我有一个用C++编写的OpenGL库，使用C++/CLI适配器从C#应用程序中调用。我的问题是，如果在使用了Nvidia Optimus技术的笔记本电脑上使用该应用程序，应用程序将无法使用硬件加速并失败。
我已经尝试使用Nvidia文档中提供的信息http://developer.download.nvidia.com/devzone/devcenter/gamegraphics/files/OptimusRenderingPolicies.pdf，尝试将链接库用于我的C++-dll，并从我的OpenGL库中导出NvOptimusEnablement，但这失败了。 我想我必须对.exe文件而不是与.exe链接的.dll文件进行一些操作。
对我们来说，使用配置文件并不是一个好选择，因为我们需要确保使用了NVIDIA硬件。
是否有办法让C#应用程序强制使用Nvidia芯片组而不是集成的Intel芯片组？
[System.Runtime.InteropServices.DllImport("nvapi64.dll", EntryPoint = "fake")]
static extern int LoadNvApi64();
[System.Runtime.InteropServices.DllImport("nvapi.dll", EntryPoint = "fake")]
static extern int LoadNvApi32();
private void InitializeDedicatedGraphics()
{
try
{
if (Environment.Is64BitProcess)
LoadNvApi64();
else
LoadNvApi32();
}
catch { } // will always fail since 'fake' entry point doesn't exists
}
重要提示 - 在创建任何窗口之前请调用InitializeDedicatedGraphics()
NativeLibrary.Load("nvapi64.dll")或等效的32位版本。当然，您仍需要使用try catch来处理错误，但这比定义虚拟P/Invoke存根来加载库要简短得多。 - Pieter-Jan Briers我尝试了the swine提供的两个选项，但它们本身都不起作用。我发现需要尝试调用已导入的函数。
using System.Runtime.InteropServices;
class OptimusEnabler
{
[DllImport("nvapi.dll")]
public static extern int NvAPI_Initialize();
};
然后在我的应用启动时：
try
{
///Ignore any System.EntryPointNotFoundException
///or System.DllNotFoundException exceptions here
OptimusEnabler.NvAPI_Initialize();
}
catch
{ }
System.EntryPointNotFoundException的问题，但仍然可以让应用程序使用nVidia硬件。在具有ATI卡的系统上进行测试，我得到了一个System.DllNotFoundException。无论哪种方式，尝试调用此函数并忽略任何异常都似乎运行良好。NvAPI_Status status;
// (0) Initialize NVAPI. This must be done first of all
status = NvAPI_Initialize();
if (status != NVAPI_OK)
PrintError(status, __LINE__);
// (1) Create the session handle to access driver settings
NvDRSSessionHandle hSession = 0;
status = NvAPI_DRS_CreateSession(&hSession);
if (status != NVAPI_OK)
PrintError(status, __LINE__);
// (2) load all the system settings into the session
status = NvAPI_DRS_LoadSettings(hSession);
if (status != NVAPI_OK)
PrintError(status, __LINE__);
// (3) Obtain the Base profile. Any setting needs to be inside
// a profile, putting a setting on the Base Profile enforces it
// for all the processes on the system
NvDRSProfileHandle hProfile = 0;
status = NvAPI_DRS_GetBaseProfile(hSession, &hProfile);
if (status != NVAPI_OK)
PrintError(status, __LINE__);
NVDRS_SETTING drsSetting1 = {0};
drsSetting1.version = NVDRS_SETTING_VER;
drsSetting1.settingId = SHIM_MCCOMPAT_ID;
drsSetting1.settingType = NVDRS_DWORD_TYPE;
NVDRS_SETTING drsSetting2 = {0};
drsSetting2.version = NVDRS_SETTING_VER;
drsSetting2.settingId = SHIM_RENDERING_MODE_ID;
drsSetting2.settingType = NVDRS_DWORD_TYPE;
NVDRS_SETTING drsSetting3 = {0};
drsSetting3.version = NVDRS_SETTING_VER;
drsSetting3.settingId = SHIM_RENDERING_OPTIONS_ID;
drsSetting3.settingType = NVDRS_DWORD_TYPE;
if( ForceIntegrated ){
drsSetting1.u32CurrentValue = SHIM_MCCOMPAT_INTEGRATED;
