C# 利用性能計數器監控網絡狀態

本例是利用C#中的性能計數器（PerformanceCounter）監控網絡的狀態，並能夠直觀的展現出來。本文僅供學習分享使用，如有不足之處，還請指正。

涉及知識點：

• PerformanceCounter，表示 Windows NT 性能計數器組件。NextValue() 即獲取計數器樣本並為其返回計算所得值。
• PerformanceCounterCategory 表示性能對象，它定義性能計數器的類別。通過這兩個即可得到計數器的信息。
• Chart 圖表，VS自帶的Chart圖表，大大簡化了對圖表的開發。關於Chart，此前已有例子說明
• Queue 隊列表示對象的先進先出集合。關於Queue此前已有例子說明
• TreeView 顯示標記項的分層集合，每個標記項用一個 System.Windows.Forms.TreeNode 來表示。即VS自帶的樹狀菜單
• Timer 實現按用戶定義的時間間隔引發事件的計時器。此計時器最宜用於 Windows 窗體應用程序中，並且必須在窗口中使用。定時刷新計數器中的值。

效果圖

如下圖所示：

關於可用的計數器列表【計數器有很多，一級菜單是計數器的類別，二級菜單是計數器InstanceName,三級菜單是計數器名稱】，如下圖所示：

核心代碼

代碼如下：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Windows.Forms.DataVisualization.Charting;
using System.Diagnostics;

namespace DemoSharp
{
    public partial class NetworkMonitor : Form
    {
        private PerformanceCounter mCounter;//當前計數器

        private Queue<double> dataQueue = new Queue<double>(100);//初始化隊列

        public NetworkMonitor()
        {
            InitializeComponent();
            InitCounterCategory();
            InitChart();
        }

        /// <summary>
        /// 初始化計數器信息
        /// </summary>
        private void InitCounterCategory() {
            //獲取所有的計數器類別
            var counterCategories = PerformanceCounterCategory.GetCategories().OrderBy(p=>p.CategoryName);
            int i=0;
            foreach (var counterCategory in counterCategories) {
                //屬於線程級別的不顯示
                if (counterCategory.CategoryName == "Thread") {
                    continue;
                }
                //將信息綁定的TreeView上
                this.tvCategory.CheckBoxes = true;
                this.tvCategory.Nodes.Add(counterCategory.CategoryName);
                string[] instanceNames = counterCategory.GetInstanceNames();
                int j = 0;
                foreach (var instanceName in instanceNames) {
                    this.tvCategory.Nodes[i].Nodes.Add(instanceName);
                    var counters = counterCategory.GetCounters(instanceName).Select(p=>string.Format("{0}",p.CounterName));
                    int k = 0;
                    foreach (var counter in counters) {
                        this.tvCategory.Nodes[i].Nodes[j].Nodes.Add(counter);
                        k++;
                    }
                    j++;
                }
                i++;
            }
            //初始化Counter
            PerformanceCounterCategory pcCategory = new PerformanceCounterCategory("Network Interface");
            string[] iNames = pcCategory.GetInstanceNames();
            PerformanceCounter[] pCounters = pcCategory.GetCounters(iNames[0]);
            //給網絡監控計數器賦值
            mCounter = pCounters[0];
            mCounter.NextValue();//初始值
        }

