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// Declarations

/// <summary>
/// A property store
/// </summary>
[ComImport]
[Guid("886D8EEB-8CF2-4446-8D02-CDBA1DBDCF99")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
interface IPropertyStore
{
    /// <summary>
    /// Gets the number of properties contained in the property store.
    /// </summary>
    /// <param name="propertyCount"></param>
    /// <returns></returns>
    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime)]
    int GetCount([Out] out uint propertyCount);

	/// <summary>
    /// Get a property key located at a specific index.
    /// </summary>
    /// <param name="propertyIndex"></param>
    /// <param name="key"></param>
    /// <returns></returns>
    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime)]
    int GetAt([In] uint propertyIndex, out PropertyKey key);

    /// <summary>
    /// Gets the value of a property from the store
    /// </summary>
    /// <param name="key"></param>
    /// <param name="pv"></param>
    /// <returns></returns>
    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime)]
    int GetValue([In] ref PropertyKey key, [Out] PropVariant pv);

    /// <summary>
    /// Sets the value of a property in the store
    /// </summary>
    /// <param name="key"></param>
    /// <param name="pv"></param>
    /// <returns></returns>
    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime), PreserveSig]
    int SetValue([In] ref PropertyKey key, [In] PropVariant pv);

    /// <summary>
    /// Commits the changes.
    /// </summary>
    /// <returns></returns>
    [PreserveSig]
    [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType = MethodCodeType.Runtime)]
    int Commit();
}
	
/// <summary>
    /// Defines a unique key for a Shell Property
    /// </summary>
    [StructLayout(LayoutKind.Sequential, Pack = 4)]
    public struct PropertyKey : IEquatable<PropertyKey>
    {
        #region Private Fields

        private Guid formatId;
        private Int32 propertyId;

        #endregion

        #region Public Properties
        /// <summary>
        /// A unique GUID for the property
        /// </summary>
        public Guid FormatId
        {
            get
            {
                return formatId;
            }
        }

        /// <summary>
        ///  Property identifier (PID)
        /// </summary>
        public Int32 PropertyId
        {
            get
            {
                return propertyId;
            }
        }

        #endregion

        #region Public Construction

        /// <summary>
        /// PropertyKey Constructor
        /// </summary>
        /// <param name="formatId">A unique GUID for the property</param>
        /// <param name="propertyId">Property identifier (PID)</param>
        public PropertyKey(Guid formatId, Int32 propertyId)
        {
            this.formatId = formatId;
            this.propertyId = propertyId;
        }

        /// <summary>
        /// PropertyKey Constructor
        /// </summary>
        /// <param name="formatId">A string represenstion of a GUID for the property</param>
        /// <param name="propertyId">Property identifier (PID)</param>
        public PropertyKey(string formatId, Int32 propertyId)
        {
            this.formatId = new Guid(formatId);
            this.propertyId = propertyId;
        }

        #endregion

        #region IEquatable<PropertyKey> Members

        /// <summary>
        /// Returns whether this object is equal to another. This is vital for performance of value types.
        /// </summary>
        /// <param name="other">The object to compare against.</param>
        /// <returns>Equality result.</returns>
        public bool Equals(PropertyKey other)
        {
            return other.Equals((object)this);
        }

        #endregion

        #region equality and hashing

        /// <summary>
        /// Returns the hash code of the object. This is vital for performance of value types.
        /// </summary>
        /// <returns></returns>
        public override int GetHashCode()
        {
            return formatId.GetHashCode() ^ propertyId;
        }

        /// <summary>
        /// Returns whether this object is equal to another. This is vital for performance of value types.
        /// </summary>
        /// <param name="obj">The object to compare against.</param>
        /// <returns>Equality result.</returns>
        public override bool Equals(object obj)
        {
            if (obj == null)
                return false;

            if (!(obj is PropertyKey))
                return false;

            PropertyKey other = (PropertyKey)obj;
            return other.formatId.Equals(formatId) && (other.propertyId == propertyId);
        }

        /// <summary>
        /// Implements the == (equality) operator.
        /// </summary>
        /// <param name="propKey1">First property key to compare.</param>
        /// <param name="propKey2">Second property key to compare.</param>
        /// <returns>true if object a equals object b. false otherwise.</returns>        
        public static bool operator ==(PropertyKey propKey1, PropertyKey propKey2)
        {
            return propKey1.Equals(propKey2);
        }

