C＃ - 獲取RawFraction性能計數器以顯示持久值

Question

我創建了一個性能計數器，它在基值（RawBase）上顯示增量值（RawFraction類型）的一小部分。

不幸的是，當監視這個值時，它只顯示其中一個計數器遞增時的百分比。在所有其他時間，它被採樣，它顯示0.有什麼方法告訴計數器保持最後一個值，直到下一次需要重新計算分數爲止？

Answer 1

很難知道自己錯在哪裏了，你沒有看到任何你的代碼，但這裏是它被使用的例子正確（來源：http://msdn.microsoft.com/en-us/library/system.diagnostics.performancecountertype.aspx）

using System; 
using System.Collections; 
using System.Collections.Specialized; 
using System.Diagnostics; 

public class App 
{ 
    private static PerformanceCounter PC; 
    private static PerformanceCounter BPC; 

    public static void Main() 
    { 
     ArrayList samplesList = new ArrayList(); 

     // If the category does not exist, create the category and exit. 
     // Performance counters should not be created and immediately used. 
     // There is a latency time to enable the counters, they should be created 
     // prior to executing the application that uses the counters. 
     // Execute this sample a second time to use the counters. 
     if (SetupCategory()) 
      return; 
     CreateCounters(); 
     CollectSamples(samplesList); 
     CalculateResults(samplesList); 
    } 

    private static bool SetupCategory() 
    { 
     if (!PerformanceCounterCategory.Exists("RawFractionSampleCategory")) 
     { 
      CounterCreationDataCollection CCDC = new CounterCreationDataCollection(); 

      // Add the counter. 
      CounterCreationData rf = new CounterCreationData(); 
      rf.CounterType = PerformanceCounterType.RawFraction; 
      rf.CounterName = "RawFractionSample"; 
      CCDC.Add(rf); 

      // Add the base counter. 
      CounterCreationData rfBase = new CounterCreationData(); 
      rfBase.CounterType = PerformanceCounterType.RawBase; 
      rfBase.CounterName = "RawFractionSampleBase"; 
      CCDC.Add(rfBase); 

      // Create the category. 
      PerformanceCounterCategory.Create("RawFractionSampleCategory", 
       "Demonstrates usage of the RawFraction performance counter type.", 
       PerformanceCounterCategoryType.SingleInstance, CCDC); 

      return (true); 
     } 
     else 
     { 
      Console.WriteLine("Category exists - RawFractionSampleCategory"); 
      return (false); 
     } 
    } 

    private static void CreateCounters() 
    { 
     // Create the counters. 
     PC = new PerformanceCounter("RawFractionSampleCategory", 
      "RawFractionSample", 
      false); 

     BPC = new PerformanceCounter("RawFractionSampleCategory", 
      "RawFractionSampleBase", 
      false); 

     PC.RawValue = 0; 
     BPC.RawValue = 0; 
    } 

    private static void CollectSamples(ArrayList samplesList) 
    { 
     Random r = new Random(DateTime.Now.Millisecond); 

     // Initialize the performance counter. 
     PC.NextSample(); 

     // Loop for the samples. 
     for (int j = 0; j < 100; j++) 
     { 
      int value = r.Next(1, 10); 
      Console.Write(j + " = " + value); 

      // Increment the base every time, because the counter measures the number 
      // of high hits (raw fraction value) against all the hits (base value). 
      BPC.Increment(); 

      // Get the % of samples that are 9 or 10 out of all the samples taken. 
      if (value >= 9) 
       PC.Increment(); 

      // Copy out the next value every ten times around the loop. 
      if ((j % 10) == 9) 
      { 
       Console.WriteLine(";  NextValue() = " + PC.NextValue().ToString()); 
       OutputSample(PC.NextSample()); 
       samplesList.Add(PC.NextSample()); 
      } 
      else 
       Console.WriteLine(); 

      System.Threading.Thread.Sleep(50); 
     } 
    } 

    private static void CalculateResults(ArrayList samplesList) 
    { 
     for (int i = 0; i < samplesList.Count; i++) 
     { 
      // Output the sample. 
      OutputSample((CounterSample)samplesList[i]); 

      // Use .NET to calculate the counter value. 
      Console.WriteLine(".NET computed counter value = " + 
       CounterSampleCalculator.ComputeCounterValue((CounterSample)samplesList[i])); 

      // Calculate the counter value manually. 
      Console.WriteLine("My computed counter value = " + 
       MyComputeCounterValue((CounterSample)samplesList[i])); 
     } 
    } 

    //++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    // Formula from MSDN - 
    //  Description - This counter type shows the ratio of a subset to its set as a percentage. 
    //   For example, it compares the number of bytes in use on a disk to the 
    //   total number of bytes on the disk. Counters of this type display the 
    //   current percentage only, not an average over time. 
    // 
    // Generic type - Instantaneous, Percentage 
    //  Formula - (N0/D0), where D represents a measured attribute and N represents one 
    //   component of that attribute. 
    // 
    //  Average - SUM (N/D) /x 
    //  Example - Paging File\% Usage Peak 
    //++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++//++++++++ 
    private static Single MyComputeCounterValue(CounterSample rfSample) 
    { 
     Single numerator = (Single)rfSample.RawValue; 
     Single denomenator = (Single)rfSample.BaseValue; 
     Single counterValue = (numerator/denomenator) * 100; 
     return (counterValue); 
    } 

    // Output information about the counter sample. 
    private static void OutputSample(CounterSample s) 
    { 
     Console.WriteLine("+++++++++++"); 
     Console.WriteLine("Sample values - \r\n"); 
     Console.WriteLine(" BaseValue  = " + s.BaseValue); 
     Console.WriteLine(" CounterFrequency = " + s.CounterFrequency); 
     Console.WriteLine(" CounterTimeStamp = " + s.CounterTimeStamp); 
     Console.WriteLine(" CounterType  = " + s.CounterType); 
     Console.WriteLine(" RawValue   = " + s.RawValue); 
     Console.WriteLine(" SystemFrequency = " + s.SystemFrequency); 
     Console.WriteLine(" TimeStamp  = " + s.TimeStamp); 
     Console.WriteLine(" TimeStamp100nSec = " + s.TimeStamp100nSec); 
     Console.WriteLine("++++++++++++++++++++++"); 
    } 
}