如何使Visual Studio 2010在Windows Phone项目中使用.NET 4.0而不是.NET 2.0？

Question

这是一个Windows Phone 7项目.

出于某些奇怪的原因,Visual Studio 2010不允许我在项目设置"应用程序"选项卡中将目标.NET版本设置为.NET 4.0.它变灰了.

当我编译项目时,XNA程序集是.NET 4.0,但System和System.Core以及其余所有程序都是.NET 2.0.

当我说"添加引用"时,它不会让我选择任何.NET 4.0系统程序集,如mscorlib.

我卸载了.NET 4.0,然后重新安装它.没有帮助.

编辑:我的最终目标是让这个编译.为什么为系统程序集选择.NET 2.0？

编辑:我收到这些错误:

C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1360,9): warning MSB3268: The primary reference "Microsoft.Xna.Framework.Video" could not be resolved because it has an indirect dependency on the framework assembly "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v4.0,Profile=Client". To resolve this problem, either remove the reference "Microsoft.Xna.Framework.Video" or retarget your application to a framework version which contains "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089".
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1360,9): warning MSB3268: The primary reference "Microsoft.Xna.Framework.Net" could not be resolved because it has an indirect dependency on the framework assembly "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v4.0,Profile=Client". To resolve this problem, either remove the reference "Microsoft.Xna.Framework.Net" or retarget your application to a framework version which contains "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089".
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1360,9): warning MSB3268: The primary reference "Microsoft.Xna.Framework.Avatar" could not be resolved because it has an indirect dependency on the framework assembly "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v4.0,Profile=Client". To resolve this problem, either remove the reference "Microsoft.Xna.Framework.Avatar" or retarget your application to a framework version which contains "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089".
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1360,9): warning MSB3268: The primary reference "Microsoft.Xna.Framework.Storage" could not be resolved because it has an indirect dependency on the framework assembly "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v4.0,Profile=Client". To resolve this problem, either remove the reference "Microsoft.Xna.Framework.Storage" or retarget your application to a framework version which contains "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089".
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1360,9): warning MSB3268: The primary reference "Microsoft.Xna.Framework.Xact" could not be resolved because it has an indirect dependency on the framework assembly "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v4.0,Profile=Client". To resolve this problem, either remove the reference "Microsoft.Xna.Framework.Xact" or retarget your application to a framework version which contains "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089".
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1360,9): warning MSB3268: The primary reference "Microsoft.Xna.Framework.Net" could not be resolved because it has an indirect dependency on the framework assembly "System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v4.0,Profile=Client". To resolve this problem, either remove the reference "Microsoft.Xna.Framework.Net" or retarget your application to a framework version which contains "System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089".
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1360,9): warning MSB3268: The primary reference "Microsoft.Xna.Framework.Xact" could not be resolved because it has an indirect dependency on the framework assembly "System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v4.0,Profile=Client". To resolve this problem, either remove the reference "Microsoft.Xna.Framework.Xact" or retarget your application to a framework version which contains "System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089".
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1360,9): warning MSB3268: The primary reference "Microsoft.Xna.Framework.Xact" could not be resolved because it has an indirect dependency on the framework assembly "System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v4.0,Profile=Client". To resolve this problem, either remove the reference "Microsoft.Xna.Framework.Xact" or retarget your application to a framework version which contains "System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089".
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1360,9): warning MSB3268: The primary reference "Microsoft.Xna.Framework.Xact" could not be resolved because it has an indirect dependency on the framework assembly "Microsoft.VisualC, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v4.0,Profile=Client". To resolve this problem, either remove the reference "Microsoft.Xna.Framework.Xact" or retarget your application to a framework version which contains "Microsoft.VisualC, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".

编辑:好的,我删除了那些有问题的XNA程序集.原来我不需要它们.现在编译器回到了这个错误:

error CS0518: Predefined type 'System.Object' is not defined or imported

Compile complete -- 1 errors, 0 warnings

Answer 1

Visual Studio正在向您显示正确的程序集.您无法为Windows Phone 7选择.NET 4.0程序集,原因很简单,因为Windows Phone 7不运行.NET 4.0.

您看到的版本应该是这样的:

• Microsoft.Phone.* - 7.0.0.0
• Microsoft.XNA.* - 4.0.0.0
• mscorelib - 2.0.5.0
• 系统.* - 2.0.5.0