尝试从App.config文件获取字符串

Question

I'm desperately trying to make a working app.config file in which I want to save the connection strings for my database connections.

This is my app.config file:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="Con" value="User Id = *******;password=**;data source=  (DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = ******)(PORT = 1525))(CONNECT_DATA =(SERVER = DEDICATED)(SID = emtst)))"/>
  </appSettings>
</configuration>

And when I try to read it here:

  string connStr = ConfigurationManager.AppSettings["Con"];
  this.odacManager = new ODACManager(connStr);

I just get an empty string. I'm using System.Configuration .

I've also tried to use

ConfigurationManager.Connectionstring["Con"].ConnectionString

but that also didn't work.

Answer 1

You should be using the <connectionStrings> element in your config file:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
   <connectionStrings>
       <add name="Con" 
            connectionString="User Id=*******;password=**;data source=(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = ******)(PORT = 1525))(CONNECT_DATA =(SERVER = DEDICATED)(SID = emtst)))"/>
   </connectionStrings>
</configuration>

and then read it out as:

string connStr = ConfigurationManager.ConnectionStrings["Con"].ConnectionString;

Update:

In .NET, class library projects cannot have their own config files - they won't be used and won't be evaluated at runtime.

If your class library needs any configuration, you need to put that configuration into the host application's app.config (or web.config ) so that the class library can find it there (and use it).

Answer 2

尝试

System.Configuration.ConfigurationSettings.AppSettings["Con"].ToString();