Edward Tanguay Edward Tanguay - 4 months ago 32
C# Question

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

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

You can create your own custom config section in the app.config file. There are quite a few tutorials around to get you started. Ultimately, you could have something like this:

<configSections>
    <section name="backupDirectories" type="TestReadMultipler2343.BackupDirectoriesSection, TestReadMultipler2343" />
  </configSections>

<backupDirectories>
   <directory location="C:\test1" />
   <directory location="C:\test2" />
   <directory location="C:\test3" />
</backupDirectories>
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