        /// <summary>
        /// Implements the != (inequality) operator.
        /// </summary>
        /// <param name="propKey1">First property key to compare</param>
        /// <param name="propKey2">Second property key to compare.</param>
        /// <returns>true if object a does not equal object b. false otherwise.</returns>
        public static bool operator !=(PropertyKey propKey1, PropertyKey propKey2)
        {
            return !propKey1.Equals(propKey2);
        }

        /// <summary>
        /// Override ToString() to provide a user friendly string representation
        /// </summary>
        /// <returns>String representing the property key</returns>        
        public override string ToString()
        {
            return string.Format(System.Globalization.CultureInfo.InvariantCulture,
                "{0}, {1}",
                formatId.ToString("B"), propertyId);
        }

        #endregion
    }
	
	PropertyKey PKEY_EdgeGesture_DisableTouchWhenFullscreen = new PropertyKey("32CE38B2-2C9A-41B1-9BC5-B3784394AA44", 2);
	
	internal static class PropVariantNativeMethods
    {
        [DllImport("Ole32.dll", PreserveSig = false)] // returns hresult
        internal extern static void PropVariantClear([In, Out] PropVariant pvar);

        [DllImport("OleAut32.dll", PreserveSig = true)] // psa is actually returned, not hresult
        internal extern static IntPtr SafeArrayCreateVector(ushort vt, int lowerBound, uint cElems);

        [DllImport("OleAut32.dll", PreserveSig = false)] // returns hresult
        internal extern static IntPtr SafeArrayAccessData(IntPtr psa);

        [DllImport("OleAut32.dll", PreserveSig = false)] // returns hresult
        internal extern static void SafeArrayUnaccessData(IntPtr psa);

        [DllImport("OleAut32.dll", PreserveSig = true)] // retuns uint32
        internal extern static uint SafeArrayGetDim(IntPtr psa);

        [DllImport("OleAut32.dll", PreserveSig = false)] // returns hresult
        internal extern static int SafeArrayGetLBound(IntPtr psa, uint nDim);

        [DllImport("OleAut32.dll", PreserveSig = false)] // returns hresult
        internal extern static int SafeArrayGetUBound(IntPtr psa, uint nDim);

        // This decl for SafeArrayGetElement is only valid for cDims==1!
        [DllImport("OleAut32.dll", PreserveSig = false)] // returns hresult
        [return: MarshalAs(UnmanagedType.IUnknown)]
        internal extern static object SafeArrayGetElement(IntPtr psa, ref int rgIndices);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromPropVariantVectorElem([In] PropVariant propvarIn, uint iElem, [Out] PropVariant ppropvar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromFileTime([In] ref System.Runtime.InteropServices.ComTypes.FILETIME pftIn, [Out] PropVariant ppropvar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true)]
        [return: MarshalAs(UnmanagedType.I4)]
        internal static extern int PropVariantGetElementCount([In] PropVariant propVar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void PropVariantGetBooleanElem([In] PropVariant propVar, [In]uint iElem, [Out, MarshalAs(UnmanagedType.Bool)] out bool pfVal);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void PropVariantGetInt16Elem([In] PropVariant propVar, [In] uint iElem, [Out] out short pnVal);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void PropVariantGetUInt16Elem([In] PropVariant propVar, [In] uint iElem, [Out] out ushort pnVal);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void PropVariantGetInt32Elem([In] PropVariant propVar, [In] uint iElem, [Out] out int pnVal);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void PropVariantGetUInt32Elem([In] PropVariant propVar, [In] uint iElem, [Out] out uint pnVal);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void PropVariantGetInt64Elem([In] PropVariant propVar, [In] uint iElem, [Out] out Int64 pnVal);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void PropVariantGetUInt64Elem([In] PropVariant propVar, [In] uint iElem, [Out] out UInt64 pnVal);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void PropVariantGetDoubleElem([In] PropVariant propVar, [In] uint iElem, [Out] out double pnVal);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void PropVariantGetFileTimeElem([In] PropVariant propVar, [In] uint iElem, [Out, MarshalAs(UnmanagedType.Struct)] out System.Runtime.InteropServices.ComTypes.FILETIME pftVal);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void PropVariantGetStringElem([In] PropVariant propVar, [In]  uint iElem, [MarshalAs(UnmanagedType.LPWStr)] ref string ppszVal);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromBooleanVector([In, MarshalAs(UnmanagedType.LPArray)] bool[] prgf, uint cElems, [Out] PropVariant ppropvar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromInt16Vector([In, Out] Int16[] prgn, uint cElems, [Out] PropVariant ppropvar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromUInt16Vector([In, Out] UInt16[] prgn, uint cElems, [Out] PropVariant ppropvar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromInt32Vector([In, Out] Int32[] prgn, uint cElems, [Out] PropVariant propVar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromUInt32Vector([In, Out] UInt32[] prgn, uint cElems, [Out] PropVariant ppropvar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromInt64Vector([In, Out] Int64[] prgn, uint cElems, [Out] PropVariant ppropvar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromUInt64Vector([In, Out] UInt64[] prgn, uint cElems, [Out] PropVariant ppropvar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromDoubleVector([In, Out] double[] prgn, uint cElems, [Out] PropVariant propvar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromFileTimeVector([In, Out] System.Runtime.InteropServices.ComTypes.FILETIME[] prgft, uint cElems, [Out] PropVariant ppropvar);

