HreoWinGauge2.0组件集应用示例----时钟(2)

 

HreoWinGauge2.0 试用版下载地址：http://download.youkuaiyun.com/source/6896899

 

（5）使时间指针转动

时、分、秒指针指向的刻度必须与操作系统的时间相对应，且每秒钟更新一次。因此必须使用定时器进行定时刷新。可以使用C#.NET中任意一种定时器，这里使用System.Threading.Timer，请注意它的回调函数在另一个线程中执行，编写程序时应注意数据资源访问冲突和线程重入问题。详细程序如下：

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Threading;

 

namespace HeroWinGaugeSamples

{

    publicpartial class Clock : Form

    {

        private System.Threading.Timer timer;

        private HeroWinGauge.CircularPointer hourPointer, minutePointer, secondPointer;

 

        // This delegate enables asynchronous calls for setting

        // the text property on a TextBox control.

        delegatevoid SetClockCallback();

 

 

        public Clock()

        {

            InitializeComponent();

        }

 

        privatevoid Clock_Load(object sender,EventArgs e)

        {

            // Create the delegate that invokes methods for the timer.

            TimerCallback timerDelegate = new TimerCallback(ThreadProc);

 

            // Create a timer that signals the delegate to invoke

            // and start timer at once

            // null : no parameter send to callback function

            timer = new System.Threading.Timer(timerDelegate, null, 0, 1000);

            hourPointer = (HeroWinGauge.CircularPointer)gaugeContainer1.GaugeComponents[0].MiddleLayerParts[0];

            minutePointer = (HeroWinGauge.CircularPointer)gaugeContainer1.GaugeComponents[0].MiddleLayerParts[1];

            secondPointer = (HeroWinGauge.CircularPointer)gaugeContainer1.GaugeComponents[0].MiddleLayerParts[2];

 

        }

 

        // Thread for process data

        privatevoid ThreadProc(object patameter)           // the parameter is null

        {

            try

            {

                // because this function is running in an other thread,and may be called from two thread at the same time

                SetClockCallback d = new SetClockCallback(UpdateClock);

                //this.Invoke(d, new object[] { text });

                this.Invoke(d, null);

 

            }

            catch

            {

                return;

            }

           

        }

 

        // show the data

        privatevoid UpdateClock()

        {

            DateTime dt = DateTime.Now;

 

            //set label

            string text = dt.ToString("T");

            lbDateTime.Text = text;

 

            //set clock control

            if(dt.Hour>12)

                hourPointer.Value=dt.Hour-12 + (double)dt.Minute / 60;

            else

                hourPointer.Value = dt.Hour + (double)dt.Minute / 60;

           

            minutePointer.Value = dt.Minute + (double)dt.Second / 60;

            secondPointer.Value = dt.Second;

 

 

        }

 

 

        privatevoid Clock_FormClosing(object sender,FormClosingEventArgs e)

        {

                timer.Dispose();

 

        }

 

}

}

 

 

为了与系统时间对照比较，程序中还特别将系统时间显示在一个Label控件中。另外对时、分、秒指针的快速引用方法请参考使用手册中关于“在用户应用程序中如何快速引用对象和属性”一节的说明。

 

（6）编译运行程序

       到此，一个完整的时钟演示程序已全部完成，可以编译运行。运行此程序时，时、分、秒指针将按系统时间转动，完整界面见下图。

 

图7.6- 7 Clock窗体4