C# Tutorial

READING XML FILE:

        private void button1_Click_1(object sender, EventArgs e)

        {

            OpenFileDialog ofd = new OpenFileDialog();

            ofd.Filter = "XML|*.xml";

            if (ofd.ShowDialog() == DialogResult.OK)

            {

                XmlDocument xdoc = new XmlDocument();

                xdoc.Load(ofd.FileName);

                foreach(XmlNode node in xdoc.SelectNodes("People/Person"))

                    MessageBox.Show(node.SelectSingleNode("Name").InnerText);

            }

        }

XML FILE:

<People>

       <Person>

              <Name>Adam</Name>

              <Age>15</Age>

              <Email>google@gmail.com</Email>

       </Person>

       <Person>

              <Name>Zoloo</Name>

              <Age>24</Age>

              <Email>zoloo@gmail.com</Email>

       </Person>

</People>

Editing XML:

        XmlDocument xdoc;

        string path;

        private void button1_Click_1(object sender, EventArgs e)

        {

            OpenFileDialog ofd = new OpenFileDialog();

            ofd.Filter = "XML|*.xml";

            if (ofd.ShowDialog() == DialogResult.OK)

            {

                path = ofd.FileName;

                xdoc = new XmlDocument();

                xdoc.Load(path);

                textBox1.Text = xdoc.SelectSingleNode("People/Person/Name").InnerText;

                numericUpDown1.Value = Convert.ToInt32(xdoc.SelectSingleNode("People/Person/Age").InnerText);

                textBox2.Text = xdoc.SelectSingleNode("People/Person/Email").InnerText;

            }

        }

        private void button2_Click(object sender, EventArgs e)

        {

            xdoc.SelectSingleNode("People/Person/Name").InnerText = textBox1.Text;

            xdoc.SelectSingleNode("People/Person/Age").InnerText = numericUpDown1.Value.ToString();

            xdoc.SelectSingleNode("People/Person/Email").InnerText = textBox2.Text;

            xdoc.Save(path);

        }

DELETING A XML NODE:

        private void button4_Click(object sender, EventArgs e)

        {

            xdoc = new XmlDocument();

            xdoc.Load("xDoc1.xml");

            foreach (XmlNode xnode in xdoc.SelectNodes("People/Person"))

                if (xnode.SelectSingleNode("Name").InnerText == textBox1.Text) xnode.ParentNode.RemoveChild(xnode);

            xdoc.Save("xDoc1.xml");

        }

MD5 AND SHA1:

        private void button1_Click(object sender, EventArgs e)

        {

            // MD5

            MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();

            UTF8Encoding utf8 = new UTF8Encoding();

            MessageBox.Show(BitConverter.ToString(md5.ComputeHash(utf8.GetBytes(textBox1.Text))));

            // SHA1

            SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider();

            MessageBox.Show(BitConverter.ToString(sha1.ComputeHash(utf8.GetBytes(textBox1.Text))));

        }

Drag and Drop:

        private void panel1_DragOver(object sender, DragEventArgs e)

        {

            e.Effect = DragDropEffects.All;

        }

        private void panel1_DragDrop(object sender, DragEventArgs e)

        {

            string[] files = e.Data.GetData(DataFormats.FileDrop) as string[];

            foreach(string s in files)

                MessageBox.Show(s);

        }

Drawing Shapes:

        private void panel1_Click(object sender, EventArgs e)

        {

            SolidBrush sb = new SolidBrush(Color.Green);

            Graphics g = panel1.CreateGraphics();

            g.FillRectangle(sb, 20, 20, 100, 50);

            g.FillEllipse(sb, 100, 100, 50, 50);

            g.FillPie(sb, 150, 150, 60, 60, 0, 270);

        }

Drawing with Pen class:

        private void panel1_Click(object sender, EventArgs e)

        {

            Pen p = new Pen(Color.Red, 3);

            Graphics g = panel1.CreateGraphics();

            g.DrawArc(p, 20, 20, 100, 100, 0, 90);

            g.DrawLine(p, new Point(0, 0), new Point(100, 100));

        }

Drawing Strings Text:

        private void panel1_Click(object sender, EventArgs e)

        {

            SolidBrush sb = new SolidBrush(Color.Blue);

            Pen p = new Pen(Color.Red, 3);

            Graphics g = panel1.CreateGraphics();

            FontFamily ff = new FontFamily("Arial");

            System.Drawing.Font font = new System.Drawing.Font(ff, 16, FontStyle.Italic);

            g.DrawString("Adam", font, sb, new Point(20, 20));

        }

Multiple Colors in a LinearGradientBrush:

        private void panel1_Click(object sender, EventArgs e)

        {

            LinearGradientBrush lgb = new LinearGradientBrush(new Point(20, 20), new Point(20, 70), Color.Red, Color.Yellow);

            SolidBrush sb = new SolidBrush(Color.Blue);

            Pen p = new Pen(Color.Red, 3);

            Graphics g = panel1.CreateGraphics();

            g.FillRectangle(lgb, 20, 20, 50, 50);

            g.FillEllipse(lgb, 100, 100, 100, 100);

// Multiple Colors:

            ColorBlend cb = new ColorBlend();

            cb.Colors = new Color[] { Color.Black, Color.Blue, Color.SkyBlue, Color.White };

            cb.Positions = new float[] { 0, .33F, .66F, 1F };

            lgb.InterpolationColors = cb;

            g.FillRectangle(lgb, 20, 20, 50, 50);

        }

PathGradientBrush :

        private void panel1_Click(object sender, EventArgs e)

        {

            GraphicsPath gp = new GraphicsPath();

            gp.AddEllipse(20, 20, 100, 100);

            PathGradientBrush pgb = new PathGradientBrush(gp);

            pgb.CenterColor = Color.White;

            pgb.SurroundColors = new Color[] { Color.Black };

            Graphics g = panel1.CreateGraphics();

            g.FillEllipse(pgb, 20, 20, 100, 100);

        }

CAPTURING SCREEN

        private void button1_Click(object sender, EventArgs e)

        {

            // screen

            /*

            Bitmap b = new Bitmap(Screen.PrimaryScreen.WorkingArea.Width, Screen.PrimaryScreen.WorkingArea.Height);

            Graphics g = Graphics.FromImage(b);

            g.CopyFromScreen(Point.Empty, Point.Empty, Screen.PrimaryScreen.WorkingArea.Size);

            pictureBox1.Image = b;

             */

            Thread t = new Thread(Blah);

            t.Start();

        }

        void Blah()

        {

            for (; ; )

            {

                Bitmap b = new Bitmap(Screen.PrimaryScreen.WorkingArea.Width, Screen.PrimaryScreen.WorkingArea.Height);

                Graphics g = Graphics.FromImage(b);

                g.CopyFromScreen(Point.Empty, Point.Empty, Screen.PrimaryScreen.WorkingArea.Size);

                pictureBox1.Image = b;

            }

        }

Making Keyboard Shortcuts

        private void textBox1_KeyDown(object sender, KeyEventArgs e)

        {

            if(e.Control && e.KeyCode.ToString() == "F")

                MessageBox.Show("You pressed ctrl and F from the textbox");

            if (e.Alt && e.KeyCode.ToString() == "F")

                MessageBox.Show("You pressed alt and F from the textbox");

            if (e.Shift && e.KeyCode.ToString() == "F")

                MessageBox.Show("You pressed Shift and F from the textbox");

        }