        [DllImport("propsys.dll", CharSet = CharSet.Unicode, SetLastError = true, PreserveSig = false)]
        internal static extern void InitPropVariantFromStringVector([In, Out] string[] prgsz, uint cElems, [Out] PropVariant ppropvar);
    }
	
/// <summary>
    /// Represents the OLE struct PROPVARIANT.
    /// This class is intended for internal use only.
    /// </summary>
    /// <remarks>
    /// Originally sourced from http://blogs.msdn.com/adamroot/pages/interop-with-propvariants-in-net.aspx
    /// and modified to support additional types including vectors and ability to set values
    /// </remarks>
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Portability", "CA1900:ValueTypeFieldsShouldBePortable", MessageId = "_ptr2")]
    [StructLayout(LayoutKind.Explicit)]
    public sealed class PropVariant : IDisposable
    {
        #region Vector Action Cache

        // A static dictionary of delegates to get data from array's contained within PropVariants
        private static Dictionary<Type, Action<PropVariant, Array, uint>> _vectorActions = null;
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Maintainability", "CA1502:AvoidExcessiveComplexity")]
        private static Dictionary<Type, Action<PropVariant, Array, uint>> GenerateVectorActions()
        {
            Dictionary<Type, Action<PropVariant, Array, uint>> cache = new Dictionary<Type, Action<PropVariant, Array, uint>>();

            cache.Add(typeof(Int16), (pv, array, i) =>
            {
                short val;
                PropVariantNativeMethods.PropVariantGetInt16Elem(pv, i, out val);
                array.SetValue(val, i);
            });

            cache.Add(typeof(UInt16), (pv, array, i) =>
            {
                ushort val;
                PropVariantNativeMethods.PropVariantGetUInt16Elem(pv, i, out val);
                array.SetValue(val, i);
            });

            cache.Add(typeof(Int32), (pv, array, i) =>
            {
                int val;
                PropVariantNativeMethods.PropVariantGetInt32Elem(pv, i, out val);
                array.SetValue(val, i);
            });

            cache.Add(typeof(UInt32), (pv, array, i) =>
            {
                uint val;
                PropVariantNativeMethods.PropVariantGetUInt32Elem(pv, i, out val);
                array.SetValue(val, i);
            });

            cache.Add(typeof(Int64), (pv, array, i) =>
            {
                long val;
                PropVariantNativeMethods.PropVariantGetInt64Elem(pv, i, out val);
                array.SetValue(val, i);
            });

            cache.Add(typeof(UInt64), (pv, array, i) =>
            {
                ulong val;
                PropVariantNativeMethods.PropVariantGetUInt64Elem(pv, i, out val);
                array.SetValue(val, i);
            });

            cache.Add(typeof(DateTime), (pv, array, i) =>
            {
                System.Runtime.InteropServices.ComTypes.FILETIME val;
                PropVariantNativeMethods.PropVariantGetFileTimeElem(pv, i, out val);

                long fileTime = GetFileTimeAsLong(ref val);

                array.SetValue(DateTime.FromFileTime(fileTime), i);
            });

            cache.Add(typeof(Boolean), (pv, array, i) =>
            {
                bool val;
                PropVariantNativeMethods.PropVariantGetBooleanElem(pv, i, out val);
                array.SetValue(val, i);
            });

