124 lines
4.4 KiB
C#
124 lines
4.4 KiB
C#
// ==++==
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//
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// Copyright (c) Microsoft Corporation. All rights reserved.
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//
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// ==--==
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////////////////////////////////////////////////////////////////////////////////
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// Void
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// This class represents a Missing Variant
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////////////////////////////////////////////////////////////////////////////////
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namespace System {
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using System;
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using System.Runtime.Remoting;
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using System.Runtime.Serialization;
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using System.Security.Permissions;
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[System.Runtime.InteropServices.ComVisible(true)]
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[Serializable]
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public sealed class DBNull : ISerializable, IConvertible {
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//Package private constructor
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private DBNull(){
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}
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private DBNull(SerializationInfo info, StreamingContext context) {
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throw new NotSupportedException(Environment.GetResourceString("NotSupported_DBNullSerial"));
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}
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public static readonly DBNull Value = new DBNull();
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[System.Security.SecurityCritical]
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public void GetObjectData(SerializationInfo info, StreamingContext context) {
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UnitySerializationHolder.GetUnitySerializationInfo(info, UnitySerializationHolder.NullUnity, null, null);
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}
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public override String ToString() {
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return String.Empty;
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}
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public String ToString(IFormatProvider provider) {
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return String.Empty;
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}
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public TypeCode GetTypeCode() {
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return TypeCode.DBNull;
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}
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/// <internalonly/>
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bool IConvertible.ToBoolean(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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char IConvertible.ToChar(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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sbyte IConvertible.ToSByte(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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byte IConvertible.ToByte(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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short IConvertible.ToInt16(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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ushort IConvertible.ToUInt16(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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int IConvertible.ToInt32(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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uint IConvertible.ToUInt32(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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long IConvertible.ToInt64(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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ulong IConvertible.ToUInt64(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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float IConvertible.ToSingle(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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double IConvertible.ToDouble(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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decimal IConvertible.ToDecimal(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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DateTime IConvertible.ToDateTime(IFormatProvider provider) {
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throw new InvalidCastException(Environment.GetResourceString("InvalidCast_FromDBNull"));
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}
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/// <internalonly/>
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Object IConvertible.ToType(Type type, IFormatProvider provider) {
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return Convert.DefaultToType((IConvertible)this, type, provider);
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}
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}
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}
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