mcs/class/System/System.Configuration/AppSettingsReader.cs

   1 //
   2 // System.Configuration.AppSettingsReader
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 // (C) 2002 Ximian, Inc (http://www.ximian.com)
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System.Reflection;
  32 using System.Collections.Specialized;
  33
  34 namespace System.Configuration
  35 {
  36         public class AppSettingsReader
  37         {
  38                 NameValueCollection appSettings;
  39
  40                 public AppSettingsReader ()
  41                 {
  42                         appSettings = ConfigurationSettings.AppSettings;
  43                 }
  44
  45                 public object GetValue (string key, Type type)
  46                 {
  47                         if (key == null)
  48                                 throw new ArgumentNullException ("key");
  49
  50                         if (type == null)
  51                                 throw new ArgumentNullException ("type");
  52
  53                         string value = appSettings [key];
  54                         if (value == null)
  55                                 throw new InvalidOperationException ("'" + key + "' could not be found.");
  56
  57                         if (type == typeof (string))
  58                                 return value;
  59
  60                         MethodInfo parse = type.GetMethod ("Parse", new Type [] {typeof (string)});
  61                         if (parse == null)
  62                                 throw new InvalidOperationException ("Type " + type + " does not have a Parse method");
  63
  64                         object result = null;
  65                         try {
  66                                 result = parse.Invoke (null, new object [] {value});
  67                         } catch (Exception e) {
  68                                 throw new InvalidOperationException ("Parse error.", e);
  69                         }
  70
  71                         return result;
  72                 }
  73         }
  74 }
  75