Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
437 views
in Technique[技术] by (71.8m points)

c# - ConnectionString from app.config of a DLL is null

I have a class library that contains a valid connectionString inside the app.config. Inside that class library I want to use it with

ConfigurationManager.ConnectionStrings["NAME"].ConnectionString

My ASP.net 4.0 framework application references that DDL and retrieves data from it. I want create a Entity Framework 4 DataContext within my DDL with the ConnectionString from the App.config. (I do not want to pass the connectionString from my ASP.net application in every single method. (I'm using ObjectDataSources))

However, this line inside my DLL throws a NullReferenceException.

ConfigurationManager.ConnectionStrings["NAME"].ConnectionString

How can I fix this issue?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

I have a class library that contains a valid connectionString inside the app.config

A class library doesn't have an app.config file associated. It's the application consuming this assembly that does. So you need to put the connection string inside this config file (if this is an ASP.NET application this would be web.config). Thus adding an App.config file in a project of type class library in Visual Studio makes no sense.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...