Initial data commit

Task/Draw-a-clock/C-sharp/draw-a-clock.cs

@@ -0,0 +1,87 @@
+using System;
+using System.Drawing;
+using System.Drawing.Drawing2D;
+using System.Windows.Forms;
+
+public class Clock : Form
+{
+    static readonly float degrees06 = (float)Math.PI / 30;
+    static readonly float degrees30 = degrees06 * 5;
+    static readonly float degrees90 = degrees30 * 3;
+
+    readonly int margin = 20;
+
+    private Point p0;
+
+    public Clock()
+    {
+        Size = new Size(500, 500);
+        StartPosition = FormStartPosition.CenterScreen;
+        Resize += (sender, args) => ResetSize();
+        ResetSize();
+        var timer = new Timer() { Interval = 1000, Enabled = true };
+        timer.Tick += (sender, e) => Refresh();
+        DoubleBuffered = true;
+    }
+
+    private void ResetSize()
+    {
+        p0 = new Point(ClientRectangle.Width / 2, ClientRectangle.Height / 2);
+        Refresh();
+    }
+
+    protected override void OnPaint(PaintEventArgs e)
+    {
+        base.OnPaint(e);
+        e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
+
+        drawFace(e.Graphics);
+
+        var time = DateTime.Now;
+        int second = time.Second;
+        int minute = time.Minute;
+        int hour = time.Hour;
+
+        float angle = degrees90 - (degrees06 * second);
+        DrawHand(e.Graphics, Pens.Red, angle, 0.95);
+
+        float minsecs = (minute + second / 60.0F);
+        angle = degrees90 - (degrees06 * minsecs);
+        DrawHand(e.Graphics, Pens.Black, angle, 0.9);
+
+        float hourmins = (hour + minsecs / 60.0F);
+        angle = degrees90 - (degrees30 * hourmins);
+        DrawHand(e.Graphics, Pens.Black, angle, 0.6);
+    }
+
+    private void drawFace(Graphics g)
+    {
+        int radius = Math.Min(p0.X, p0.Y) - margin;
+        g.FillEllipse(Brushes.White, p0.X - radius, p0.Y - radius, radius * 2, radius * 2);
+
+        for (int h = 0; h < 12; h++)
+            DrawHand(g, Pens.LightGray, h * degrees30, -0.05);
+
+        for (int m = 0; m < 60; m++)
+            DrawHand(g, Pens.LightGray, m * degrees06, -0.025);
+    }
+
+    private void DrawHand(Graphics g, Pen pen, float angle, double size)
+    {
+        int radius = Math.Min(p0.X, p0.Y) - margin;
+
+        int x0 = p0.X + (size > 0 ? 0 : Convert.ToInt32(radius * (1 + size) * Math.Cos(angle)));
+        int y0 = p0.Y + (size > 0 ? 0 : Convert.ToInt32(radius * (1 + size) * Math.Sin(-angle)));
+
+        int x1 = p0.X + Convert.ToInt32(radius * (size > 0 ? size : 1) * Math.Cos(angle));
+        int y1 = p0.Y + Convert.ToInt32(radius * (size > 0 ? size : 1) * Math.Sin(-angle));
+
+        g.DrawLine(pen, x0, y0, x1, y1);
+    }
+
+    [STAThread]
+    static void Main()
+    {
+        Application.Run(new Clock());
+    }
+}