Custom Configuration Settings in app.config

[tfowler]

I spent almost an entire day figuring out how to use custom configuration settings in an app.config.:mad: I never really found any good examples of how it should be done:( , so I decided to share what I learned here.:D

 

You can always store key/value pairs in the app.config file and read them using the AppSettings function. However, what if you have a more complicated situation where you need to group settings. That is where a custom configuration comes in. Note: you can always create your own XML settings file, but I like having a single place for all of the application settings.

 

So, say I have 3 different kinds of "things" that have 3 different properties that I want to retrieve.

 

I set up my app.config file as follows:

[size=2][color=#0000ff]<?[/color][/size][size=2][color=#a31515]xml[/color][/size][size=2][color=#ff0000]version[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]1.0[/color][/size][size=2]"[/size][size=2][color=#ff0000]encoding[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]utf-8[/color][/size][size=2]"[/size][size=2][color=#0000ff] ?>[/color][/size]
[size=2][color=#0000ff] <[/color][/size][size=2][color=#a31515]configuration[/color][/size][size=2][color=#0000ff]>[/color][/size]

[size=2][color=#0000ff][size=2][color=#0000ff]     <!--[/color][/size]
[size=2][color=#008000]     define the custom section[/color][/size]

[size=2][color=#008000]     note that the 'type' is full name for the class that will be used to access[/color][/size]
[size=2][color=#008000]     the custom section and the namespace. We will define this class later[/color][/size]
[size=2][color=#0000ff]     -->[/color][/size]
[/color][/size][size=2][color=#0000ff]     <[/color][/size][size=2][color=#a31515]configSections[/color][/size][size=2][color=#0000ff]>[/color][/size]
[size=2][color=#0000ff]         <[/color][/size][size=2][color=#a31515]section [/color][/size][size=2][color=#ff0000]name[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]SomeCustomSettings[/color][/size][size=2]"[/size]
[size=2][color=#ff0000]                     type[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]ConfigurationExample.SomeCustomSettingsSection, [/color][/size]
[size=2][color=#0000ff]                     ConfigurationExample[/color][/size][size=2]"[/size][size=2][color=#0000ff]/>[/color][/size]
[size=2][color=#0000ff]     </[/color][/size][size=2][color=#a31515]configSections[/color][/size][size=2][color=#0000ff]>[/color][/size]

[size=2][color=#0000ff]     <!--[/color][/size][size=2][color=#008000] here is the start of our custom configuration settings section [/color][/size][size=2][color=#0000ff]-->[/color][/size]
[size=2][color=#0000ff]     <[/color][/size][size=2][color=#a31515]SomeCustomSettings[/color][/size][size=2][color=#0000ff]> <!--[/color][/size][size=2][color=#008000] this is the ConfigurationSection [/color][/size][size=2][color=#0000ff]-->[/color][/size]
[size=2][color=#0000ff]         <[/color][/size][size=2][color=#a31515]things[/color][/size][size=2][color=#0000ff]> <!--[/color][/size][size=2][color=#008000] this is the ConfigurationElementCollection [/color][/size][size=2][color=#0000ff]-->[/color][/size]

[size=2][color=#0000ff]             <!--[/color][/size][size=2][color=#008000] these are the ConfigurationElements [/color][/size][size=2][color=#0000ff]-->[/color][/size]
[size=2][color=#0000ff]             <[/color][/size][size=2][color=#a31515]add [/color][/size][size=2][color=#ff0000]name[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]Thing1[/color][/size][size=2]"[/size]
[size=2][color=#ff0000]                    property1[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]Thing1's property1[/color][/size][size=2]"[/size]
[size=2][color=#ff0000]                    property2[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]100[/color][/size][size=2]"[/size]
[size=2][color=#ff0000]                    property3[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]Thing1's property3[/color][/size][size=2]"[/size]
[size=2][color=#0000ff]             />[/color][/size]
[size=2][color=#0000ff]             <[/color][/size][size=2][color=#a31515]add [/color][/size][size=2][color=#ff0000]name[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]Thing2[/color][/size][size=2]"[/size]
[size=2][color=#ff0000]                    property1[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]Thing2's property1[/color][/size][size=2]"[/size]
[size=2][color=#ff0000]                    property3[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]Thing2's property3[/color][/size][size=2]"[/size]
[size=2][color=#0000ff]             />[/color][/size]
[size=2][color=#0000ff]             <[/color][/size][size=2][color=#a31515]add [/color][/size][size=2][color=#ff0000]name[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]AnotherThing[/color][/size][size=2]"[/size]
[size=2][color=#ff0000]                    property1[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]Thing3's property1[/color][/size][size=2]"[/size]
[size=2][color=#ff0000]                    property2[/color][/size][size=2][color=#0000ff]=[/color][/size][size=2]"[/size][size=2][color=#0000ff]200[/color][/size][size=2]"[/size]
[size=2][color=#0000ff]              />[/color][/size]
[size=2][color=#0000ff]         </[/color][/size][size=2][color=#a31515]things[/color][/size][size=2][color=#0000ff]>[/color][/size]
[size=2][color=#0000ff]     </[/color][/size][size=2][color=#a31515]SomeCustomSettings[/color][/size][size=2][color=#0000ff]>[/color][/size]

[size=2][color=#0000ff] </[/color][/size][size=2][color=#a31515]configuration[/color][/size][size=2][color=#0000ff]>[/color][/size]

 

I now need to create classes to access this information.

 

See the attached files for the complete example (since we are limited a paltry 10000 characters :mad: ).

 

Hope this example helps someone. I tried to make it much clearer than any of the MSDN documentation or other examples that I found. Let me know if there is anything that I should modify to improve clarity, or if anyone has any questions.

 

Todd

ConfigurationExample.zip

Edited January 8, 2007 by tfowler