我并排安装了 Visual Studio 2013 和 2015。我刚刚将组合解决方案（C#、C++、C++/CLI）升级到 2015 并将 Platform Toolset 设置为 v140。
Visual Studio 的构建工作正常，但不能从 MSBuild 编译。我用的是MSBuild 14，MSBuild抱怨找不到v140，但这是无稽之谈，因为v140安装在计算机上的“c:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140”中。
关于升级解决方案的建议无法完成，因为解决方案已经升级并且解决方案上下文菜单中没有此类项目。
如果我将项目的平台工具切换到 v120，它就可以工作。
细节：
c:\git\hewerMaster>"c:\Program Files (x86)\MSBuild\14.0\Bin\MSBuild.exe" c:\git
\hewerMaster\Hewer.sln /property:Configuration=Debug /property:Platform=x86
Microsoft (R) Build Engine version 14.0.23107.0
Copyright (C) Microsoft Corporation. All rights reserved.
Building the projects in this solution one at a time. To enable parallel build,
please add the "/m" switch.
Build started 9/12/2015 4:00:25 PM.
Project "c:\git\hewerMaster\Hewer.sln" on node 1 (default targets).
ValidateSolutionConfiguration:
Building solution configuration "Debug|x86".
ValidateProjects:
The project "HewerDotNetWrapper" is not selected for building in solution con
figuration "Debug|x86".
The project "VisualHewer" is not selected for building in solution configurat
ion "Debug|x86".
The project "UnitTestWrapper" is not selected for building in solution config
uration "Debug|x86".
The project "ParamsFormatConverter" is not selected for building in solution
configuration "Debug|x86".
The project "UnitTestGenerator" is not selected for building in solution conf
iguration "Debug|x86".
The project "HewerUnitTestDotNet" is not selected for building in solution co
nfiguration "Debug|x86".
Project "c:\git\hewerMaster\Hewer.sln" (1) is building "c:\git\hewerMaster\Hewe
rRedirect\HewerRedirect.csproj" (2) on node 1 (default targets).
CoreCompile:
Skipping target "CoreCompile" because all output files are up-to-date with resp
ect to the input files.
_CopyAppConfigFile:
Skipping target "_CopyAppConfigFile" because all output files are up-to-date wi
th respect to the input files.
CopyFilesToOutputDirectory:
HewerRedirect -> c:\git\hewerMaster\anyCPU\Debug\pbrain-hewer.exe
Done Building Project "c:\git\hewerMaster\HewerRedirect\HewerRedirect.csproj" (
default targets).
Project "c:\git\hewerMaster\Hewer.sln" (1) is building "c:\git\hewerMaster\Hewe
r\Hewer.vcxproj" (3) on node 1 (default targets).
C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\Microsoft.Cpp.Platform.t
argets(64,5): error MSB8020: The build tools for v140 (Platform Toolset = 'v140
') cannot be found. To build using the v140 build tools, please install v140 bu
ild tools. Alternatively, you may upgrade to the current Visual Studio tools b
y selecting the Project menu or right-click the solution, and then selecting "U
pgrade Solution...". [c:\git\hewerMaster\Hewer\Hewer.vcxproj]
Done Building Project "c:\git\hewerMaster\Hewer\Hewer.vcxproj" (default targets
) -- FAILED.
Done Building Project "c:\git\hewerMaster\Hewer.sln" (default targets) -- FAILE
D.
Build FAILED.
更新：
- 从 Debug X86 中跳过了一些项目。这是故意的。
- 该项目最初是在VS2008中创建的，然后升级到VS2013，然后升级到VS2015。
- 这台计算机上安装了两个 Visual Studio（2013 Community 和 2015 Community）。先安装2013，后安装2015。
注册表设置如下所示：
UPDATE2： 最小、完整和可验证的示例
我在 Visual Studio 2015 中创建了空的 C++ 控制台应用程序：
https://dl.dropboxusercontent.com/u/53387801/ConsoleApplication_v140.zip
#include "stdafx.h"
int main()
{
return 0;
}
我可以在 Visual Studio 中构建它，但我在 MSBuild 中遇到了同样的问题：
c:\>"c:\Program Files (x86)\MSBuild\14.0\Bin\MSBuild" "C:\temp\vs2015_simplest\C
onsoleApplication1\consoleApplication1.sln"
Microsoft (R) Build Engine version 14.0.23107.0
Copyright (C) Microsoft Corporation. All rights reserved.
Building the projects in this solution one at a time. To enable parallel build,
please add the "/m" switch.
Build started 9/16/2015 10:16:20 AM.
Project "C:\temp\vs2015_simplest\ConsoleApplication1\consoleApplication1.sln" o
n node 1 (default targets).
ValidateSolutionConfiguration:
Building solution configuration "Debug|x64".
Project "C:\temp\vs2015_simplest\ConsoleApplication1\consoleApplication1.sln" (
1) is building "C:\temp\vs2015_simplest\ConsoleApplication1\ConsoleApplication1
\ConsoleApplication1.vcxproj" (2) on node 1 (default targets).
C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\Microsoft.Cpp.Platform.t
argets(64,5): error MSB8020: The build tools for v140 (Platform Toolset = 'v140
') cannot be found. To build using the v140 build tools, please install v140 bu
ild tools. Alternatively, you may upgrade to the current Visual Studio tools b
y selecting the Project menu or right-click the solution, and then selecting "U
pgrade Solution...". [C:\temp\vs2015_simplest\ConsoleApplication1\ConsoleApplic
ation1\ConsoleApplication1.vcxproj]
Done Building Project "C:\temp\vs2015_simplest\ConsoleApplication1\ConsoleAppli
cation1\ConsoleApplication1.vcxproj" (default targets) -- FAILED.
Done Building Project "C:\temp\vs2015_simplest\ConsoleApplication1\consoleAppli
cation1.sln" (default targets) -- FAILED.
Build FAILED.
"C:\temp\vs2015_simplest\ConsoleApplication1\consoleApplication1.sln" (default
target) (1) ->
"C:\temp\vs2015_simplest\ConsoleApplication1\ConsoleApplication1\ConsoleApplica
tion1.vcxproj" (default target) (2) ->
(PlatformPrepareForBuild target) ->
C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\Microsoft.Cpp.Platform
.targets(64,5): error MSB8020: The build tools for v140 (Platform Toolset = 'v1
40') cannot be found. To build using the v140 build tools, please install v140
build tools. Alternatively, you may upgrade to the current Visual Studio tools
by selecting the Project menu or right-click the solution, and then selecting
"Upgrade Solution...". [C:\temp\vs2015_simplest\ConsoleApplication1\ConsoleAppl
ication1\ConsoleApplication1.vcxproj]
0 Warning(s)
1 Error(s)
Time Elapsed 00:00:00.14
c:\>
解决了：
环境变量 VisualStudioVersion 设置为 12.0 而不是 14.0将值更改为 14.0 解决了该问题。
简单的控制台应用程序在环境变量 VisualStudioVersion 更改和 Windows 注销后立即开始工作，登录。
更改环境变量 VisualStudioVersion 后仍无法构建原始项目。Visual Studio 2015 中出现了重定向解决方案上下文菜单。所以我重新定位解决方案。重新定位后，仍然无法编译解决方案（未找到 v140）。最后，我将平台工具集从v140 (not installed)更改为Visual Studio 2015 (v140)。现在该解决方案也可以从 Visual Studio 和 MSBuild 编译。