/* Quote from
Programming .NET Windows Applications
By Jesse Liberty, Dan Hurwitz
First Edition October 2003
Pages: 1246 (More details)
*/
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Timers;
using System.Windows.Forms;
public class Form1 : System.Windows.Forms.Form
{
private System.ComponentModel.IContainer components;
private int FaceRadius = 450; // size of the clock face
private bool b24Hours = false; // 24 hour clock face?
private System.Windows.Forms.Button btnClockFormat;
private System.Windows.Forms.Timer timer1; // center of the clock
private DateTime currentTime; // used in more than one method
public Form1()
{
// Required for Windows Form Designer support
InitializeComponent();
// use the user's choice of colors
BackColor = SystemColors.Window;
ForeColor = SystemColors.WindowText;
timer1.Interval = 500;
timer1.Enabled = true;
}
protected override void OnPaint ( PaintEventArgs e )
{
Graphics g = e.Graphics;
SetScale(g);
DrawFace(g);
DrawTime(g,true); // force an update
}
#region Windows Form Designer generated code
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.components = new System.ComponentModel.Container();
this.btnClockFormat = new System.Windows.Forms.Button();
this.timer1 = new System.Windows.Forms.Timer(this.components);
this.SuspendLayout();
//
// btnClockFormat
//
this.btnClockFormat.Location = new System.Drawing.Point(8, 8);
this.btnClockFormat.Name = "btnClockFormat";
this.btnClockFormat.TabIndex = 1;
this.btnClockFormat.Text = "24 Hours";
this.btnClockFormat.Click += new System.EventHandler(this.btnClockFormat_Click);
//
// timer1
//
this.timer1.Tick += new System.EventHandler(this.timer1_Tick);
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.btnClockFormat});
this.Name = "Form1";
this.Text = "Clock2CS";
this.ResumeLayout(false);
}
#endregion
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
private void SetScale(Graphics g)
{
// if the form is too small, do nothing
if ( Width == 0 || Height == 0 )
return;
// set the origin at the center
g.TranslateTransform(Width/2, Height/2);
// set inches to the minimum of the width
// or height dividedby the dots per inch
float inches = Math.Min(Width / g.DpiX, Height / g.DpiX);
// set the scale to a grid of 2000 by 2000 units
g.ScaleTransform(
inches * g.DpiX / 2000, inches * g.DpiY / 2000);
}
private void DrawFace(Graphics g)
{
// numbers are in forecolor except flash number in green
// as the seconds go by.
Brush brush = new SolidBrush(ForeColor);
Font font = new Font("Arial", 40);
float x, y;
// new code
int numHours = b24Hours ? 24 : 12;
int deg = 360 / numHours;
// for each of the hours on the clock face
for (int i = 1; i <= numHours; i++)
{
// i = hour 30 degrees = offset per hour
// +90 to make 12 straight up
x = GetCos(i*deg + 90) * FaceRadius;
y = GetSin(i*deg + 90) * FaceRadius;
StringFormat format = new StringFormat();
format.Alignment = StringAlignment.Center;
format.LineAlignment = StringAlignment.Center;
g.DrawString(
i.ToString(), font, brush, -x, -y,format);
} // end for loop
} // end drawFace
private void DrawTime(Graphics g, bool forceDraw)
{
// length of the hands
float hourLength = FaceRadius * 0.5f;
float minuteLength = FaceRadius * 0.7f;
float secondLength = FaceRadius * 0.9f;
// set to back color to erase old hands first
Pen hourPen = new Pen(BackColor);
Pen minutePen = new Pen(BackColor);
Pen secondPen = new Pen(BackColor);
// set the arrow heads
hourPen.EndCap = LineCap.ArrowAnchor;
minutePen.EndCap = LineCap.ArrowAnchor;
// hour hand is thicker
hourPen.Width = 30;
minutePen.Width = 20;
// second hand
Brush secondBrush = new SolidBrush(BackColor);
const int EllipseSize = 50;
GraphicsState state; // to to protect and to serve
// 1 - delete the old time
// delete the old second hand
// figure out how far around to rotate to draw the second hand
// save the current state, rotate, draw and then restore the state
float rotation = GetSecondRotation();
state = g.Save();
g.RotateTransform(rotation);
g.FillEllipse(
secondBrush,
-(EllipseSize/2),
-secondLength,
EllipseSize,
EllipseSize);
g.Restore(state);
DateTime newTime = DateTime.Now;
bool newMin = false; // has the minute changed?
// if the minute has changed, set the flag
if ( newTime.Minute != currentTime.Minute )
newMin = true;
// if the minute has changed or you must draw anyway then you
// must first delete the old minute and hour hand
if ( newMin || forceDraw )
{
// figure out how far around to rotate to draw the minute hand
// save the current state, rotate, draw and then restore the state
rotation = GetMinuteRotation();
state = g.Save();
g.RotateTransform(rotation);
g.DrawLine(minutePen,0,0,0,-minuteLength);
g.Restore(state);
// figure out how far around to rotate to draw the hour hand
// save the current state, rotate, draw and then restore the state
rotation = GetHourRotation();
state = g.Save();
g.RotateTransform(rotation);
g.DrawLine(hourPen,0,0,0,-hourLength);
g.Restore(state);
}
// step 2 - draw the new time
currentTime = newTime;
hourPen.Color = Color.Red;
minutePen.Color = Color.Blue;
secondPen.Color = Color.Green;
secondBrush = new SolidBrush(Color.Green);
// draw the new second hand
// figure out how far around to rotate to draw the second hand
// save the current state, rotate, draw and then restore the state
state = g.Save();
rotation = GetSecondRotation();
g.RotateTransform(rotation);
g.FillEllipse(
secondBrush,
-(EllipseSize/2),
-secondLength,
EllipseSize,
EllipseSize);
g.Restore(state);
// if the minute has changed or you must draw anyway then you
// must draw the new minute and hour hand
if ( newMin || forceDraw )
{
// figure out how far around to rotate to draw the minute hand
// save the current state, rotate, draw and then restore the state
state = g.Save();
rotation = GetMinuteRotation();
g.RotateTransform(rotation);
g.DrawLine(minutePen,0,0,0,-minuteLength);
g.Restore(state);
// figure out how far around to rotate to draw the hour hand
// save the current state, rotate, draw and then restore the state
state = g.Save();
rotation = GetHourRotation();
g.RotateTransform(rotation);
g.DrawLine(hourPen,0,0,0,-hourLength);
g.Restore(state);
}
}
// determine the rotation to draw the hour hand
private float GetHourRotation()
{
// degrees depend on 24 vs. 12 hour clock
float deg = b24Hours ? 15 : 30;
float numHours = b24Hours ? 24 : 12;
return( 360f * currentTime.Hour / numHours +
deg * currentTime.Minute / 60f);
}
private float GetMinuteRotation()
{
return( 360f * currentTime.Minute / 60f );
}
private float GetSecondRotation()
{
return(360f * currentTime.Second / 60f);
}
private static float GetSin(float degAngle)
{
return (float) Math.Sin(Math.PI * degAngle / 180f);
}
private static float GetCos(float degAngle)
{
return (float) Math.Cos(Math.PI * degAngle / 180f);
}
private void btnClockFormat_Click(object sender, System.EventArgs e)
{
btnClockFormat.Text = b24Hours ? "24 Hour" : "12 Hour";
b24Hours = ! b24Hours;
this.Invalidate();
}
private void timer1_Tick(object sender, System.EventArgs e)
{
this.Invalidate();
}
}
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