VS 2017 c# Error CS0234命名空间中不存在类型或命名空间名称(是否缺少程序集引用？)

Question

我有一个包含多个项目的解决方案。我有正确的构建顺序和依赖关系。此项目可以使用与Visual Studio2017 (26430.13)完全相同的版本在不同的计算机上构建。唯一不同的是，目前我正在尝试在Windows10上构建，另一个系统(可以构建)是Win 8.1。但是在第三台安装了Win 10的机器上也可以构建。

我的问题是系统上的以下问题，它不能构建解决方案：

有一个名为ucx.v2 (命名空间: pcbox)的项目。当我构建这个项目时，没有错误，它构建正确。

还有另一个项目叫做Timer。此项目在参考资料中引用了ucx.v2。它没坏。当我构建这个项目时，我得到了100多个错误，关于引用错误。

构建顺序是正确的，因为当我构建Timer项目时，它首先开始构建ucx.v2项目，然后在没有任何错误的情况下完成。

我已经尝试了以下方法：-重新启动VS。-清理解决方案，重建项目-从计时器项目中移除引用，然后再次添加它。

注意:我已经从运行的机器上复制了解决方案。

以下是错误日志：

1>------ Build started: Project: ucx.v2, Configuration: Debug Any CPU ------
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\forms\UcDataAdapter.cs(463,21,463,28): warning CS0108: 'UcDataAdapter.Dispose()' hides inherited member 'Component.Dispose()'. Use the new keyword if hiding was intended.
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\ras\RasConnectionNotify.cs(35,69,35,93): warning CS0618: 'WaitHandle.Handle' is obsolete: 'Use the SafeWaitHandle property instead.'
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\ras\RasConnectionNotify.cs(52,69,52,93): warning CS0618: 'WaitHandle.Handle' is obsolete: 'Use the SafeWaitHandle property instead.'
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\data\CommandBatch.cs(53,34,53,36): warning CS0168: The variable 'ex' is declared but never used
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\ras\RasConnection.cs(440,59,440,84): warning CS0618: 'WaitHandle.Handle' is obsolete: 'Use the SafeWaitHandle property instead.'
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\data\StoredProc.cs(58,13,58,16): warning CS0162: Unreachable code detected
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\data\StoredProc.cs(81,13,81,16): warning CS0162: Unreachable code detected
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\forms\UcColorButton.cs(23,17,23,49): warning CS0184: The given expression is never of the provided ('KnownColor') type
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\data\QueryOptimizer.cs(258,18,258,26): warning CS0219: The variable 'sendflag' is assigned but its value is never used
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\forms\Print\ReportToolbar.cs(119,30,119,32): warning CS0168: The variable 'ex' is declared but never used
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\forms\UcDataSetManager.cs(1172,37,1172,39): warning CS0168: The variable 'ex' is declared but never used
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\forms\Print\frmReportPreview.Designer.cs(140,56,140,64): warning CS0169: The field 'frmReportPreview.Command0' is never used
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\ras\frmGetConnection.cs(22,44,22,54): warning CS0649: Field 'frmGetConnection.components' is never assigned to, and will always have its default value null
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\forms\MemoryStatisticsGparh.cs(33,13,33,30): warning CS0414: The field 'MemoryStatisticsGparh.graphMaxItemCount' is assigned but its value is never used
1>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\forms\MemoryStatisticsGparh.cs(32,13,32,22): warning CS0414: The field 'MemoryStatisticsGparh.lineCount' is assigned but its value is never used
1>  ucx.v2 -> c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\bin\Debug\ucx.v2.dll
2>------ Build started: Project: Timer, Configuration: Debug Any CPU ------
3>------ Build started: Project: pcbox.startpage, Configuration: Debug Any CPU ------
4>------ Build started: Project: Loader.run, Configuration: Debug Any CPU ------
2>C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin\Microsoft.Common.CurrentVersion.targets(1964,5): warning MSB3258: The primary reference "c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\bin\Debug\ucx.v2.dll" could not be resolved because it has an indirect dependency on the .NET Framework assembly "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which has a higher version "4.0.0.0" than the version "2.0.0.0" in the current target framework.
2>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\Timer\AlarmNotification.cs(6,13,6,17): error CS0234: The type or namespace name 'data' does not exist in the namespace 'pcbox' (are you missing an assembly reference?)
2>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\Timer\IScheduledServiceItem.cs(2,13,2,17): error CS0234: The type or namespace name 'data' does not exist in the namespace 'pcbox' (are you missing an assembly reference?)
2>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\Timer\pop3\RxMailMessage.cs(17,13,17,22): error CS0234: The type or namespace name 'Extension' does not exist in the namespace 'pcbox' (are you missing an assembly reference?)
2>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\Timer\ServiceTimer.cs(8,13,8,17): error CS0234: The type or namespace name 'data' does not exist in the namespace 'pcbox' (are you missing an assembly reference?)
2>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\Timer\ServiceTimerDS.cs(4,13,4,17): error CS0234: The type or namespace name 'data' does not exist in the namespace 'pcbox' (are you missing an assembly reference?)
2>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\Timer\synchronization\MailReceiver.cs(7,13,7,17): error CS0234: The type or namespace name 'data' does not exist in the namespace 'pcbox' (are you missing an assembly reference?)
2>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\Timer\synchronization\MailSender.cs(8,13,8,17): error CS0234: The type or namespace name 'data' does not exist in the namespace 'pcbox' (are you missing an assembly reference?)
2>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\Timer\synchronization\Replication.cs(6,7,6,18): error CS0246: The type or namespace name 'ICSharpCode' could not be found (are you missing a using directive or an assembly reference?)
2>c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\Timer\synchronization\Replication.cs(7,13,7,17): error CS0234: The type or namespace name 'data' does not exist in the namespace 'pcbox' (are you missing an assembly reference?)

Answer 1

我相信你的问题是由于这里的这一行：

2>C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin\Microsoft.Common.CurrentVersion.targets(1964,5): warning MSB3258: The primary reference "c:\Users\david\Documents\Visual Studio 2017\Projects\NomalGit\ucx.v2\bin\Debug\ucx.v2.dll" could not be resolved because it has an indirect dependency on the .NET Framework assembly "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which has a higher version "4.0.0.0" than the version "2.0.0.0" in the current target framework.

在名为Timer的项目中，通过打开项目属性并更改"Target Framework“，将.NET目标版本从2.0更改为4.0。