使用Windows监视器configurationfunction时发生I2C错误

我试图通过Windows API获取/设置显示器的亮度级别。 我已经尝试了低级监视器configuration函数和高级监视器configuration函数 ，但它们似乎都在同一个地方。 在这两种情况下，获取HMONITOR句柄并从HMONITOR获取物理监视器句柄都没有问题，但是一旦我尝试查询DDC / CIfunction，就会出现一个错误消息，提示“ An error occurred while transmitting data to the device on the I2C bus.

导致此错误的特定函数是高级函数的GetMonitorCapabilities和低级函数的GetCapabilitiesStringLength 。 他们都造成相同的错误。

这使我相信，也许我的显示器不支持DDC / CI，但我知道我的笔记本电脑的显示器亮度可以通过控制面板进行更改，所以它必须通过软件以某种方式控制。 另外，我可以在PowerShell脚本中成功使用WMI类来获取/设置本页所述的亮度。 我读过的大部分内容都表明，大多数现代笔记本电脑屏幕都支持DDC / CI。

有什么办法找出是什么原因导致这个错误或获得更多的信息呢？ 我目前正在Windows 7的Visual Studio 2013中使用C ++。如果我无法得到这个当前的方法，我可能会在我的C ++程序中使用WMI，但是我想我会先问一下。

这是我现在的代码：

 #include "stdafx.h" #include <windows.h> #include <highlevelmonitorconfigurationapi.h> #include <lowlevelmonitorconfigurationapi.h> #include <physicalmonitorenumerationapi.h> #include <iostream> #include <string> int _tmain(int argc, _TCHAR* argv[]) { DWORD minBrightness, curBrightness, maxBrightness; HWND curWin = GetConsoleWindow(); if (curWin == NULL) { std::cout << "Problem getting a handle to the window." << std::endl; return 1; } // Call MonitorFromWindow to get the HMONITOR handle HMONITOR curMon = MonitorFromWindow(curWin, MONITOR_DEFAULTTONULL); if (curMon == NULL) { std::cout << "Problem getting the display monitor" << std::endl; return 1; } // Call GetNumberOfPhysicalMonitorsFromHMONITOR to get the needed array size DWORD monitorCount; if (!GetNumberOfPhysicalMonitorsFromHMONITOR(curMon, &monitorCount)) { std::cout << "Problem getting the number of physical monitors" << std::endl; return 1; } // Call GetPhysicalMonitorsFromHMONITOR to get a handle to the physical monitor LPPHYSICAL_MONITOR physicalMonitors = (LPPHYSICAL_MONITOR)malloc(monitorCount*sizeof(PHYSICAL_MONITOR)); if (physicalMonitors == NULL) { std::cout << "Unable to malloc the physical monitor array." << std::endl; return 1; } if (!GetPhysicalMonitorsFromHMONITOR(curMon, monitorCount, physicalMonitors)) { std::cout << "Problem getting the physical monitors." << std::endl; return 1; } std::cout << "Num Monitors: " << monitorCount << std::endl; // This prints '1' as expected. wprintf(L"%s\n", physicalMonitors[0].szPhysicalMonitorDescription); // This prints "Generic PnP Monitor" as expected // Call GetMonitorCapabilities to find out which functions it supports DWORD monCaps; DWORD monColorTemps; // The following function call fails with the error "An error occurred while transmitting data to the device on the I2C bus." if (!GetMonitorCapabilities(physicalMonitors[0].hPhysicalMonitor, &monCaps, &monColorTemps)) { std::cout << "Problem getting the monitor's capabilities." << std::endl; DWORD errNum = GetLastError(); DWORD flags = FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS; LPVOID buffer; FormatMessage(flags, NULL, errNum, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPWSTR)&buffer, 0, NULL); wprintf(L"%s\n", buffer); return 1; } // Same error when I use GetCapabilitiesStringLength(...) here. // More code that is currently never reached... return 0; } 

编辑：另外我应该注意，即使监视器计数和文本描述是有效的，并且GetPhysicalMonitorsFromHMONITOR函数成功返回， physicalMonitors[0].hPhysicalMonitor为0。 任何想法，为什么这可能是？