C# App.Config with array or list like data

Question

How to have array or list like information in app.config? I want user to be able to put as many IPs as possible (or as needed). My program would just take whatever specified in app.config. How to do this?

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="ip" value="x" />
    <add key="ip" value="y" />
    <add key="ip" value="z" />
    </appSettings>
</configuration>



public string ip = ConfigurationManager.AppSettings["ip"];

write your own configuration section. [Here's](http://haacked.com/archive/2007/03/12/custom-configuration-sections-in-3-easy-steps.aspx/) a start. [This one](http://www.codeproject.com/Articles/37776/Writing-a-complex-custom-configuration-section) shows you how to loop through them — Jonesopolis, May 06 '14 at 15:41
@Jonesy Or use the hassle-free `StringCollection` settings type... — Thorsten Dittmar, May 06 '14 at 15:51
Possible duplicate of [How to get a List collection of values from app.config in WPF?](https://stackoverflow.com/questions/1779117/how-to-get-a-liststring-collection-of-values-from-app-config-in-wpf) — Squazz, May 31 '18 at 12:10
See my answer here for a way to create your own configuration section: https://stackoverflow.com/a/33544322/1955317 — Squazz, May 31 '18 at 12:11

score 54 · Accepted Answer · edited May 06 '14 at 15:45

The easiest way would be a comma separated list in your App.config file. Of course you can write your own configuration section, but what is the point of doing that if it is just an array of strings, keep it simple.

<configuration>
  <appSettings>
    <add key="ips" value="z,x,d,e" />
  </appSettings>
</configuration>

public string[] ipArray = ConfigurationManager.AppSettings["ips"].Split(',');

Thorsten Dittmar · Answer 2 · 2015-11-09T06:25:55.420

20

You can set the type of a setting in the settings designer to StringCollection, which allows you to create a list of strings.

Screenshot

You can later access individual values as Properties.Settings.Default.MyCollection[x].

In the app.config file this looks as follows:

<setting name="MyCollection" serializeAs="Xml">
<value>
    <ArrayOfString xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
        <string>Value1</string>
        <string>Value2</string>
    </ArrayOfString>
</value>
</setting>

edited Nov 09 '15 at 06:25

answered May 06 '14 at 15:50

Thorsten Dittmar

55,956
8
91
139

When I try and call the setting using Properties.Settings.MyCollection[x], it says An object reference is required for the non-static field, method, or property? any ideas? – Max Carroll Nov 08 '15 at 21:43
ahh got it, something like "StringCollection someRegKeys = new Properties.Settings().RegKeys;" – Max Carroll Nov 08 '15 at 21:49
Am error in my answer. Must be `Properties.Settings.Default.xyz`. – Thorsten Dittmar Nov 09 '15 at 06:25
This is a nicer way to go than using string parsing. In the settings designer, use the '...' on the right of the Values field to edit the collection of strings. It gets converted to XML for you. – bluedog Jul 03 '18 at 21:44

score 11 · Answer 3 · answered Dec 16 '16 at 14:06

11

In App.config,

<add key="YOURKEY" value="a,b,c"/>

In C#,

STRING ARRAY:

string[] InFormOfStringArray = ConfigurationManager.AppSettings["YOURKEY"].Split(',').Select(s => s.Trim()).ToArray();

LIST :

 List<string> list = new List<string>(InFormOfStringArray);

answered Dec 16 '16 at 14:06

Divya

373
4
3

9

Why not use `.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);`? – stomy Apr 10 '18 at 23:06

C# App.Config with array or list like data

3 Answers3