#include <iostream>#include <pdh.h>#pragma comment(lib, "pdh.lib")int main(){ PDH_STATUS status; HQUERY hQuery; HCOUNTER hCounter; PDH_FMT_COUNTERVALUE counterValue; // 打开查询 status = PdhOpenQuery(NULL, 0, &hQuery); if (status != ERROR_SUCCESS) { std::cout << "打开查询失败：" << status << std::endl; return 1; } // 添加计数器 status = PdhAddCounter(hQuery, L"\PhysicalDisk(_Total)\Disk Read Bytes/sec", 0, &hCounter); if (status != ERROR_SUCCESS) { std::cout << "添加计数器失败：" << status << std::endl; PdhCloseQuery(hQuery); return 1; } // 查询计数器值 status = PdhCollectQueryData(hQuery); if (status != ERROR_SUCCESS) { std::cout << "查询计数器值失败：" << status << std::endl; PdhCloseQuery(hQuery); return 1; } // 获取计数器值 status = PdhGetFormattedCounterValue(hCounter, PDH_FMT_LARGE, NULL, &counterValue); if (status != ERROR_SUCCESS) { std::cout << "获取计数器值失败：" << status << std::endl; PdhCloseQuery(hQuery); return 1; } // 输出计数器值 std::cout << "磁盘读速度：" << counterValue.largeValue << " 字节/秒" << std::endl; // 关闭查询 PdhCloseQuery(hQuery); return 0;}优化以上代码,这里会获取计数器值失败

您的代码存在两个问题：

1. 添加计数器时，计数器路径字符串中的反斜杠应该使用双反斜杠进行转义。

2. 获取计数器值时，应该先获取计数器值的大小，然后根据大小动态分配内存，最后再获取计数器值。这是因为 PDH_FMT_LARGE 格式的计数器值可能会非常大，超出常规的栈内存大小。

优化后的代码如下：

#include <iostream>
#include <pdh.h>

#pragma comment(lib, "pdh.lib")

int main()
{
    PDH_STATUS status;
    HQUERY hQuery;
    HCOUNTER hCounter;
    PDH_FMT_COUNTERVALUE buffer;
    DWORD bufferSize = sizeof(buffer);

    // 打开查询
    status = PdhOpenQuery(NULL, 0, &hQuery);
    if (status != ERROR_SUCCESS) {
        std::cout << "打开查询失败：" << status << std::endl;
        return 1;
    }

    // 添加计数器
    status = PdhAddCounter(hQuery, L"\\PhysicalDisk(_Total)\\Disk Read Bytes/sec", 0, &hCounter);
    if (status != ERROR_SUCCESS) {
        std::cout << "添加计数器失败：" << status << std::endl;
        PdhCloseQuery(hQuery);
        return 1;
    }

    // 查询计数器值
    status = PdhCollectQueryData(hQuery);
    if (status != ERROR_SUCCESS) {
        std::cout << "查询计数器值失败：" << status << std::endl;
        PdhCloseQuery(hQuery);
        return 1;
    }

    // 获取计数器值
    status = PdhGetFormattedCounterValue(hCounter, PDH_FMT_LARGE, NULL, &bufferSize);
    if (status != ERROR_SUCCESS) {
        std::cout << "获取计数器值大小失败：" << status << std::endl;
        PdhCloseQuery(hQuery);
        return 1;
    }

    BYTE* buffer = new BYTE[bufferSize];
    status = PdhGetFormattedCounterValue(hCounter, PDH_FMT_LARGE, NULL, &buffer);
    if (status != ERROR_SUCCESS) {
        std::cout << "获取计数器值失败：" << status << std::endl;
        delete[] buffer;
        PdhCloseQuery(hQuery);
        return 1;
    }

    // 输出计数器值
    std::cout << "磁盘读速度：" << ((PDH_FMT_LARGE*)buffer)->largeValue << " 字节/秒" << std::endl;

    // 释放内存
    delete[] buffer;

    // 关闭查询
    PdhCloseQuery(hQuery);

    return 0;
}

这里使用动态内存分配来存储计数器值，避免了栈内存溢出的问题。同时，在获取计数器值前先获取计数器值的大小，保证能够正确地存储计数器值。