改变目标框架

Posted 2023-03-05

【中文标题】改变目标框架

【英文标题】：Changing target framework

【发布时间】：2011-05-10 07:31:40

【问题描述】：

在 Visual Studio 2010 Express [VB.NET] 中，如果我通过应用程序属性 > 编译 > 高级编译选项将目标框架从 4.0 更改为框架 2.0，我会得到一个错误列表：

Warning 5   The referenced component 'System.Xml.Linq' could not be found.  
Warning 6   The referenced component 'System.Data.DataSetExtensions' could not be found.    
Warning 4   The referenced component 'System.Core' could not be found.  
Warning 2   The primary reference "System.Xml.Linq", which is a framework assembly, could not be resolved in the currently targeted framework. ".NETFramework,Version=v2.0". To resolve this problem, either remove the reference "System.Xml.Linq" or retarget your application to a framework version which contains "System.Xml.Linq".   WindowsApplication3
Warning 3   The primary reference "System.Data.DataSetExtensions", which is a framework assembly, could not be resolved in the currently targeted framework. ".NETFramework,Version=v2.0". To resolve this problem, either remove the reference "System.Data.DataSetExtensions" or retarget your application to a framework version which contains "System.Data.DataSetExtensions". WindowsApplication3
Warning 1   The primary reference "System.Core", which is a framework assembly, could not be resolved in the currently targeted framework. ".NETFramework,Version=v2.0". To resolve this problem, either remove the reference "System.Core" or retarget your application to a framework version which contains "System.Core".   WindowsApplication3
Warning 7   Namespace or type specified in the project-level Imports 'System.Xml.Linq' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases.   WindowsApplication3
Warning 8   Namespace or type specified in the project-level Imports 'System.Linq' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases.   WindowsApplication3

我已经四处搜索，但似乎找不到我认为对我有用的答案。我只是在使用一个没有任何内容的空白项目。

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Warning 1   Namespace or type specified in the project-level Imports 'System.Xml.Linq' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases.   WindowsApplication3
Warning 2   Namespace or type specified in the project-level Imports 'System.Linq' doesn't contain any public member or cannot be found. Make sure the namespace or the type is defined and contains at least one public member. Make sure the imported element name doesn't use any aliases.   WindowsApplication3

【参考方案1】：

尝试删除项目中对以下内容的引用：

System.Xml.Linq
System.Data.DataSetExtensions
System.Core

它们是由 VS2010 express 自动添加的。

您可以通过展开引用树、突出显示引用并点击删除来做到这一点。

【讨论】：

啊，谢谢，那行得通。没想到会这么简单。但是我仍然收到警告

奇怪，我尝试做与目前完全相同的操作，但这次它消除了错误。 TYVM。

我遇到了同样的问题，只是它没有显示在参考树中。我必须进入项目属性中的引用，并删除导入命名空间下的复选标记。