Visual Studio 2010中不存在System.Data

Question

I have a red line under System.Data saying that "The type or namespace 'Data' does not exist in the namespace 'System' (are you missing an assembly reference?)."

Thought I needed 4.5 .Net Framework, but I have another project that can use the namespace, so it is something with this project that I am using.

I have seen other threads similar to mine, such as this , but it isn't directly related to just system.data. It's trying to add a namespace beyond data, so there system.data namespace isn't the problem. Haven't seen any threads only related to just the system.data namespace. Any help would be appreciated.

Answer 1

did you try to add the assembly reference in your project? right click on your project > add reference then select assemblies tab and finally System.Data and check it, then press ok.

Answer 2

您是否检查过以确保对System.Data程序集的引用在您的项目中？

Answer 3

Have you a reference to syste.data under your references folder in solution explorer window? If not add it

Answer 4

check the project configuration :

 ->Right click on Project
 ->Select Properties
 ->Change  "Target Framework" from ".Net Framework 4.0 Client Profile" to ".Net Framework 4.0"
 ->now run the Project.