Connectionstring in app.config

In the line
string connectionstr = ConfigurationManager.ConnectionStrings["ConnectionString1"].ConnectionString;

that ConnectionString1 is ConnectionString.

And the Exception I am getting is
"Object Reference Not set to an instance of the object"

I  tried changing this,
string connectionstr = ConfigurationManager.ConnectionStrings["ConnectionString1"].ToString();

But still getting same exception.

string connectionstr = ConfigurationManager.ConnectionString.["MyConnection"].ConnectionString;

<configuration>
  <connectionStrings>
    <add name="MyConnection" connectionString="this is a test"/>
  </connectionStrings>
</configuration>
                                              

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Thanks gauthampj, it works in normal application but in shared add-in where all my code is in Connect.cs file
I am still getting the same exception.What could be the reason?

Hi johny_bravo1,
I don't think that is the best way to go with storing connection strings, a safer way would be to hard code the connection string.

Here is the code to do it, just create a static class and call it whenever you need the connection string:

    static class Connection
    {
        public static SqlConnection conn()
        {
            return new SqlConnection("Data Source=192.168.40.46;Initial Catalog=Spot;Persist Security Info=True;User ID=sa;Password=sqlad;Min Pool Size=05;Max Pool Size=160;Connection Timeout = 250");
        }
    }
 
//To get the connection string from another class or form simply call it using the following line of code.
 
SqlConnection conn = Connection.conn();

                                              

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Hi there.

I just used the name 'MyConnectionString' in the code as an example, but to copy your code, you should rename this:

<configuration>
    <connectionStrings>
           <add name="MyConnection" connectionString="this is a test"/>
    </connectionStrings>
</configuration>

to this:

<configuration>
    <connectionStrings>
           <add name="ConnectionString" connectionString="Data Source=192.168.40.46;Initial Catalog=Spot;Persist Security Info=True;User ID=sa;Password=sqlad;Min Pool Size=05;Max Pool Size=160;Connection Timeout = 250"/>
    </connectionStrings>
</configuration>  

As per gauthampj's advice.

Cheers

Jas.

Hi.

In response to t0ni's comment, the best way to store the connection string is to encrypt it in the config file. Here's a link that explains this:

http://www.4guysfromrolla.com/articles/021506-1.aspx

Having the connection string in the code is suicide unless the code is obfuscated, since using .NET Reflector would allow anyone to view the code for the app and get the connection string details.

Also storing the connection string in the app.config file unencrypted is risky, since anyone can open the file in the Notepad and have a look.

Cheers.
Jas.

Thanks MrClyfar,
it's working in other applications but not here.

That's right MrClyfar, I didn't mean to say it's the best way to store sensitive data, but it's by far safer than storing in config file unencrypted.

can u try this

<configuration>	
  <appSettings>
     <add key="ConnectionString" value="Data Source=192.168.40.46;Initial Catalog=Spot;Persist Security Info=True;User ID=sa;Password=sqlad;Min Pool Size=05;Max Pool Size=160;Connection Timeout = 250" />
</appSettings>
</configuration>
 
string connectionstr = ConfigurationSettings.AppSettings["ConnectionString1"];
                                              

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I just need to clear this again that I am developing a Shared add-in and I am still not able to read values any value from app.config.
It's working getting it through class but I need to get it from config file.

Thanks gauthampj, already tried with it.

how are u testing the add in ?  are u installing it with a installer package ? if the app.config file is copied to the insatall directore i think it shud work no matter what

Hi there.

The app.config way of reading the config should work, if it;s not, then I also think that the app.config is in the wrong folder and your code cannot find it.

One other way to get around this is to put your connection string in the machine.config file. I have to go now, but here is a link that explains how to use machine.config:

http://msdn.microsoft.com/en-us/library/ms229697.aspx

http://forums.asp.net/p/1117776/1736929.aspx

Cheers.
Jas.

Yes te app.config was not installed on the machine when I set up installer package.
Now I added app.config to setup folder.
But still the error is there?

name shud be urdllname.config not app.config

You mean where my dll is copied there shud b urdllname.config file instead of app.config

s..

I renamed app.config as urdllname and copied it physically to installation folder but it is still throwing exception

:-( wierd..what is the name of the ur dll/project  and that of the  app config file ?

it is 'TestAddIn" and now as u said config is TestAddin.config

any  other idea?

what is the best way of putting connectionstring when I will install that add-in on client machine?

u can store as an encrypted string in the app.config file or in a registry value; if u are going to use app.config file then u will have to use the class i posted above to read the values

I have created a new class named ConfigurationSettings.
I have made little modification to it.
as my app.config looks like
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
      <connectionStrings>
            <add name="MyConnection" connectionString="coneection to database"/>

      </connectionStrings>
</configuration>
Now what next?

using System;
using System.Collections.Generic;
using System.Text;
 
namespace TestAddin
{
    public class ConfigurationSettings
    {
        public static NameValueCollection AppSettings;
 
        public static void LoadConfig()
        {
            try
            {
 
                string AppPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().GetName().CodeBase);
                string ConfigFile = Path.Combine(AppPath, "App.config");
 
                if (File.Exists(ConfigFile) == false)
                {
                    System.Windows.Forms.MessageBox.Show("Config file does not exist");
                    Application.Exit();
                    return;
                }
 
                XmlDocument oXml = new XmlDocument();
 
                oXml.Load(ConfigFile);
 
                XmlNodeList oList = oXml.GetElementsByTagName("connectionStrings");
 
                AppSettings = new NameValueCollection();
 
                foreach (XmlNode oNode in oList)
                {
                    foreach (XmlNode oKey in oNode.ChildNodes)
                    {
                        AppSettings.Add(oKey.Attributes["name"].Value, oKey.Attributes["connectionString"].Value);
                    }
                }
 
                System.Windows.Forms.MessageBox.Show(ConfigurationSettings.AppSettings["Item1"]);
 
            }
            catch (Exception) { throw; }
        }
 
 
    }
}
                                              

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u can access the information in app.config as ConfigurationSettings.AppSettings ["MyConnection"]; the file name of the app config file shud be "urdllName.dll.App.config"

Ok according to you I just need to implement that class exactly as it is.Create a config file with my dllname.dll.App.Config
and access the Appsetting in code.
That's it.

I will work on it tomorrow and inform you about it.
Let me know if I need to know something to get it work.
Thanks.Have a nice day :)

In ur class code I am getting error for 'Path' and 'Assembly'

what is the error ?

'Path' / 'Assembly' does not exist in current context

ok that error is resolved now.let me try after installing it.
The config file should be named as mydllname.dll.App.config.Right?

I chaged my app.config file to TestAddin.dll.App.config and set its properties Build Action=Compile,
Copy To Output Directory=Always.
Now it is throwing error for it.
A namespace doesnot directly contain members such as fields or methods.
:(

build action shud be content