CODEWITHSUNDEEP
c#asp.net
Steven
Steven

Reputation: 18869

Get connection string from app.config

I'm trying to make this simple call:

DataContext dc = new DataContext(ConfigurationManager.ConnectionStrings["MyDB"].ConnectionString)

And here's my app.config file:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <connectionStrings>
    <add name="MyDB" connectionString="Server=STEVEN-PC;Database=MyDB;Trusted_Connection=yes;" />
  </connectionStrings>
</configuration>

But I'm getting an error: Object reference not set to an instance of an object.

It can't find the connection string. What am I doing wrong?

Upvotes: 2

Views: 5171

Answers (3)

Brandon Montgomery
Brandon Montgomery

Reputation: 6986

You might need to specify the providerName:

<add name="MyDB" connectionString="Server=STEVEN-PC;Database=MyDB;Trusted_Connection=yes;" providerName="System.Data.SqlClient" />

Upvotes: 0

Jacob
Jacob

Reputation: 78910

A common mistake is trying to read a connection string from an app.config from a referenced project instead of from the executable project (the web site or .exe project). You may need to copy the config settings containing the connection string to your main config file.

Upvotes: 15

Josh
Josh

Reputation: 69282

Double check the existence and contents of your configuration file in the build directory. That code should work fine if the config file is in place.

You could also pull put the connection string into a local variable so you can be sure the null reference exception is happening where you think it is.

Upvotes: 1

Related Questions