使用 PerformanceCounters 时出现 InvalidOperationException

Question

获得：

Exception thrown: 'System.InvalidOperationException' in System.dll

附加信息：

Category does not exist.

代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication8
{
public partial class Form1 : Form
{
    PerformanceCounter cpuCounter;
    PerformanceCounter ramCounter;
    public Form1()
    {
        InitializeComponent();
    }
    int timeX = 0;
    private void timer1_Tick(object sender, EventArgs e)
    {
        cpuCounter = new PerformanceCounter();
        cpuCounter.CategoryName = "Processor";
        cpuCounter.CounterName = "% Processor Time";
        cpuCounter.InstanceName = "_Total";


        float cpuUsage = 0.00F;
        cpuCounter.NextValue();
        cpuUsage = cpuCounter.NextValue();
        textBox1.Text = cpuUsage.ToString();


        ramCounter = new PerformanceCounter("Memory", "Available MBytes");
        float ram = ramCounter.NextValue();
        textBox2.Text = ram.ToString();

        chart1.Series["CPU Usage"].Points.AddXY(timeX, (int)cpuUsage);
        chart2.Series["Memory Use"].Points.AddXY(timeX, (int)ram);

    }

    private void button1_Click(object sender, EventArgs e)
    {
       timer1.Start();
    }

    private void button2_Click(object sender, EventArgs e)
    {
        timer1.Stop();
    }
}
}

在每个 .nextValue();

上出现错误

我试过在 CategoryName 中添加 Processor Information，但也无济于事。

编辑： @Jim 这是我进行更改后的代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Diagnostics;
namespace WindowsFormsApplication12
{
public partial class Form1 : Form
{
    PerformanceCounter cpuCounter;
    PerformanceCounter ramCounter;

    public Form1()
    {
        InitializeComponent();

        InitializeCounters();
    }

    private void InitializeCounters()
    {
        cpuCounter = new PerformanceCounter();
        cpuCounter.CategoryName = "Processor";
        cpuCounter.CounterName = "% Processor Time";
        cpuCounter.InstanceName = "_Total";

       // ramCounter = new PerformanceCounter("Memory", "Available MBytes");
    }

    int timeX = 0;
    private void timer1_Tick(object sender, EventArgs e)
    {
        float cpuUsage = 0.00F;
        cpuUsage = cpuCounter.NextValue();
        textBox1.Text = cpuUsage.ToString();

        float ram = ramCounter.NextValue();
        textBox2.Text = ram.ToString();

        // Your chart stuff
        //chart1.Series["CPU Usage"].Points.AddXY(timeX, (int)cpuUsage);
        //chart2.Series["Memory Use"].Points.AddXY(timeX, (int)ram);
    }

    private void button1_Click(object sender, EventArgs e)
    {
        timer1.Start();
    }

    private void button2_Click(object sender, EventArgs e)
    {
        timer1.Stop();
    }
}

}

Answer 1

在使用 PerformanceCounter 之前创建一个类别。 msdn

中的更多详细信息和示例

    const String categoryName = "Processor";
    const String counterName = "% Processor Time";

    if ( !PerformanceCounterCategory.Exists(categoryName) ) 
    {

        CounterCreationDataCollection CCDC = new CounterCreationDataCollection();

        // Add the counter.
        CounterCreationData ETimeData = new CounterCreationData();
        ETimeData.CounterType = PerformanceCounterType.ElapsedTime;
        ETimeData.CounterName = counterName;
        CCDC.Add(ETimeData);       

        // Create the category.
        PerformanceCounterCategory.Create(categoryName,
                "Demonstrates ElapsedTime performance counter usage.",
            PerformanceCounterCategoryType.SingleInstance, CCDC);
    }

Answer 2

每次计时器滴答时您都在创建新的性能计数器，您只需要初始化 计数器一次。

Form1 代码隐藏

PerformanceCounter cpuCounter;   
PerformanceCounter ramCounter;

public Form1()
{
    InitializeComponent();

    InitializeCounters();
}

private void InitializeCounters()
{
    cpuCounter = new PerformanceCounter();
    cpuCounter.CategoryName = "Processor";
    cpuCounter.CounterName = "% Processor Time";
    cpuCounter.InstanceName = "_Total";

    ramCounter = new PerformanceCounter("Memory", "Available MBytes");
}

int timeX = 0;
private void timer1_Tick(object sender, EventArgs e)
{        
    float cpuUsage = 0.00F;
    cpuUsage = cpuCounter.NextValue();
    textBox1.Text = cpuUsage.ToString();
   
    float ram = ramCounter.NextValue();
    textBox2.Text = ram.ToString();

    // Your chart stuff
    //chart1.Series["CPU Usage"].Points.AddXY(timeX, (int)cpuUsage);
    //chart2.Series["Memory Use"].Points.AddXY(timeX, (int)ram);
}

private void button1_Click(object sender, EventArgs e)
{
    timer1.Start();
}

private void button2_Click(object sender, EventArgs e)
{
    timer1.Stop();
}

旁注：

还有 Dispose 不再使用时的计数器。也许在表单关闭事件中。

cpuCounter.Dispose();
ramCounter.Dispose();

结果

错误案例

如果我的示例仍然出现错误，这很可能是因为您系统上的一个或多个性能计数器已损坏。

重建所有性能计数器：

打开命令提示符（具有管理员权限）
运行命令：lodctr /R

留言：

Info: Successfully rebuilt performance counter setting ...

成功后会出现

如果您收到消息：

Unable to rebuild performance counter setting from system backup store, error code is 2

可能的解决方案：

关闭所有运行程序
确保使用大写 lodctr /R R
如果在目录 system32 中移动到目录 SysWOW64（使用 cd.. > cd syswow64）并在此目录中重试 lodctr /R 命令

使用 PerformanceCounters 时出现 InvalidOperationException

Getting InvalidOperationException when using PerformanceCounters

c#

performancecounter

Form1 代码隐藏

结果

错误案例