drsSetting2.u32CurrentValue = SHIM_RENDERING_MODE_INTEGRATED;
drsSetting3.u32CurrentValue = SHIM_RENDERING_OPTIONS_DEFAULT_RENDERING_MODE | SHIM_RENDERING_OPTIONS_IGPU_TRANSCODING;
}else{
drsSetting1.u32CurrentValue = SHIM_MCCOMPAT_ENABLE;
drsSetting2.u32CurrentValue = SHIM_RENDERING_MODE_ENABLE;
drsSetting3.u32CurrentValue = SHIM_RENDERING_OPTIONS_DEFAULT_RENDERING_MODE;
}
status = NvAPI_DRS_SetSetting(hSession, hProfile, &drsSetting1);
if (status != NVAPI_OK)
PrintError(status, __LINE__);
status = NvAPI_DRS_SetSetting(hSession, hProfile, &drsSetting2);
if (status != NVAPI_OK)
PrintError(status, __LINE__);
status = NvAPI_DRS_SetSetting(hSession, hProfile, &drsSetting3);
if (status != NVAPI_OK)
PrintError(status, __LINE__);
// (5) Now we apply (or save) our changes to the system
status = NvAPI_DRS_SaveSettings(hSession);
if (status != NVAPI_OK)
PrintError(status, __LINE__);
// (6) We clean up. This is analogous to doing a free()
NvAPI_DRS_DestroySession(hSession);
hSession = 0;
// Applications exporting this symbol with this value will be automatically
// directed to the high-performance GPU on nVidia Optimus systems
//
GLFWAPI DWORD NvOptimusEnablement = 0x00000001;
我面临使用NVIDIA和AMD GPU的需求。在我的网络冒险中，我发现了nvpatch，这是一个应用程序，可以添加必要的标头来使用专用GPU。然而，这个应用程序仅适用于x64，因此我最终创建了EditBinPE，通过它可以编辑PE文件的头部，在其中添加必要的标头以使用AmdPowerXpressRequestHighPerformance和NvOptimusEnablement。为了启用AmdPowerXpressRequestHighPerformance和NvOptimusEnablement，您必须使用以下两个应用程序之一，nvpatch和EditBinPE。这两个应用程序用于编辑PE32文件的头部（只有editbinpe可以处理此类型的文件）和PE32+。
EditBinPE 命令： editbinpe --enable-gpu filename.exe
仅限 AMD 的命令： editbinpe --enable filename.exe AmdPowerXpressRequestHighPerformance
仅限 NVIDIA 的命令： editbinpe --enable filename.exe NvOptimusEnablement
nvpatch 命令： nvpatch --enable filename.exe
如果只想使用 NVIDIA，请使用此功能：
static void InitializeDedicatedGraphics()
{
if (Environment.Is64BitProcess)
NativeLibrary.Load("nvapi64.dll");
else
NativeLibrary.Load("nvapi.dll");
}
我的解决方案适用于NVidia和AMD，不需要使用DllExport（也不需要NuGet包UnmanagedExports），基于导出函数NvOptimusEnablement和AmdPowerXpressRequestHighPerformance：
在VS2019上，前面提到的UnmanagedExports包似乎无法正常工作。我找不到另一个为.NET框架提供DllExport功能的工作包。这就是为什么我使用直接的MSIL代码开发了自己的解决方案，在Visual Studio上编写IL代码和IL Support给了我很大的帮助。
按照以下步骤操作：
To .csproj file (.csproj for exe, not for any dll) add the following section which enables direct usage of MSIL code (you may put it generally anywhere, i.e. after <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />). For .net frameworks newer than 4.6.2 you may need to update paths to ildasm.exe:
<PropertyGroup>
<CoreCompileDependsOn>
HideILFromCoreCompile;
$(CoreCompileDependsOn);
</CoreCompileDependsOn>
<CompileDependsOn>
HideILFromCompile;
$(CompileDependsOn);
InitializeIL;
CoreDecompile;
CoreCompileIL;
</CompileDependsOn>
</PropertyGroup>
<Target Name="HideILFromCoreCompile">
<ItemGroup>
<Compile Remove="@(Compile)" Condition="'%(Extension)'=='.il'" />
</ItemGroup>
</Target>