            cache.Add(typeof(Double), (pv, array, i) =>
            {
                double val;
                PropVariantNativeMethods.PropVariantGetDoubleElem(pv, i, out val);
                array.SetValue(val, i);
            });

            cache.Add(typeof(Single), (pv, array, i) => // float
            {                
                float[] val = new float[1];
                Marshal.Copy(pv._ptr2, val, (int)i, 1);
                array.SetValue(val[0], (int)i);
            });

            cache.Add(typeof(Decimal), (pv, array, i) =>
            {
                int[] val = new int[4];
                for (int a = 0; a < val.Length; a++)
                {
                    val[a] = Marshal.ReadInt32(pv._ptr2,
                        (int)i * sizeof(decimal) + a * sizeof(int)); //index * size + offset quarter
                }
                array.SetValue(new decimal(val), i);
            });

            cache.Add(typeof(String), (pv, array, i) =>
            {
                string val = string.Empty;
                PropVariantNativeMethods.PropVariantGetStringElem(pv, i, ref val);
                array.SetValue(val, i);
            });

            return cache;
        }
        #endregion

        #region Dynamic Construction / Factory (Expressions)

        /// <summary>
        /// Attempts to create a PropVariant by finding an appropriate constructor.
        /// </summary>
        /// <param name="value">Object from which PropVariant should be created.</param>
        public static PropVariant FromObject(object value)
        {
            if (value == null)
            {
                return new PropVariant();
            }
            else
            {
                var func = GetDynamicConstructor(value.GetType());
                return func(value);
            }
        }

        // A dictionary and lock to contain compiled expression trees for constructors
        private static Dictionary<Type, Func<object, PropVariant>> _cache = new Dictionary<Type, Func<object, PropVariant>>();
        private static object _padlock = new object();

        // Retrieves a cached constructor expression.
        // If no constructor has been cached, it attempts to find/add it.  If it cannot be found
        // an exception is thrown.
        // This method looks for a public constructor with the same parameter type as the object.
        private static Func<object, PropVariant> GetDynamicConstructor(Type type)
        {
            lock (_padlock)
            {
                // initial check, if action is found, return it
                Func<object, PropVariant> action;
                if (!_cache.TryGetValue(type, out action))
                {
                    // iterates through all constructors
                    ConstructorInfo constructor = typeof(PropVariant)
                        .GetConstructor(new Type[] { type });

                    if (constructor == null)
                    { // if the method was not found, throw.
                        throw new ArgumentException(LocalizedMessages.PropVariantTypeNotSupported);
                    }
                    else // if the method was found, create an expression to call it.
                    {
                        // create parameters to action                    
                        var arg = Expression.Parameter(typeof(object), "arg");

                        // create an expression to invoke the constructor with an argument cast to the correct type
                        var create = Expression.New(constructor, Expression.Convert(arg, type));

                        // compiles expression into an action delegate
                        action = Expression.Lambda<Func<object, PropVariant>>(create, arg).Compile();
                        _cache.Add(type, action);
                    }
                }
                return action;
            }
        }

        #endregion

        #region Fields

        [FieldOffset(0)]
        decimal _decimal;

        // This is actually a VarEnum value, but the VarEnum type
        // requires 4 bytes instead of the expected 2.
        [FieldOffset(0)]
        ushort _valueType;

        // Reserved Fields
        //[FieldOffset(2)]
        //ushort _wReserved1;
        //[FieldOffset(4)]
        //ushort _wReserved2;
        //[FieldOffset(6)]
        //ushort _wReserved3;

        // In order to allow x64 compat, we need to allow for
        // expansion of the IntPtr. However, the BLOB struct
        // uses a 4-byte int, followed by an IntPtr, so
        // although the valueData field catches most pointer values,
        // we need an additional 4-bytes to get the BLOB
        // pointer. The valueDataExt field provides this, as well as
        // the last 4-bytes of an 8-byte value on 32-bit
        // architectures.
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Reliability", "CA2006:UseSafeHandleToEncapsulateNativeResources")]
        [FieldOffset(12)]
        IntPtr _ptr2;
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Reliability", "CA2006:UseSafeHandleToEncapsulateNativeResources")]
        [FieldOffset(8)]
        IntPtr _ptr;
        [FieldOffset(8)]
        Int32 _int32;
        [FieldOffset(8)]
        UInt32 _uint32;
        [FieldOffset(8)]
        byte _byte;
        [FieldOffset(8)]
        sbyte _sbyte;
        [FieldOffset(8)]
        short _short;
        [FieldOffset(8)]
        ushort _ushort;
        [FieldOffset(8)]
        long _long;
        [FieldOffset(8)]
        ulong _ulong;
        [FieldOffset(8)]
        double _double;
        [FieldOffset(8)]
        float _float;

