class/System/System.ComponentModel/DefaultValueAttribute.cs

   1 //
   2 // System.ComponentModel.DefaultValueAttribute.cs
   3 //
   4 // Authors:
   5 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   6 //
   7 // (C) 2003 Andreas Nahr
   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.Globalization;
  32 namespace System.ComponentModel
  33 {
  34         [AttributeUsage(AttributeTargets.All)]
  35         public
  36 #if !NET_2_0
  37         sealed
  38 #endif
  39         class DefaultValueAttribute : Attribute
  40         {
  41
  42                 private object DefaultValue;
  43
  44                 public DefaultValueAttribute (bool value)
  45                 {
  46                         DefaultValue = value;
  47                 }
  48
  49                 public DefaultValueAttribute (byte value)
  50                 {
  51                         DefaultValue = value;
  52                 }
  53
  54                 public DefaultValueAttribute (char value)
  55                 {
  56                         DefaultValue = value;
  57                 }
  58
  59                 public DefaultValueAttribute (double value)
  60                 {
  61                         DefaultValue = value;
  62                 }
  63
  64                 public DefaultValueAttribute (short value)
  65                 {
  66                         DefaultValue = value;
  67                 }
  68
  69                 public DefaultValueAttribute (int value)
  70                 {
  71                         DefaultValue = value;
  72                 }
  73
  74                 public DefaultValueAttribute (long value)
  75                 {
  76                         DefaultValue = value;
  77                 }
  78
  79                 public DefaultValueAttribute (object value)
  80                 {
  81                         DefaultValue = value;
  82                 }
  83
  84                 public DefaultValueAttribute (float value)
  85                 {
  86                         DefaultValue = value;
  87                 }
  88
  89                 public DefaultValueAttribute (string value)
  90                 {
  91                         DefaultValue = value;
  92                 }
  93
  94                 public DefaultValueAttribute (Type type, string value)
  95                 {
  96                         try {
  97 #if NET_2_1
  98                                 if (type.IsEnum)
  99                                         DefaultValue = Enum.Parse (type, value);
 100                                 else if (type == typeof (TimeSpan))
 101                                         DefaultValue = TimeSpan.Parse (value);
 102                                 else
 103                                         DefaultValue = Convert.ChangeType (value, type, null);
 104 #else
 105                                 TypeConverter converter = TypeDescriptor.GetConverter (type);
 106                                 DefaultValue = converter.ConvertFromString (null, CultureInfo.InvariantCulture, value);
 107 #endif
 108                         } catch { }
 109                 }
 110
 111 #if NET_2_0
 112                 public virtual object Value {
 113 #else
 114                 public object Value {
 115 #endif
 116                         get { return DefaultValue; }
 117                 }
 118
 119 #if NET_2_0
 120                 protected void SetValue (object value)
 121                 {
 122                         DefaultValue = value;
 123                 }
 124 #endif
 125
 126                 public override bool Equals (object obj)
 127                 {
 128                         DefaultValueAttribute dva = (obj as DefaultValueAttribute);
 129                         if (dva == null)
 130                                 return false;
 131
 132                         if (DefaultValue == null)
 133                                 return (dva.Value == null);
 134
 135                         return DefaultValue.Equals (dva.Value);
 136                 }
 137
 138                 public override int GetHashCode()
 139                 {
 140                         if (DefaultValue == null)
 141                                 return base.GetHashCode ();
 142                         return DefaultValue.GetHashCode();
 143                 }
 144         }
 145 }