<Target Name="HideILFromCompile">
<ItemGroup>
<IL Include="@(Compile)" Condition="'%(Extension)'=='.il'" />
<Compile Remove="@(Compile)" Condition="'%(Extension)'=='.il'" />
</ItemGroup>
</Target>
<Target Name="InitializeIL">
<PropertyGroup>
<ILFile>@(IntermediateAssembly->'%(RootDir)%(Directory)%(Filename).il', ' ')</ILFile>
<ILResourceFile>@(IntermediateAssembly->'%(RootDir)%(Directory)%(Filename).res', ' ')</ILResourceFile>
</PropertyGroup>
</Target>
<Target Name="CoreDecompile" Inputs="@(IntermediateAssembly)" Outputs="$(ILFile)" Condition=" Exists ( @(IntermediateAssembly) ) ">
<GetFrameworkSdkPath>
<Output TaskParameter="Path" PropertyName="FrameworkSdkPath" />
</GetFrameworkSdkPath>
<PropertyGroup>
<ILDasm>"$(FrameworkSdkPath)bin\ildasm.exe" /nobar /linenum /output:"$(ILFile)" @(IntermediateAssembly->'"%(FullPath)"', ' ')</ILDasm>
</PropertyGroup>
<PropertyGroup Condition=" Exists ( '$(FrameworkSdkPath)bin\NETFX 4.0 Tools\ildasm.exe' ) ">
<ILDasm>"$(FrameworkSdkPath)bin\NETFX 4.0 Tools\ildasm.exe" /nobar /linenum /output:"$(ILFile)" @(IntermediateAssembly->'"%(FullPath)"', ' ')</ILDasm>
</PropertyGroup>
<PropertyGroup Condition=" Exists ( '$(FrameworkSdkPath)bin\NETFX 4.5.1 Tools\ildasm.exe' ) ">
<ILDasm>"$(FrameworkSdkPath)bin\NETFX 4.5.1 Tools\ildasm.exe" /nobar /linenum /output:"$(ILFile)" @(IntermediateAssembly->'"%(FullPath)"', ' ')</ILDasm>
</PropertyGroup>
<PropertyGroup Condition=" Exists ( '$(FrameworkSdkPath)bin\NETFX 4.6 Tools\ildasm.exe' ) ">
<ILDasm>"$(FrameworkSdkPath)bin\NETFX 4.6 Tools\ildasm.exe" /nobar /linenum /output:"$(ILFile)" @(IntermediateAssembly->'"%(FullPath)"', ' ')</ILDasm>
</PropertyGroup>
<PropertyGroup Condition=" Exists ( '$(FrameworkSdkPath)bin\NETFX 4.6.1 Tools\ildasm.exe' ) ">
<ILDasm>"$(FrameworkSdkPath)bin\NETFX 4.6.1 Tools\ildasm.exe" /nobar /linenum /output:"$(ILFile)" @(IntermediateAssembly->'"%(FullPath)"', ' ')</ILDasm>
</PropertyGroup>
<PropertyGroup Condition=" Exists ( '$(FrameworkSdkPath)bin\NETFX 4.6.2 Tools\ildasm.exe' ) ">
<ILDasm>"$(FrameworkSdkPath)bin\NETFX 4.6.2 Tools\ildasm.exe" /nobar /linenum /output:"$(ILFile)" @(IntermediateAssembly->'"%(FullPath)"', ' ')</ILDasm>
</PropertyGroup>
<Exec Command="$(ILDasm)" />
<ItemGroup>
<FileWrites Include="$(ILFile)" />
<FileWrites Include="$(ILResourceFile)" />
</ItemGroup>
<PropertyGroup>
<ILSource>$([System.IO.File]::ReadAllText($(ILFile)))</ILSource>
<Replacement>// method ${method} forwardref removed for IL import</Replacement>
<Pattern>\.method [^{}]+ cil managed forwardref[^}]+} // end of method (?<method>[^ \r\t\n]+)</Pattern>
<ILSource>$([System.Text.RegularExpressions.Regex]::Replace($(ILSource), $(Pattern), $(Replacement)))</ILSource>
<Pattern>\.method [^{}]+ cil managed[^\a]+"extern was not given a DllImport attribute"[^}]+} // end of method (?<method>[^ \r\t\n]+)</Pattern>
