如何使用NvAPI_DISP_GetDisplayConfig
How to use NvAPI_DISP_GetDisplayConfig?
使用 NVAPI 时,我在NvAPI_DISP_GetDisplayConfig时遇到问题。我在第二次调用NvAPI_DISP_GetDisplayConfig时收到AppCrash。似乎想不通为什么。
NvU32 count = 0;
status = NvAPI_DISP_GetDisplayConfig(&count, NULL);
if (status != NVAPI_OK)
PrintError(status);
printf("Configs: %in", count);
NV_DISPLAYCONFIG_PATH_INFO *configinfos = new NV_DISPLAYCONFIG_PATH_INFO[count];
configinfos[0].version = NV_DISPLAYCONFIG_PATH_INFO_VER;
status = NvAPI_DISP_GetDisplayConfig(&count, configinfos);
if (status != NVAPI_OK)
PrintError(status);
在我的系统上,第一次调用后计数 = 2。关于NvAPI_DISP_GetDisplayConfig的注释说:
NVAPI_INTERFACE NvAPI_DISP_GetDisplayConfig(
__inout NvU32 * 路径信息计数,
__out_ecount_full_opt *路径信息计数 NV_DISPLAYCONFIG_PATH_INFO * 路径信息
)说明:此 API 允许调用方检索当前全局显示
版本
配置。
用法:调用方可能必须调用三次才能获取所有必需
的内容 配置详细信息如下:
第一次传递:调用方应在设置
路径信息的情况下调用NvAPI_DISP_GetDisplayConfig() 到 NULL 以获取路径信息计数。
第二遍:根据
pathInfoCount(从第一遍)获取//!//!目标信息计数。如果
sourceModeInfo 需要分配内存,或者它可以初始化为 NULL。
第三遍(可选,仅当需要目标信息时才需要):分配
目标信息的内存与
目标信息计数(从第二遍)。支持的操作系统:Windows Vista 及更高
谢谢。
编辑:我也尝试设置configinfos[0].sourceModeInfo = NULL无济于事。我还尝试遍历数组以将所有 .version 和 .sourceModeInfo 设置为无济于事(我在文档中看到的一个例子只在数组中的第一项上设置了版本)
这应该适合您:
NvAPI_Status status = NVAPI_OK;
NvU32 deviceCount = 0;
NV_DISPLAYCONFIG_PATH_INFO_V2 * pathInfo = NULL;
status = NvAPI_Initialize();
if (status == NVAPI_OK) {
status = NvAPI_DISP_GetDisplayConfig(&deviceCount, pathInfo);
if ((status == NVAPI_OK) && (deviceCount > 0)) {
pathInfo = new NV_DISPLAYCONFIG_PATH_INFO_V2[deviceCount];
for (int i = 0; i < deviceCount; i++)
{
pathInfo[i].targetInfo = 0;
pathInfo[i].targetInfoCount = 0;
pathInfo[i].version = NV_DISPLAYCONFIG_PATH_INFO_VER2;
pathInfo[i].sourceModeInfo = 0;
pathInfo[i].reserved = 0;
}
status = NvAPI_DISP_GetDisplayConfig(&deviceCount, pathInfo);
if (status == NVAPI_OK) {
for (int i = 0; i < deviceCount; i++)
{
pathInfo[i].sourceModeInfo = new NV_DISPLAYCONFIG_SOURCE_MODE_INFO_V1;
pathInfo[i].sourceModeInfo->reserved = 0;
pathInfo[i].targetInfo = new NV_DISPLAYCONFIG_PATH_TARGET_INFO_V2[pathInfo[i].targetInfoCount];
for (int j = 0; j < pathInfo[i].targetInfoCount; j++) {
pathInfo[i].targetInfo[j].details = 0;
}
}
}
status = NvAPI_DISP_GetDisplayConfig(&deviceCount, pathInfo);
for (int i = 0; i < deviceCount; i++)
{
if (pathInfo[i].sourceModeInfo) delete pathInfo[i].sourceModeInfo;
if (pathInfo[i].targetInfo) delete [] pathInfo[i].targetInfo;
}
delete[] pathInfo;
}
}
马科斯的回答更彻底。我相信您的代码中的特定问题是您没有初始化第二个路径信息。因此,您需要添加:
configinfos[1].version = NV_DISPLAYCONFIG_PATH_INFO_VER;
