PerformanceCounterCategory[] catalogs = PerformanceCounterCategory.GetCategories(); 

        PerformanceCounterCategory category = new PerformanceCounterCategory(categoryName);

        string[] instances = category.GetInstanceNames();
        PerformanceCounter[] counters = null;

        //判断是否有实例
        if (instances != null &&
            instances.Length > 0)
        {
            SortedList list = new SortedList();
            foreach (string ins in instances)
            {
                list.Add(ins, ins);
            }

            this.lbInstance.DataSource = list;
            this.lbInstance.DataBind();
            this.lbInstance.SelectedIndex = 0;

            counters = category.GetCounters(instances[0]);
        }
        else
        {
            counters = category.GetCounters();
        }

        SortedList listCounter = new SortedList();
        foreach (PerformanceCounter c in counters)
        {
            listCounter.Add(c.CounterName, c.CounterName);
        }

    [Serializable]
    private class CounterInfo
    {
        public string CategoryName;
        public string CounterName;
        public string InstanceNames;

        public CounterInfo(string categoryName, string counterName, string instanceNames)
        {
            CategoryName = categoryName;
            CounterName = counterName;
            InstanceNames = instanceNames;
        }
    }

        SortedList<string, CounterInfo> list = this.Counters;

        string strInstance = "";
        if (this.lbInstance.Items.Count > 0)
        {
            bool bFlag = true;
            foreach (ListItem item in this.lbInstance.Items)
            {
                if (item.Selected)
                {
                    if (bFlag)
                    {
                        strInstance = item.Value;
                        bFlag = false;
                    }
                    else
                    {
                        strInstance += "," + item.Value;
                    }
                }
            }
        }


        foreach(ListItem item in this.lbCounter.Items)
        {
            if (item.Selected)
            {
                list[this.ddlCategory.SelectedValue + " " + item.Value + " " + strInstance] = new CounterInfo(this.ddlCategory.SelectedValue,item.Value,strInstance);
            }
        }

        //这里不能使用ViewState
        Dictionary<string, PointPairList> dic = Cache["datasource"] as Dictionary<string,PointPairList>;
        if (dic == null)
        {
            dic = new Dictionary<string, PointPairList>();
        }

        ArrayList labels = new ArrayList();
        foreach (CounterInfo ci in this.Counters.Values)
        {
            PerformanceCounter counter = null;

            if (string.IsNullOrEmpty(ci.InstanceNames))
            {
                PointPairList list = null;
                dic.TryGetValue(ci.CategoryName + " " + ci.CounterName, out list);

                if (list == null)
                {
                    list = new PointPairList();
                }

                counter = new PerformanceCounter(ci.CategoryName, ci.CounterName);

                list.Add(list.Count + 1, counter.NextValue());

                dic[ci.CategoryName + " " + ci.CounterName] = list;

                labels.Add(ci.CategoryName + " " + ci.CounterName);
            }
            else
            {
                foreach (string ins in ci.InstanceNames.Split(','))
                {
                    PointPairList list = null;
                    if (!dic.TryGetValue(ci.CategoryName + " " + ci.CounterName + " " + ins,out list))
                    {
                        list = new PointPairList();
                    }

                    counter = new PerformanceCounter(ci.CategoryName, ci.CounterName,ins);

                    list.Add(list.Count + 1, counter.NextValue());

                    dic[ci.CategoryName + " " + ci.CounterName + " " + ins] = list;
                    labels.Add(ci.CategoryName + " " + ci.CounterName + " " + ins);
                }
            }
        }

        //生成随机颜色
        Random random = new Random(128);
        for (int i = 0; i < labels.Count; i++)
        {
            pane[0].AddCurve(labels[i] as string, dic[labels[i] as string], Color.FromArgb(random.Next(0, 255), random.Next(0, 255), random.Next(0, 255)));
        }

        pane.AxisChange(g);

        Cache["datasource"] = dic;