<ILSource>$([System.Text.RegularExpressions.Regex]::Replace($(ILSource), $(Pattern), $(Replacement)))</ILSource>
</PropertyGroup>
<WriteLinesToFile File="$(ILFile)" Lines="$(ILSource)" Overwrite="true" />
<PropertyGroup>
<ILSource />
</PropertyGroup>
<Delete Files="@(IntermediateAssembly)" />
</Target>
<Target Name="CoreCompileIL" Inputs="@(IL)" Outputs="@(IntermediateAssembly)">
<GetFrameworkPath>
<Output TaskParameter="Path" PropertyName="FrameworkPath" />
</GetFrameworkPath>
<PropertyGroup>
<ILAsm>"$(FrameworkPath)\ilasm.exe" /nologo /quiet /output:@(IntermediateAssembly->'"%(FullPath)"', ' ')</ILAsm>
</PropertyGroup>
<PropertyGroup Condition=" '$(FileAlignment)' != '' ">
<ILAsm>$(ILAsm) /alignment=$(FileAlignment)</ILAsm>
</PropertyGroup>
<PropertyGroup Condition=" '$(BaseAddress)' != '' ">
<ILAsm>$(ILAsm) /base=$(BaseAddress)</ILAsm>
</PropertyGroup>
<PropertyGroup Condition=" '$(OutputType)' == 'Library' ">
<ILAsm>$(ILAsm) /dll</ILAsm>
</PropertyGroup>
<PropertyGroup Condition=" '$(DebugType)' == 'pdbonly' ">
<ILAsm>$(ILAsm) /pdb</ILAsm>
</PropertyGroup>
<PropertyGroup Condition=" '$(DebugType)' == 'full' ">
<ILAsm>$(ILAsm) /debug</ILAsm>
</PropertyGroup>
<PropertyGroup Condition=" '$(Optimize)' == 'true' ">
<ILAsm>$(ILAsm) /optimize</ILAsm>
</PropertyGroup>
<PropertyGroup Condition=" '$(Platform)' == 'x64' ">
<ILAsm>$(ILAsm) /pe64 /x64</ILAsm>
</PropertyGroup>
<PropertyGroup Condition=" '$(Platform)' == 'Itanium' ">
<ILAsm>$(ILAsm) /pe64 /itanium</ILAsm>
</PropertyGroup>
<PropertyGroup Condition=" '$(AssemblyOriginatorKeyFile)' != '' ">
<ILAsm>$(ILAsm) /key:"$(AssemblyOriginatorKeyFile)"</ILAsm>
</PropertyGroup>
<PropertyGroup Condition=" Exists ( '$(ILResourceFile)' ) ">
<ILAsm>$(ILAsm) /resource:"$(ILResourceFile)"</ILAsm>
</PropertyGroup>
<PropertyGroup Condition=" Exists ( '$(ILFile)' ) ">
<ILAsm>$(ILAsm) "$(ILFile)"</ILAsm>
</PropertyGroup>
<Exec Command="$(ILAsm) @(IL->'"%(FullPath)"', ' ')" />
<ItemGroup>
<FileWrites Include="@(IntermediateAssembly->'%(RootDir)%(Directory)DesignTimeResolveAssemblyReferencesInput.cache', ' ')" />
</ItemGroup>
<Touch Files="$(ILFile)" />
</Target>
Paste the code below to this file (instead of 'WindowsApplication1' you may enter your namespace):
.class public WindowsApplication1.ForceDedicatedGraphicCard
{
.method public static int32 NvOptimusEnablement() cil managed
{
.export [1]
ldc.i4.1
ret
}
.method public static uint32 AmdPowerXpressRequestHighPerformance() cil managed
{
.export [2]
ldc.i4.1
ret
}
}
Check if the functions are exported using dumpbin.exe
dumpbin.exe /exports your_project.exe
从文档中看起来相当简单。你有多种选项可以这样做。不幸的是，需要执行exe而不是dll来完成。根据this tutorial，可能可以尝试像这样做：
class OptimusEnabler {
[DllExport("NvOptimusEnablement")]
public static int NvOptimusEnablement = 1;
};
然后需要将其包含在您的C++库接口中，以便使用它的任何C#应用程序都必须导出此内容。或者，您可以尝试链接到nvapi.dll：
class OptimusEnabler {
[DllImport("nvapi.dll")]
public static extern int NvAPI_Initialize();
};