netcore/System.Private.CoreLib/shared/System/DBNull.cs

   1 // Licensed to the .NET Foundation under one or more agreements.
   2 // The .NET Foundation licenses this file to you under the MIT license.
   3 // See the LICENSE file in the project root for more information.
   4
   5 using System.Runtime.Serialization;
   6
   7 namespace System
   8 {
   9     [Serializable]
  10     public sealed class DBNull : ISerializable, IConvertible
  11     {
  12         private DBNull()
  13         {
  14         }
  15
  16         private DBNull(SerializationInfo info, StreamingContext context)
  17         {
  18             throw new NotSupportedException(SR.NotSupported_DBNullSerial);
  19         }
  20
  21         public static readonly DBNull Value = new DBNull();
  22
  23         public void GetObjectData(SerializationInfo info, StreamingContext context)
  24         {
  25             UnitySerializationHolder.GetUnitySerializationInfo(info, UnitySerializationHolder.NullUnity);
  26         }
  27
  28         public override string ToString()
  29         {
  30             return string.Empty;
  31         }
  32
  33         public string ToString(IFormatProvider? provider)
  34         {
  35             return string.Empty;
  36         }
  37
  38         public TypeCode GetTypeCode()
  39         {
  40             return TypeCode.DBNull;
  41         }
  42
  43         bool IConvertible.ToBoolean(IFormatProvider? provider)
  44         {
  45             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
  46         }
  47
  48         char IConvertible.ToChar(IFormatProvider? provider)
  49         {
  50             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
  51         }
  52
  53         sbyte IConvertible.ToSByte(IFormatProvider? provider)
  54         {
  55             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
  56         }
  57
  58         byte IConvertible.ToByte(IFormatProvider? provider)
  59         {
  60             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
  61         }
  62
  63         short IConvertible.ToInt16(IFormatProvider? provider)
  64         {
  65             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
  66         }
  67
  68         ushort IConvertible.ToUInt16(IFormatProvider? provider)
  69         {
  70             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
  71         }
  72
  73         int IConvertible.ToInt32(IFormatProvider? provider)
  74         {
  75             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
  76         }
  77
  78         uint IConvertible.ToUInt32(IFormatProvider? provider)
  79         {
  80             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
  81         }
  82
  83         long IConvertible.ToInt64(IFormatProvider? provider)
  84         {
  85             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
  86         }
  87
  88         ulong IConvertible.ToUInt64(IFormatProvider? provider)
  89         {
  90             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
  91         }
  92
  93         float IConvertible.ToSingle(IFormatProvider? provider)
  94         {
  95             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
  96         }
  97
  98         double IConvertible.ToDouble(IFormatProvider? provider)
  99         {
 100             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
 101         }
 102
 103         decimal IConvertible.ToDecimal(IFormatProvider? provider)
 104         {
 105             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
 106         }
 107
 108         DateTime IConvertible.ToDateTime(IFormatProvider? provider)
 109         {
 110             throw new InvalidCastException(SR.InvalidCast_FromDBNull);
 111         }
 112
 113         object IConvertible.ToType(Type type, IFormatProvider? provider)
 114         {
 115             return Convert.DefaultToType((IConvertible)this, type, provider);
 116         }
 117     }
 118 }