        #endregion // struct fields

        #region Constructors

        /// <summary>
        /// Default constrcutor
        /// </summary>
        public PropVariant()
        {
            // left empty
        }

        /// <summary>
        /// Set a string value
        /// </summary>
        public PropVariant(string value)
        {
            if (value == null)
            {
                throw new ArgumentException(LocalizedMessages.PropVariantNullString, "value");
            }

            _valueType = (ushort)VarEnum.VT_LPWSTR;
            _ptr = Marshal.StringToCoTaskMemUni(value);
        }

        /// <summary>
        /// Set a string vector
        /// </summary>
        public PropVariant(string[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }

            PropVariantNativeMethods.InitPropVariantFromStringVector(value, (uint)value.Length, this);
        }

        /// <summary>
        /// Set a bool vector
        /// </summary>
        public PropVariant(bool[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }

            PropVariantNativeMethods.InitPropVariantFromBooleanVector(value, (uint)value.Length, this);
        }

        /// <summary>
        /// Set a short vector
        /// </summary>
        public PropVariant(short[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }

            PropVariantNativeMethods.InitPropVariantFromInt16Vector(value, (uint)value.Length, this);
        }

        /// <summary>
        /// Set a short vector
        /// </summary>
        public PropVariant(ushort[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }

            PropVariantNativeMethods.InitPropVariantFromUInt16Vector(value, (uint)value.Length, this);

        }

        /// <summary>
        /// Set an int vector
        /// </summary>
        public PropVariant(int[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }

            PropVariantNativeMethods.InitPropVariantFromInt32Vector(value, (uint)value.Length, this);
        }

        /// <summary>
        /// Set an uint vector
        /// </summary>
        public PropVariant(uint[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }

            PropVariantNativeMethods.InitPropVariantFromUInt32Vector(value, (uint)value.Length, this);
        }

        /// <summary>
        /// Set a long vector
        /// </summary>
        public PropVariant(long[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }

            PropVariantNativeMethods.InitPropVariantFromInt64Vector(value, (uint)value.Length, this);
        }

        /// <summary>
        /// Set a ulong vector
        /// </summary>
        public PropVariant(ulong[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }

            PropVariantNativeMethods.InitPropVariantFromUInt64Vector(value, (uint)value.Length, this);
        }

        /// <summary>>
        /// Set a double vector
        /// </summary>
        public PropVariant(double[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }

            PropVariantNativeMethods.InitPropVariantFromDoubleVector(value, (uint)value.Length, this);
        }


        /// <summary>
        /// Set a DateTime vector
        /// </summary>
        public PropVariant(DateTime[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }
            System.Runtime.InteropServices.ComTypes.FILETIME[] fileTimeArr =
                new System.Runtime.InteropServices.ComTypes.FILETIME[value.Length];

            for (int i = 0; i < value.Length; i++)
            {
                fileTimeArr[i] = DateTimeToFileTime(value[i]);
            }

            PropVariantNativeMethods.InitPropVariantFromFileTimeVector(fileTimeArr, (uint)fileTimeArr.Length, this);
        }

        /// <summary>
        /// Set a bool value
        /// </summary>
        public PropVariant(bool value)
        {
            _valueType = (ushort)VarEnum.VT_BOOL;
            _int32 = (value == true) ? -1 : 0;
        }

        /// <summary>
        /// Set a DateTime value
        /// </summary>
        public PropVariant(DateTime value)
        {
            _valueType = (ushort)VarEnum.VT_FILETIME;

            System.Runtime.InteropServices.ComTypes.FILETIME ft = DateTimeToFileTime(value);
            PropVariantNativeMethods.InitPropVariantFromFileTime(ref ft, this);
        }


        /// <summary>
        /// Set a byte value
        /// </summary>
        public PropVariant(byte value)
        {
            _valueType = (ushort)VarEnum.VT_UI1;
            _byte = value;
        }

