由于WebSocket允许保持长连接,因此当建立连接后服务器可以主动地向Client发送相关信息.下面通过服务端获取当前CPU的使用情况主动发送给网页,让网页实时显示CPU使用情况的曲线图.该事例的主要功能是包括服务端获取CPU使和情况和HTML5使用canvas进行曲线图绘制.

应用效果

实现效果主要是模仿windows的任务管理器,显示每个核的工作情况.

C#获取CPU使用情况

可能通过PerformanceCounter来获取具本CPU线程的使用情况,不过在构建PerformanceCounter前先获取到CPU对应的线程数量.获取这个数量可以通过Environment.ProcessorCount属性获取,然后遍历构建每个PerformanceCounter

int coreCount = Environment.ProcessorCount;        for (int i = 0; i < coreCount; i++){mCounters.Add(new PerformanceCounter("Processor", "% Processor Time", i.ToString()));}

为了方便计数器的处理,简单地封装了一个基础类,完整代码如下:

/// <summary>/// Copyright © henryfan 2012      ///Email:  henryfan@msn.com   ///HomePage:    http://www.ikende.com       ///CreateTime:  2012/12/24 15:10:44/// </summary>public class ProcessorCounter{private List<PerformanceCounter> mCounters = new List<PerformanceCounter>();public IList<PerformanceCounter> Counters{get{return mCounters;}}public void Open(){int coreCount = Environment.ProcessorCount;        for (int i = 0; i < coreCount; i++){mCounters.Add(new PerformanceCounter("Processor", "% Processor Time", i.ToString()));}}public ItemUsage[] GetValues(){ItemUsage[] values = new ItemUsage[mCounters.Count];for (int i = 0; i < mCounters.Count; i++){values[i] = new ItemUsage();values[i].ID = i.ToString();values[i].Name = "CPU " +i.ToString();values[i].Percent =  mCounters[i].NextValue();}return values;}}public class ItemUsage{public string Name { get; set; }public float Percent { get; set; }public  string ID { get; set; }}

这样一个用于统计CPU所有线程使用情况计数的类就完成了.

页面绘制处理

首先定义一些简单的处理结构

function ProcessorInfo() {this.Item = null;this.Points = new Array();for (var i = 0; i < 50; i++) {this.Points.push(new Point(0, 0));}}function Point(x, y) {this.X = x;this.Y = y;}

主要定义线程信息结构,默认初始化50个座标,当在接收服务线程使用情况的时候,构建一个点添加到数组件尾部同时把第一个移走.通过定时绘制这50个点的曲线这样一个动态的走势就可以完成了.

function drawProceessor(item) {var canvas = document.getElementById('processimg' + item.Item.ID);var context = canvas.getContext('2d');context.beginPath();context.rect(0, 0, 200, 110);context.fillStyle = 'black';context.fill();context.lineWidth = 2;context.strokeStyle = 'white';context.stroke();context.beginPath();context.moveTo(2, 106);for (var i = 0; i < item.Points.length; i++) {context.lineTo(4 * i + 2, 110 - item.Points[i].Y - 4);}context.lineTo(200, 106);context.closePath();context.lineWidth = 1;context.fillStyle = '#7FFF00';context.fill();context.strokeStyle = '#7CFC00';context.stroke();context.font = '12pt Calibri';context.fillStyle = 'white';context.fillText(item.Item.Name, 60, 20);}function addUploadItem(info) {if (cpus[info.ID] == null) {var pinfo = new ProcessorInfo();pinfo.Item = info;$('<canvas id="processimg' + info.ID + '" width="200" height="110"></canvas>').appendTo($('#lstProcessors'));cpus[info.ID] = pinfo;processors.push(pinfo);pinfo.Points.shift();pinfo.Points.push(new Point(0, info.Percent));drawProceessor(pinfo);} else {var pinfo = cpus[info.ID];pinfo.Points.shift();pinfo.Points.push(new Point(0, info.Percent));}}

只需要通过定时器来不停地更新线程使用绘制即可.

setInterval(function () {for (var i = 0; i < processors.length; i++) {drawProceessor(processors[i]);}}, 1000);

服务端

对于服务端其实可以根据自己的需要来使用websocket协议实现,.net 4.5也提供相应的封装.而这里则使用了beetle对应websocket的扩展协议包,整体代码如下:

class Program : WebSocketJsonServer{static void Main(string[] args){TcpUtils.Setup("beetle");Program server = new Program();server.Open(8070);Console.WriteLine("websocket start@8070");ProcessorCounter counters = new ProcessorCounter();counters.Open();while (true){ItemUsage[] items = counters.GetValues();foreach (ItemUsage item in items){Console.WriteLine("{0}:{1}%", item.Name, item.Percent);}JsonMessage message = new JsonMessage();message.type = "cpu useage";message.data = items;foreach (TcpChannel channel in server.Server.GetOnlines()){channel.Send(message);}System.Threading.Thread.Sleep(995);}System.Threading.Thread.Sleep(-1);}protected override void OnError(object sender, ChannelErrorEventArgs e){base.OnError(sender, e);Console.WriteLine(e.Exception.Message);}protected override void OnConnected(object sender, ChannelEventArgs e){base.OnConnected(sender, e);Console.WriteLine("{0} connected", e.Channel.EndPoint);}protected override void OnDisposed(object sender, ChannelDisposedEventArgs e){base.OnDisposed(sender, e);Console.WriteLine("{0} disposed", e.Channel.EndPoint);}}

每秒获取一次CPU的使用情况,并把信息以json的方式发送给当前所有在线的连接.

下载

完整代码:ProcessorsMonitor.rar (686.02 kb)

演示地址:http://html5.ikende.com/ProcessorsMonitor.htm (浏览器使用chrome或IE10)