How to get a List<string> collection of values from app.config in WPF?

Question

The following example fills the ItemsControl with a List of BackupDirectories which I get from code.

How can I change this so that I get the same information from the app.config file?

XAML:

<Window x:Class="TestReadMultipler2343.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300">
    <Grid Margin="10">
        <Grid.RowDefinitions>
            <RowDefinition Height="30"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="120"/>
            <ColumnDefinition Width="160"/>
        </Grid.ColumnDefinitions>
        <TextBlock 
            Grid.Row="0"
            Grid.Column="0"
            Text="Title:"/>
        <TextBlock 
            Grid.Row="0"
            Grid.Column="1" 
            Text="{Binding Title}"/>
        <TextBlock 
            Grid.Row="1"
            Grid.Column="0"
            Text="Backup Directories:"/>
        <ItemsControl 
            Grid.Row="1"
            Grid.Column="1"
            ItemsSource="{Binding BackupDirectories}"/>
    </Grid>
</Window>

code-behind:

using System.Collections.Generic;
using System.Windows;
using System.Configuration;
using System.ComponentModel;

namespace TestReadMultipler2343
{
    public partial class Window1 : Window, INotifyPropertyChanged
    {

        #region ViewModelProperty: Title
        private string _title;
        public string Title
        {
            get
            {
                return _title;
            }

            set
            {
                _title = value;
                OnPropertyChanged("Title");
            }
        }
        #endregion

        #region ViewModelProperty: BackupDirectories
        private List<string> _backupDirectories = new List<string>();
        public List<string> BackupDirectories
        {
            get
            {
                return _backupDirectories;
            }

            set
            {
                _backupDirectories = value;
                OnPropertyChanged("BackupDirectories");
            }
        }
        #endregion

        public Window1()
        {
            InitializeComponent();
            DataContext = this;

            Title = ConfigurationManager.AppSettings.Get("title");

            GetBackupDirectoriesInternal();
        }

        void GetBackupDirectoriesInternal()
        {
            BackupDirectories.Add(@"C:\test1");
            BackupDirectories.Add(@"C:\test2");
            BackupDirectories.Add(@"C:\test3");
            BackupDirectories.Add(@"C:\test4");
        }

        void GetBackupDirectoriesFromConfig()
        {
            //BackupDirectories = ConfigurationManager.AppSettings.GetValues("backupDirectories");
        }


        #region INotifiedProperty Block
        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;

            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion

    }
}

app.config:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="title" value="Backup Tool" />
    <!--<add key="backupDirectories">
      <add value="C:\test1"/>
      <add value="C:\test2"/>
      <add value="C:\test3"/>
      <add value="C:\test4"/>
    </add>-->
  </appSettings>
</configuration>

Answer 1

You could have them semi-colon delimited in a single value, e.g.

App.config

<add key="paths" value="C:\test1;C:\test2;C:\test3" />

C#

var paths = new List<string>(ConfigurationManager.AppSettings["paths"].Split(new char[] { ';' }));