 0, ClientSize.Width - 1, ClientSize.Height - 1); pea.Graphics.DrawLine(pen, ClientSize.Width - 1, 0, 0, ClientSize.Height - 1); }}} |
Output:
Example 2:
// C# program to Create a 8x8 square board// using // DrawLine(Pen, Int32, Int32, Int32,// Int32) Methodusing System;using System.Drawing;using System.Drawing.Printing;using System.Windows.Forms; namespace GFG { class PrintableForm : Form { public static void Main() { Application.Run(new PrintableForm()); } public PrintableForm() { ResizeRedraw = true; } protected override void OnPaint(PaintEventArgs pea) { // Define Pen Pen pen = new Pen(ForeColor); // loop for all 7 horizontal lines to draw for (int i = 0; i < 7; i++) { // Taking Block size to be 30x30 // So width and height will be 30*8=240 pea.Graphics.DrawLine(pen, i * 30, 0, i * 30, 240); } // loop for all 7 horizontal lines to draw for (int i = 0; i < 7; i++) { pea.Graphics.DrawLine(pen, 0, i * 30, 240, i * 30); } }}} |
Output:
