DBNull.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / clr / src / BCL / System / DBNull.cs / 1305376 / DBNull.cs
                        

                        
                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 
////////////////////////////////////////////////////////////////////////////////
// Void 
//    This class represents a Missing Variant 
////////////////////////////////////////////////////////////////////////////////
namespace System { 

    using System;
    using System.Runtime.Remoting;
    using System.Runtime.Serialization; 
    using System.Security.Permissions;
[System.Runtime.InteropServices.ComVisible(true)] 
    [Serializable] 
    public sealed class DBNull : ISerializable, IConvertible {
 
        //Package private constructor
        private DBNull(){
        }
 
        private DBNull(SerializationInfo info, StreamingContext context) {
            throw new NotSupportedException(Environment.GetResourceString("NotSupported_DBNullSerial")); 
        } 

        public static readonly DBNull Value = new DBNull(); 

        [System.Security.SecurityCritical]
        public void GetObjectData(SerializationInfo info, StreamingContext context) {
            UnitySerializationHolder.GetUnitySerializationInfo(info, UnitySerializationHolder.NullUnity, null, null); 
        }
 
        public override String ToString() { 
            return String.Empty;
        } 

        public String ToString(IFormatProvider provider) {
            return String.Empty;
        } 

        public TypeCode GetTypeCode() { 
            return TypeCode.DBNull; 
        }
 
        /// 
        bool IConvertible.ToBoolean(IFormatProvider provider) {
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
        } 

        ///  
        char IConvertible.ToChar(IFormatProvider provider) { 
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
        } 

        /// 
        sbyte IConvertible.ToSByte(IFormatProvider provider) {
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull")); 
        }
 
        ///  
        byte IConvertible.ToByte(IFormatProvider provider) {
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull")); 
        }

        /// 
        short IConvertible.ToInt16(IFormatProvider provider) { 
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
        } 
 
        /// 
        ushort IConvertible.ToUInt16(IFormatProvider provider) { 
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
        }

        ///  
        int IConvertible.ToInt32(IFormatProvider provider) {
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull")); 
        } 

        ///  
        uint IConvertible.ToUInt32(IFormatProvider provider) {
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
        }
 
        /// 
        long IConvertible.ToInt64(IFormatProvider provider) { 
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull")); 
        }
 
        /// 
        ulong IConvertible.ToUInt64(IFormatProvider provider) {
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
        } 

        ///  
        float IConvertible.ToSingle(IFormatProvider provider) { 
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
        } 

        /// 
        double IConvertible.ToDouble(IFormatProvider provider) {
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull")); 
        }
 
        ///  
        decimal IConvertible.ToDecimal(IFormatProvider provider) {
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull")); 
        }

        /// 
        DateTime IConvertible.ToDateTime(IFormatProvider provider) { 
            throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
        } 
 
        /// 
        Object IConvertible.ToType(Type type, IFormatProvider provider) { 
            return Convert.DefaultToType((IConvertible)this, type, provider);
        }
    }
} 


// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

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