mcs/class/System/System.ComponentModel/BaseNumberConverter.cs

   1 //
   2 // System.ComponentModel.BaseNumberConverter.cs
   3 //
   4 // Authors:
   5 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   6 //
   7 // (C) 2002/2003 Ximian, Inc (http://www.ximian.com)
   8 // (C) 2003 Andreas Nahr
   9 //
  10
  11 using System;
  12 using System.Globalization;
  13
  14 namespace System.ComponentModel
  15 {
  16         public abstract class BaseNumberConverter : TypeConverter
  17         {
  18
  19                 internal Type InnerType;
  20
  21                 protected BaseNumberConverter()
  22                 {
  23                 }
  24
  25                 public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
  26                 {
  27                         if (sourceType == typeof (string))
  28                         return true;
  29                         return base.CanConvertFrom (context, sourceType);
  30                 }
  31
  32                 public override bool CanConvertTo(ITypeDescriptorContext context, Type t)
  33                 {
  34                         if (t == typeof (string))
  35                                 return true;
  36
  37                         return base.CanConvertTo (context, t);
  38                 }
  39
  40                 public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
  41                 {
  42                         if (value.GetType() == typeof (string)) {
  43                                 try {
  44                                         return Convert.ChangeType (value, InnerType, culture.NumberFormat);
  45                                 } catch (Exception e) {
  46                                         // LAMESPEC MS just seems to pass the internal Exception on to the user
  47                                         // so it throws a pure Exception here. We should probably throw a
  48                                         // ArgumentException or something like that
  49                                         throw e;
  50                                 }
  51                         }
  52
  53                         return base.ConvertFrom (context, culture, value);
  54                 }
  55
  56                 public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture,
  57                                                  object value, Type destinationType)
  58                 {
  59                         if (value == null)
  60                                 throw new ArgumentNullException ("value");
  61
  62                         if (destinationType == typeof (string) && value.GetType() == InnerType)
  63                                 return Convert.ChangeType (value, typeof (string), culture.NumberFormat);
  64
  65                         return base.ConvertTo (context, culture, value, destinationType);
  66                 }
  67         }
  68 }
  69