         //<summary>
         //初始化圖表
         //</summary>
        private void InitChart()
        {
            //定義圖表區域
            this.chart1.ChartAreas.Clear();
            ChartArea chartArea1 = new ChartArea("C1");
            this.chart1.ChartAreas.Add(chartArea1);
            //定義存儲和顯示點的容器
            this.chart1.Series.Clear();
            Series series1 = new Series("S1");
            series1.ChartArea = "C1";
            this.chart1.Series.Add(series1);
            //設置圖表顯示樣式
            this.chart1.ChartAreas[0].AxisY.ArrowStyle = AxisArrowStyle.SharpTriangle;
            this.chart1.ChartAreas[0].AxisY.Title = "Kkbps";//坐標軸的標題
            this.chart1.ChartAreas[0].AxisY.TextOrientation = TextOrientation.Rotated270;
            this.chart1.ChartAreas[0].AxisY.Minimum = 0;
            this.chart1.ChartAreas[0].AxisY.Maximum = 50;
            this.chart1.ChartAreas[0].AxisY.Interval = 5;
            this.chart1.ChartAreas[0].AxisX.Interval = 5;
            this.chart1.ChartAreas[0].AxisX.ArrowStyle = AxisArrowStyle.SharpTriangle;
            this.chart1.ChartAreas[0].AxisX.Title = "Sec";
            this.chart1.ChartAreas[0].AxisX.TextOrientation = TextOrientation.Horizontal;
            this.chart1.ChartAreas[0].AxisX.MajorGrid.LineColor = System.Drawing.Color.Silver;
            this.chart1.ChartAreas[0].AxisY.MajorGrid.LineColor = System.Drawing.Color.Silver;
            //設置標題
            this.chart1.Titles.Clear();
            this.chart1.Titles.Add("S01");
            this.chart1.Titles[0].Text = "XXX網絡監控顯示";
            this.chart1.Titles[0].ForeColor = Color.RoyalBlue;
            this.chart1.Titles[0].Font = new System.Drawing.Font("Microsoft Sans Serif", 12F);
            //設置圖表顯示樣式
            this.chart1.Series[0].Color = Color.LightGreen;
            this.chart1.Series[0].ChartType = SeriesChartType.Area;//圖表形狀
            this.chart1.Series[0].Points.Clear();
        }

        /// <summary>
        /// 啟動定時器
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnStart_Click(object sender, EventArgs e)
        {
            this.timer1.Start();
            
        }

        /// <summary>
        /// 停止定時器
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnStop_Click(object sender, EventArgs e)
        {
            this.timer1.Stop();
        }

        /// <summary>
        /// 定時執行函數
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void timer1_Tick(object sender, EventArgs e)
        {
            UpdateQueueValue();
            this.chart1.Series[0].Points.Clear();
            if (dataQueue.Max() > this.chart1.ChartAreas[0].AxisY.Maximum) {
                this.chart1.ChartAreas[0].AxisY.Maximum = Math.Ceiling(dataQueue.Max() / 10) * 10;
                this.chart1.ChartAreas[0].AxisY.Interval = this.chart1.ChartAreas[0].AxisY.Maximum / 10;
            }
            for (int i = 0; i < dataQueue.Count; i++)
            {
                this.chart1.Series[0].Points.AddXY((i + 1), dataQueue.ElementAt(i));
            }
        }

         //更新隊列中的值
        private void UpdateQueueValue()
        {

            if (dataQueue.Count > 100)
            {
                dataQueue.Dequeue();
            }
            //獲取的值就Byte/s 所以要除以1024
            dataQueue.Enqueue(mCounter.NextValue() / (1024));

        }

        /// <summary>
        /// 當選中復選框時發生
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void tvCategory_AfterCheck(object sender, TreeViewEventArgs e)
        {
            bool flag = e.Node.Checked;//取得選中狀態，所有子節點的狀態保持一致
            CheckedStated(e.Node.Nodes, flag);
        }

        /// <summary>
        /// 采用遞歸方法修改節點的選中狀態
        /// </summary>
        /// <param name="nodes"></param>
        /// <param name="flag"></param>
        private void CheckedStated(TreeNodeCollection nodes,bool flag) {
            
            if (nodes != null)
            {
                foreach (TreeNode node in nodes)
                {
                    node.Checked = flag;
                    CheckedStated(node.Nodes, flag);
                }
            }
        }
    }
}

備注：

性能計數器類別獲取出現異常的解決方案：

在CMD命令窗口中，執行 LODCTR /R 重置性能計數器。如下圖所示：

如果依然不行，嘗試以管理員身份運行【勾上】，如下圖所示：

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