Settings in VS 2005

Settings can represent user preferences, or valuable information the application needs to use. For example, you might create a series of settings that store user preferences for the color scheme of an application. Or you might store the connection string that specifies a database that your application uses. Settings allow you to both persist information that is critical to the application outside of the code, and to create profiles that store the preferences of individual users.

In C# use settings by accessing the Properties namespace. In the course of this article, you will learn the difference between application and user settings, how to create new settings at design time, how to access settings at run time, and even how to incorporate multiple sets of settings into your application.


Application and User Settings
Settings have four properties:

Name: The Name property of settings is the name that is used to access the value of the setting at run time.
Type: The Type of the setting is the .NET Framework type that the setting represents. A setting can be of any type. For example, a setting that holds a user preference of color would be a System.Color type.
Scope: The Scope property represents how a setting can be accessed at run time. There are two possible values for the Scope property: Application and User. These will be discussed more in this section.
Value: The Value property represents the value returned when the setting is accessed. The value will be of the type represented by the Type property.

The crucial distinction between application-scope and user-scope settings is that user-scope settings are read/write at run time, and their values can be changed and saved in code. Application-scope settings are read only at run time. While they can be read, they cannot be written to. Settings with application scope can only be changed at design time, or by altering the settings file manually

Creating a New Setting at Design Time
You can create a new setting at design time by using the Settings designer. The Settings designer is a familiar grid-style interface that allows you to create new settings and specify properties for those settings. You must specify Name, Type, Scope, and Value for each new setting. Once a setting is created, it can be assessed in code using the mechanisms described later in this article.

To Create a New Setting at Design Time
1. In Solution Explorer, expand the Properties node of your project.
2. In Solution Explorer, double-click the .settings file in which you want to add a new setting. The default name for this file is Settings.settings.
3. In the Settings designer, set the Name, Type, Scope, and Value for your setting. Each row represents a single setting. Figure 1 shows an example of the Settings designer.

To Change the Value of a Setting Between Application Sessions

Using Microsoft Notepad or some other text or XML editor, open the .exe.config file associated with your application.
Locate the entry for the setting you want to change. It should look similar to the following example:

This is the setting value


Type a new value for your setting and save the file.