这也是一种很好的形式,总是把你的记忆化。因此,在分配后,您应该立即执行以下操作:
memset(configinfos, 0, sizeof(NV_DISPLAYCONFIG_PATH_INFO) * count);
或者您可以单独设置这些值。
NvAPI 附带的示例代码中有一个名为 DisplayConfiguration 的示例,该示例完全利用了 GetDisplayConfig。从 DisplayConfiguration.cpp 复制粘贴函数:
NvAPI_Status AllocateAndGetDisplayConfig(NvU32* pathInfoCount, NV_DISPLAYCONFIG_PATH_INFO** pPathInfo)
{
NvAPI_Status ret;
// Retrieve the display path information
NvU32 pathCount = 0;
NV_DISPLAYCONFIG_PATH_INFO *pathInfo = NULL;
ret = NvAPI_DISP_GetDisplayConfig(&pathCount, NULL);
if (ret != NVAPI_OK) return ret;
pathInfo = (NV_DISPLAYCONFIG_PATH_INFO*) malloc(pathCount * sizeof(NV_DISPLAYCONFIG_PATH_INFO));
if (!pathInfo)
{
return NVAPI_OUT_OF_MEMORY;
}
memset(pathInfo, 0, pathCount * sizeof(NV_DISPLAYCONFIG_PATH_INFO));
for (NvU32 i = 0; i < pathCount; i++)
{
pathInfo[i].version = NV_DISPLAYCONFIG_PATH_INFO_VER;
}
// Retrieve the targetInfo counts
ret = NvAPI_DISP_GetDisplayConfig(&pathCount, pathInfo);
if (ret != NVAPI_OK)
{
return ret;
}
for (NvU32 i = 0; i < pathCount; i++)
{
// Allocate the source mode info
pathInfo[i].sourceModeInfo = (NV_DISPLAYCONFIG_SOURCE_MODE_INFO*) malloc(sizeof(NV_DISPLAYCONFIG_SOURCE_MODE_INFO));
if (pathInfo[i].sourceModeInfo == NULL)
{
return NVAPI_OUT_OF_MEMORY;
}
memset(pathInfo[i].sourceModeInfo, 0, sizeof(NV_DISPLAYCONFIG_SOURCE_MODE_INFO));
// Allocate the target array
pathInfo[i].targetInfo = (NV_DISPLAYCONFIG_PATH_TARGET_INFO*) malloc(pathInfo[i].targetInfoCount * sizeof(NV_DISPLAYCONFIG_PATH_TARGET_INFO));
if (pathInfo[i].targetInfo == NULL)
{
return NVAPI_OUT_OF_MEMORY;
}
// Allocate the target details
memset(pathInfo[i].targetInfo, 0, pathInfo[i].targetInfoCount * sizeof(NV_DISPLAYCONFIG_PATH_TARGET_INFO));
for (NvU32 j = 0 ; j < pathInfo[i].targetInfoCount ; j++)
{
pathInfo[i].targetInfo[j].details = (NV_DISPLAYCONFIG_PATH_ADVANCED_TARGET_INFO*) malloc(sizeof(NV_DISPLAYCONFIG_PATH_ADVANCED_TARGET_INFO));
memset(pathInfo[i].targetInfo[j].details, 0, sizeof(NV_DISPLAYCONFIG_PATH_ADVANCED_TARGET_INFO));
pathInfo[i].targetInfo[j].details->version = NV_DISPLAYCONFIG_PATH_ADVANCED_TARGET_INFO_VER;
}
}
// Retrieve the full path info
ret = NvAPI_DISP_GetDisplayConfig(&pathCount, pathInfo);
if (ret != NVAPI_OK)
{
return ret;
}
*pathInfoCount = pathCount;
*pPathInfo = pathInfo;
return NVAPI_OK;
}
现在,此功能可以像以下一样轻松地使用:
NV_DISPLAYCONFIG_PATH_INFO *pathInfo = NULL;
NvU32 pathCount = 0;
_allocateAndGetDisplayConfig(&pathCount, &pathInfo);
// Do whatever you need with the queried display data here
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