        /// <summary>
        /// Set a sbyte value
        /// </summary>
        public PropVariant(sbyte value)
        {
            _valueType = (ushort)VarEnum.VT_I1;
            _sbyte = value;
        }

        /// <summary>
        /// Set a short value
        /// </summary>
        public PropVariant(short value)
        {
            _valueType = (ushort)VarEnum.VT_I2;
            _short = value;
        }

        /// <summary>
        /// Set an unsigned short value
        /// </summary>
        public PropVariant(ushort value)
        {
            _valueType = (ushort)VarEnum.VT_UI2;
            _ushort = value;
        }

        /// <summary>
        /// Set an int value
        /// </summary>
        public PropVariant(int value)
        {
            _valueType = (ushort)VarEnum.VT_I4;
            _int32 = value;
        }

        /// <summary>
        /// Set an unsigned int value
        /// </summary>
        public PropVariant(uint value)
        {
            _valueType = (ushort)VarEnum.VT_UI4;
            _uint32 = value;
        }

        /// <summary>
        /// Set a decimal  value
        /// </summary>
        public PropVariant(decimal value)
        {
            _decimal = value;

            // It is critical that the value type be set after the decimal value, because they overlap.
            // If valuetype is written first, its value will be lost when _decimal is written.
            _valueType = (ushort)VarEnum.VT_DECIMAL;
        }

        /// <summary>
        /// Create a PropVariant with a contained decimal array.
        /// </summary>
        /// <param name="value">Decimal array to wrap.</param>
        public PropVariant(decimal[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }

            _valueType = (ushort)(VarEnum.VT_DECIMAL | VarEnum.VT_VECTOR);
            _int32 = value.Length;

            // allocate required memory for array with 128bit elements
            _ptr2 = Marshal.AllocCoTaskMem(value.Length * sizeof(decimal));            
            for (int i = 0; i < value.Length; i++)
            {                
                int[] bits = decimal.GetBits(value[i]);
                Marshal.Copy(bits, 0, _ptr2, bits.Length);
            }
        }

        /// <summary>
        /// Create a PropVariant containing a float type.
        /// </summary>        
        public PropVariant(float value)
        {
            _valueType = (ushort)VarEnum.VT_R4;

            _float = value;
        }

        /// <summary>
        /// Creates a PropVariant containing a float[] array.
        /// </summary>        
        public PropVariant(float[] value)
        {
            if (value == null) { throw new ArgumentNullException("value"); }

            _valueType = (ushort)(VarEnum.VT_R4 | VarEnum.VT_VECTOR);
            _int32 = value.Length;
                        
            _ptr2 = Marshal.AllocCoTaskMem(value.Length * sizeof(float));

            Marshal.Copy(value, 0, _ptr2, value.Length);
        }

        /// <summary>
        /// Set a long
        /// </summary>
        public PropVariant(long value)
        {
            _long = value;
            _valueType = (ushort)VarEnum.VT_I8;
        }

        /// <summary>
        /// Set a ulong
        /// </summary>
        public PropVariant(ulong value)
        {
            _valueType = (ushort)VarEnum.VT_UI8;
            _ulong = value;
        }

        /// <summary>
        /// Set a double
        /// </summary>
        public PropVariant(double value)
        {
            _valueType = (ushort)VarEnum.VT_R8;
            _double = value;
        }

        #endregion

        #region Uncalled methods - These are currently not called, but I think may be valid in the future.

        /// <summary>
        /// Set an IUnknown value
        /// </summary>
        /// <param name="value">The new value to set.</param>
        internal void SetIUnknown(object value)
        {
            _valueType = (ushort)VarEnum.VT_UNKNOWN;
            _ptr = Marshal.GetIUnknownForObject(value);
        }


        /// <summary>
        /// Set a safe array value
        /// </summary>
        /// <param name="array">The new value to set.</param>
        internal void SetSafeArray(Array array)
        {
            if (array == null) { throw new ArgumentNullException("array"); }
            const ushort vtUnknown = 13;
            IntPtr psa = PropVariantNativeMethods.SafeArrayCreateVector(vtUnknown, 0, (uint)array.Length);

