The creating a graphical object c# презентация

Graphics Graphics The creating a graphical object Syntax: Graphics g=Graphics.FromHwnd(this.Handle); Graphics –an object type where we'll draw. It may be Windows Form. g –name of graphical object; Graphics.FromHwnd(this.Handle) – class method that returns a Handle to Windows Form.

Pen Pen The pens are used for graphical figures drawing. The templates pens: Pen pen1 = Pens.Black; Here: Pen – class “Pen”; pen1 – name of class Pen object; Pens – class of pen objects. We select a pen from this class; Black – a colour of pen that is selected. In this case you can select only a colour. A line width equal to one pixel. A Line style is continuous line.

The pens that are not templates The pens that are not templates Their properties may be set up. Pen pen2 = new Pen(Color.Red); pen2.Width=3; A choice of line style: Styles: Dot, Dash, DashDot, DashDotDot. An example to set up line style: pen2.DashStyle= System.Drawing.Drawing2D.DashStyle.DashDotDot;

Brush Brush A brush is used to flood graphical figures. There are some brush types: Brush – it’s simple brush to flood by one colour; HatchBrush - to hatch; LinearGradientBrush - a brush with linear gradient filling up; PathGradientBrush - a brush with linear gradient in case a colour changes by jumps.

The simple brushes are selected from Brushes class: The simple brushes are selected from Brushes class: Brush brush1=Brushes.Blue; Brush – class name; brush1 – object name; Brushes –class of objects for selecting the brush; Blue –brush colour. In this case you can select only a colour.

The brush for hatching may be selected from HatchBrushes class. For accessing to HatchBrushes class and to styles of hatching it's necessary to add: The brush for hatching may be selected from HatchBrushes class. For accessing to HatchBrushes class and to styles of hatching it's necessary to add: using System.Drawing.Drawing2D; Styles of hatching: CROSS, DiagonalCross, ForwardDiagonal, BackwardDiagonal.

An example of hatching by CROSS style: An example of hatching by CROSS style: HatchBrush brush2 = new HatchBrush(HatchStyle.Cross,ForeColor, BackColor); It's possible to create a pen that draws by brush: Brush brush1=Brushes.Blue;  Pen pen1=new Pen(brush1);

The method for drawing a text in Windows Form The method for drawing a text in Windows Form DrawString(S, Font, Brush, float xleftTop, float yLeftTop); S- row of symbols; The Font class is used for selecting font; float xleftTop, float yLeftTop - the coordinates x, y of left upper corner of rectangle that is used for placing the text. These coordinates are defined by identifiers. Brush brush1=Brushes.Red; float a=100,b=200; Font myFont=new Font(“Tahoma",14); g .DrawString("You are\n welcome!", myFont, brush1, a, b);

The drawing of rectangles The drawing of rectangles DrawRectangle(pen, int x1, int y1, int x2, int y2); x1, y1, x2, y2 –the coordinates of left upper corner and right bottom corner of rectangle. Example: g.DrawRectangle(pen1,50,50,100,100); There is a variant with float type coordinates . DrawRectangle(pen, float xLeft, float yTop, float Height, float Width); xLeft, yTop- the coordinates x, y of left upper corner. Height, Width - height and width of rectangle.

The example of graphics program The example of graphics program There is a choice of pen and its parameters: Color, Width and Line style. Also a font is set and used to display a symbols string. Besides of there is HatchBrush that is used to fill a rectangle.

It’s necessary to create a Handler for button1. It’s necessary to create a Handler for button1. There are two modes how to do it: 1) Select button1/pop up menu/View Code; 2) To do double click on button1. In any case a handler template will appear. It must be filled

You are going to use DashStyle for pen and HatchBrush. So it's necessary to add using System.Drawing.Drawing2D; Don't forget! You are going to use DashStyle for pen and HatchBrush. So it's necessary to add using System.Drawing.Drawing2D; Don't forget!

using System; using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Drawing.Drawing2D;// Don’t forget to add ! using System.Text; using System.Windows.Forms; namespace grafprac1 { public partial class Form1 : Form { public Form1() { InitializeComponent(); }

Now do the next task: Now do the next task: Create a C# program using Windows Form. Place any text in this Form in any place. A brush is used for drawing. Its color is Blue. Font is " Tahoma". Its size equal 12.