App.config: User vs Application Scope

Question

I have added App.config file in my project. I have created two settings from Project > Properties > Settings panel -

I have noticed that when I am adding a setting, I can define scope as User or Application. -

1. User
2. Application

If I define setting as User it goes touserSettings section,
if I define setting as Application it goes to applicationSettings section

App.config

<configuration>

    <userSettings>
        <DemoApp.Properties.Settings>
            <setting name="MySetting1" serializeAs="String">
                <value>Value1</value>
            </setting>
        </DemoApp.Properties.Settings>
    </userSettings>

    <applicationSettings>
        <DemoApp.Properties.Settings>
            <setting name="MySetting2" serializeAs="String">
                <value>Value2</value>
            </setting>
        </DemoApp.Properties.Settings>
    </applicationSettings>

</configuration>

But, these settings can be accessed in the same way from .cs -

Code

string mySetting1 = DemoApp.Properties.Settings.Default.MySetting1;
string mySetting2 = DemoApp.Properties.Settings.Default.MySetting2;

What is the difference between User and Application scope and under what circumstances one should choose between these two?

Answer 1

Basically, application settings cannot be changed during the running of a program and user settings can. These user settings should then be saved so the user is presented with a familiar experience when (s)he runs the application next.

Edit: For examples, you might write your application with different modules, and need to ensure that your main module is using the correct version of your security module. For this you would set up an application-scope setting eg:

SecurityModuleVersion  string     Application      v1.21

Sometime later when you refactor the security module, you might change the value to v1.22 when you deploy to ensure the correct security is being implemented

On the other hand, if your application has different 'skins' with color changes, font changes etc, then you may setup a user setting something like the following:

ApplicationSkin        string     User              DefaultSkin

Then, when Michelle changes to the skin she prefers, the application remembers her settings. The properties may now look like:

ApplicationSkin        string     User              HelloKittySkin