            IntPtr pvData = PropVariantNativeMethods.SafeArrayAccessData(psa);
            try // to remember to release lock on data
            {
                for (int i = 0; i < array.Length; ++i)
                {
                    object obj = array.GetValue(i);
                    IntPtr punk = (obj != null) ? Marshal.GetIUnknownForObject(obj) : IntPtr.Zero;
                    Marshal.WriteIntPtr(pvData, i * IntPtr.Size, punk);
                }
            }
            finally
            {
                PropVariantNativeMethods.SafeArrayUnaccessData(psa);
            }

            _valueType = (ushort)VarEnum.VT_ARRAY | (ushort)VarEnum.VT_UNKNOWN;
            _ptr = psa;
        }

        #endregion

        #region public Properties

        /// <summary>
        /// Gets or sets the variant type.
        /// </summary>
        public VarEnum VarType
        {
            get { return (VarEnum)_valueType; }
            set { _valueType = (ushort)value; }
        }

        /// <summary>
        /// Checks if this has an empty or null value
        /// </summary>
        /// <returns></returns>
        public bool IsNullOrEmpty
        {
            get
            {
                return (_valueType == (ushort)VarEnum.VT_EMPTY || _valueType == (ushort)VarEnum.VT_NULL);
            }
        }

        /// <summary>
        /// Gets the variant value.
        /// </summary>
        public object Value
        {
            get
            {
                switch ((VarEnum)_valueType)
                {
                    case VarEnum.VT_I1:
                        return _sbyte;
                    case VarEnum.VT_UI1:
                        return _byte;
                    case VarEnum.VT_I2:
                        return _short;
                    case VarEnum.VT_UI2:
                        return _ushort;
                    case VarEnum.VT_I4:
                    case VarEnum.VT_INT:
                        return _int32;
                    case VarEnum.VT_UI4:
                    case VarEnum.VT_UINT:
                        return _uint32;
                    case VarEnum.VT_I8:
                        return _long;
                    case VarEnum.VT_UI8:
                        return _ulong;
                    case VarEnum.VT_R4:
                        return _float;
                    case VarEnum.VT_R8:
                        return _double;
                    case VarEnum.VT_BOOL:
                        return _int32 == -1;
                    case VarEnum.VT_ERROR:
                        return _long;
                    case VarEnum.VT_CY:
                        return _decimal;
                    case VarEnum.VT_DATE:
                        return DateTime.FromOADate(_double);
                    case VarEnum.VT_FILETIME:
                        return DateTime.FromFileTime(_long);
                    case VarEnum.VT_BSTR:
                        return Marshal.PtrToStringBSTR(_ptr);
                    case VarEnum.VT_BLOB:
                        return GetBlobData();
                    case VarEnum.VT_LPSTR:
                        return Marshal.PtrToStringAnsi(_ptr);
                    case VarEnum.VT_LPWSTR:
                        return Marshal.PtrToStringUni(_ptr);
                    case VarEnum.VT_UNKNOWN:
                        return Marshal.GetObjectForIUnknown(_ptr);
                    case VarEnum.VT_DISPATCH:
                        return Marshal.GetObjectForIUnknown(_ptr);
                    case VarEnum.VT_DECIMAL:
                        return _decimal;
                    case VarEnum.VT_ARRAY | VarEnum.VT_UNKNOWN:
                        return CrackSingleDimSafeArray(_ptr);
                    case (VarEnum.VT_VECTOR | VarEnum.VT_LPWSTR):
                        return GetVector<string>();
                    case (VarEnum.VT_VECTOR | VarEnum.VT_I2):
                        return GetVector<Int16>();
                    case (VarEnum.VT_VECTOR | VarEnum.VT_UI2):
                        return GetVector<UInt16>();
                    case (VarEnum.VT_VECTOR | VarEnum.VT_I4):
                        return GetVector<Int32>();
                    case (VarEnum.VT_VECTOR | VarEnum.VT_UI4):
                        return GetVector<UInt32>();
                    case (VarEnum.VT_VECTOR | VarEnum.VT_I8):
                        return GetVector<Int64>();
                    case (VarEnum.VT_VECTOR | VarEnum.VT_UI8):
                        return GetVector<UInt64>();
                    case (VarEnum.VT_VECTOR|VarEnum.VT_R4):
                        return GetVector<float>();
                    case (VarEnum.VT_VECTOR | VarEnum.VT_R8):
                        return GetVector<Double>();
                    case (VarEnum.VT_VECTOR | VarEnum.VT_BOOL):
                        return GetVector<Boolean>();
                    case (VarEnum.VT_VECTOR | VarEnum.VT_FILETIME):
                        return GetVector<DateTime>();
                    case (VarEnum.VT_VECTOR | VarEnum.VT_DECIMAL):
                        return GetVector<Decimal>();
                    default:
                        // if the value cannot be marshaled
                        return null;
                }
            }
        }

