关于#.net# System.Private.CoreLib.dll的问题，请问如何解决？

Question

.net c# 目标框架.NET Standard2.1
有大量的代码提示缺少System.Private.CoreLib.dll

但是如果我引用了这个System.Private.CoreLib.dll, 整个项目就没法用System.Object,System.String
比如提示
错误 CS0518 预定义类型“System.Object”未定义或导入
预定义类型“System.Void”未定义或导入

---

没有删其他的using 是System.Private.CoreLib.dll里面也有System.String,
导致System.String 存在两个DLL里
好像要用别名,但是试了一下没成功

Answer 1

可能你弄混了不同版本的System.Private.CoreLib.dll
仅供参考：

date       time            size      fullpath
2017-04-11 19:49:36        2323672   C:\Users\Administrator\.nuget\packages\runtime.win7-x64.microsoft.netcore.runtime.coreclr\1.0.7\runtimes\win7-x64\lib\netstandard1.0\System.Private.CoreLib.dll
2022-03-18 16:01:34        2397648   C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\CoreCon\Binaries\Phone Tools\Debugger\CoreClr\x64\System.Private.CoreLib.dll
2021-12-10 11:19:53        8579976   C:\Users\Administrator\.vscode\extensions\ms-vscode.cpptools-1.7.1\debugAdapters\bin\System.Private.CoreLib.dll
2022-04-14 01:38:24        8581544   C:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App\5.0.17\System.Private.CoreLib.dll
2022-01-21 15:09:56        8744528   C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\Common7\IDE\Extensions\Microsoft\LiveShare\Agent\System.Private.CoreLib.dll
2022-11-09 19:36:46        8748960   C:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App\3.1.32\System.Private.CoreLib.dll
2020-10-19 19:10:06        9389960   D:\dnSpy-net-win64\bin\System.Private.CoreLib.dll
2022-04-14 01:43:02        9395632   C:\Program Files\dotnet\shared\Microsoft.NETCore.App\5.0.17\System.Private.CoreLib.dll
2021-06-21 13:21:32        9558920   D:\detect_old\soft\netcoreapp3.1\publish\System.Private.CoreLib.dll
2021-09-21 01:31:50        9559936   C:\Users\Administrator\.nuget\packages\microsoft.netcore.app.runtime.win-x64\3.1.20\runtimes\win-x64\native\System.Private.CoreLib.dll
2021-11-19 08:55:44        9559944   C:\Users\Administrator\.nuget\packages\microsoft.netcore.app.runtime.win-x64\3.1.22\runtimes\win-x64\native\System.Private.CoreLib.dll
2021-10-15 02:54:26        9559952   C:\Users\Administrator\.nuget\packages\microsoft.netcore.app.runtime.win-x64\3.1.21\runtimes\win-x64\native\System.Private.CoreLib.dll
2022-02-17 06:14:08        9560448   C:\Users\Administrator\.nuget\packages\microsoft.netcore.app.runtime.win-x64\3.1.23\runtimes\win-x64\native\System.Private.CoreLib.dll
2022-03-15 03:56:34        9561488   C:\Users\Administrator\.nuget\packages\microsoft.netcore.app.runtime.win-x64\3.1.24\runtimes\win-x64\native\System.Private.CoreLib.dll
2022-11-09 19:41:02        9561536   C:\Program Files\dotnet\shared\Microsoft.NETCore.App\3.1.32\System.Private.CoreLib.dll
2023-01-25 01:30:38        9992840   C:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App\6.0.14\System.Private.CoreLib.dll
2022-03-28 20:03:10        9994384   C:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App\6.0.4\System.Private.CoreLib.dll
2022-10-24 23:52:20        9995392   C:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App\6.0.11\System.Private.CoreLib.dll
2023-01-25 01:29:18       10626736   C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.14\System.Private.CoreLib.dll
2022-10-24 23:50:58       10630312   C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.11\System.Private.CoreLib.dll
2022-07-22 14:46:18       10630792   C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.8\System.Private.CoreLib.dll
2022-03-28 20:02:20       10631320   C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.4\System.Private.CoreLib.dll
2023-01-20 20:13:02       10987688   C:\Program Files (x86)\dotnet\shared\Microsoft.NETCore.App\7.0.3\System.Private.CoreLib.dll
2023-01-20 20:13:14       11651240   C:\Program Files\dotnet\shared\Microsoft.NETCore.App\7.0.3\System.Private.CoreLib.dll
2021-08-11 23:05:30       13026168   C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.1.30\System.Private.CoreLib.dll
2020-07-31 04:17:36       13026184   C:\Users\Administrator\.nuget\packages\runtime.win-x64.microsoft.netcore.app\2.1.21\runtimes\win-x64\native\System.Private.CoreLib.dll
2021-04-16 01:40:00       13026192   C:\Users\Administrator\.nuget\packages\runtime.win-x64.microsoft.netcore.app\2.1.28\runtimes\win-x64\native\System.Private.CoreLib.dll
2019-04-17 16:54:36       13033008   C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.1.11\System.Private.CoreLib.dll

IL_0045: call int32 [netstandard]System.Convert::ToInt32(float64)
改为
IL_0045: Ldc_I4 100

结账吧