Drawing Help

[ejazmusavi]

Hi every one!
i want to make a drawing programm in c# like ms paint in windows. I want to draw line, rectangle, square, ellipse and other objects on mouse move and mouse up events and fill them with colour.
To do this from where i have to start? any tutorials or ebook or sample projects. pls rply

[ddanbe]

Start simple. Can you draw a line, rectangle a circle on a form? If not, try to do that first.

[ejazmusavi]

thnx for ur kind response.
i can draw line, rectangle, circle and every thing(fixed size) on form. but i have no idea to draw these object on mouse events.(up, down and move)
once again thanx.

[ddanbe]

Here is some code I am still working on.
It shows how to draw a rectangle during a mousemove, while the left mouse button is still down.

using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;

namespace ScreenCapture
{
    public partial class TransparantFoil : Form
    {
        private Form _master;
        private Point _FirstClickPt;
        private Point _TopLeftPt, _BottomRightPt;
        private Graphics _G;
        private Pen _Pen;
        private Pen _Erase;

        public TransparantFoil() {}

        public TransparantFoil(Form M)
        {
            InitializeComponent();
            _master = M;
            _FirstClickPt = new Point();
            _TopLeftPt = new Point();
            _BottomRightPt = new Point();
            _G = CreateGraphics();
            _Pen = new Pen(Color.DarkBlue);
            _Erase = new Pen(this.BackColor);
            //(Cursor)(ScreenCapture.Properties.Resources.viser);// myCursor;
        }
   
        private void TransparantFoil_MouseDown(object sender, MouseEventArgs e)
        {
            _FirstClickPt.X = e.X;
            _FirstClickPt.Y = e.Y;
        }

        private void TransparantFoil_MouseMove(object sender, MouseEventArgs e)
        {           
            if (e.Button == MouseButtons.Left) //only do something if left mouse btn clicked
            {
                //Erase previous rectangle
                _G.DrawRectangle(_Erase, _TopLeftPt.X, _TopLeftPt.Y, 
                    _BottomRightPt.X - _TopLeftPt.X, _BottomRightPt.Y - _TopLeftPt.Y);

                //Determine X coordinates
                if (Cursor.Position.X < _FirstClickPt.X)    //moved left
                {
                    _TopLeftPt.X = Cursor.Position.X;
                    _BottomRightPt.X = _FirstClickPt.X;
                }
                else
                {
                    _TopLeftPt.X = _FirstClickPt.X;
                    _BottomRightPt.X = Cursor.Position.X;
                }

                //Determine Y coordinates
                if (Cursor.Position.Y < _FirstClickPt.Y)    //moved up
                {
                    _TopLeftPt.Y = Cursor.Position.Y;
                    _BottomRightPt.Y = _FirstClickPt.Y;
                }
                else
                {
                    _TopLeftPt.Y = _FirstClickPt.Y;
                    _BottomRightPt.Y = Cursor.Position.Y;
                }

                //Draw a new rectangle
                _G.DrawRectangle(_Pen, _TopLeftPt.X, _TopLeftPt.Y,
                    _BottomRightPt.X - _TopLeftPt.X, _BottomRightPt.Y - _TopLeftPt.Y);
            }
        }

        private void TransparantFoil_MouseUp(object sender, MouseEventArgs e)
        {
            this.Hide();        //hide our foil
            DialogResult result = saveFileDlg.ShowDialog();
            if (result == DialogResult.OK)
            {
               SaveCapture(saveFileDlg.FileName);
            }          
            _master.Show();     //show the master control panel again
        }

        private void TransparantFoil_FormClosing(object sender, FormClosingEventArgs e)
        {
            _G.Dispose();
        }

        private void SaveCapture(string Fname)
        {
            Rectangle ImageBounds = new Rectangle(_TopLeftPt.X, _TopLeftPt.Y,
                _BottomRightPt.X - _TopLeftPt.X, _BottomRightPt.Y - _TopLeftPt.Y);
            Bitmap bitmap = new Bitmap(ImageBounds.Width, ImageBounds.Height);
            Graphics G = Graphics.FromImage(bitmap);    //Create Graphics object from the bitmap
            G.CopyFromScreen(_TopLeftPt, Point.Empty, ImageBounds.Size);
            bitmap.Save(Fname, ImageFormat.Bmp);
        }
    }
}

[ejazmusavi]

thnx it is enough for basic. but what i have to do if i want to resize, select, move or fill any drawn object.
thnx

[Geekitygeek]

if you want to be able to alter something after it is drawn you will need to store each object you draw in some way. I would recommend creating some classes. Create a base class for drawn objects that stores common details (location, colour, etc) then create some subclasses which inherit from that class to store details specific to different types of object:

public class DrawnItem
    {
        public Color color { get; set; }
        public Point location { get; set; }
        //etc
    }
    public class DrawnCircle : DrawnItem
    {
        public int radius { get; set; }
        //etc
    }

Each time you draw a new item, add it to a List. That way you have a record of the items you have added to the drawing area.

If you dont maintain a record of each item you will have no way to distinguish them ocne they are drawn to the screen.

[ejazmusavi]

thank You.
Explain some thing more about this
or any example please.
Once again thank

[poifull]

Hi,

I need to draw lines in a C# web form. How do i do it?

[ddanbe]

@poifull do not resurrect old threads! Start a new one with your question, and of course you may always refer to this one.

[kvprajapati]

Thanks @poifull and @danny.

@poifull has created a new thread.

Thread locked.