        #endregion

        #region Private Methods

        private static long GetFileTimeAsLong(ref System.Runtime.InteropServices.ComTypes.FILETIME val)
        {
            return (((long)val.dwHighDateTime) << 32) + val.dwLowDateTime;
        }

        private static System.Runtime.InteropServices.ComTypes.FILETIME DateTimeToFileTime(DateTime value)
        {
            long hFT = value.ToFileTime();
            System.Runtime.InteropServices.ComTypes.FILETIME ft =
                new System.Runtime.InteropServices.ComTypes.FILETIME();
            ft.dwLowDateTime = (int)(hFT & 0xFFFFFFFF);
            ft.dwHighDateTime = (int)(hFT >> 32);
            return ft;
        }

        private object GetBlobData()
        {
            byte[] blobData = new byte[_int32];

            IntPtr pBlobData = _ptr2;
            Marshal.Copy(pBlobData, blobData, 0, _int32);

            return blobData;
        }

        private Array GetVector<T>()
        {
            int count = PropVariantNativeMethods.PropVariantGetElementCount(this);
            if (count <= 0) { return null; }

            lock (_padlock)
            {
                if (_vectorActions == null)
                {
                    _vectorActions = GenerateVectorActions();
                }
            }

            Action<PropVariant, Array, uint> action;
            if (!_vectorActions.TryGetValue(typeof(T), out action))
            {
                throw new InvalidCastException(LocalizedMessages.PropVariantUnsupportedType);
            }

            Array array = new T[count];
            for (uint i = 0; i < count; i++)
            {
                action(this, array, i);
            }

            return array;
        }

        private static Array CrackSingleDimSafeArray(IntPtr psa)
        {
            uint cDims = PropVariantNativeMethods.SafeArrayGetDim(psa);
            if (cDims != 1)
                throw new ArgumentException(LocalizedMessages.PropVariantMultiDimArray, "psa");

            int lBound = PropVariantNativeMethods.SafeArrayGetLBound(psa, 1U);
            int uBound = PropVariantNativeMethods.SafeArrayGetUBound(psa, 1U);

            int n = uBound - lBound + 1; // uBound is inclusive

            object[] array = new object[n];
            for (int i = lBound; i <= uBound; ++i)
            {
                array[i] = PropVariantNativeMethods.SafeArrayGetElement(psa, ref i);
            }

            return array;
        }

        #endregion

        #region IDisposable Members

        /// <summary>
        /// Disposes the object, calls the clear function.
        /// </summary>
        public void Dispose()
        {
            PropVariantNativeMethods.PropVariantClear(this);

            GC.SuppressFinalize(this);
        }

        /// <summary>
        /// Finalizer
        /// </summary>
        ~PropVariant()
        {
            Dispose();
        }

        #endregion

        /// <summary>
        /// Provides an simple string representation of the contained data and type.
        /// </summary>
        /// <returns></returns>
        public override string ToString()
        {
            return string.Format(System.Globalization.CultureInfo.InvariantCulture,
                "{0}: {1}", Value, VarType.ToString());
        }

    }
	
	[DllImport("Shell32.dll")]
	public static extern int SHGetPropertyStoreForWindow([In] IntPtr hWnd,
														 [In] Guid riid,
														 [Out, MarshalAs(UnmanagedType.Interface)] out IPropertyStore ppv);
	
	// Sample Code
	
	
	
	int SetTouchDisableProperty(IntPtr hWnd, bool fDisableTouch)
	{
	
		IPropertyStore pPropStore;
		int hr = SHGetPropertyStoreForWindow(hWnd, new Guid("886D8EEB-8CF2-4446-8D02-CDBA1DBDCF99"), out pPropStore);
		if(hr == 0)
		{
			PropVariant v = new PropVariant(fDisableTouch);
			hr = pPropStore.SetValue(PKEY_EdgeGesture_DisableTouchWhenFullscreen, v);
		}
		return hr;
	
	}

Christian Graus wrote:

The guy on SO is still making sarcastic comments and calling me a moron....