public static bool TryGetMetadataByName(this IWICMetadataQueryReader meta, string name, out PropVariant value)
{
value = null;
int hr = ProxyFunctions.GetMetadataByName(meta, name, IntPtr.Zero);
if (hr >= 0)
{
value = new PropVariant();
var pvMarshal = new PropVariant.Marshaler();
var pvNative = pvMarshal.MarshalManagedToNative(value);
hr = ProxyFunctions.GetMetadataByName(meta, name, pvNative);
pvMarshal.MarshalNativeToManaged(pvNative);
pvMarshal.CleanUpNativeData(pvNative);
}
return(hr >= 0);
}
public IntPtr MarshalManagedToNative(object o)
{
if (o == null)
{
return(IntPtr.Zero);
}
var marshalType = PropVariantMarshalType.Automatic;
if (o is PropVariant)
{
pv = (PropVariant)o;
o = pv.Value;
marshalType = pv.MarshalType;
}
var pNativeData = allocatePropVariant();
if (o == null)
{
return(pNativeData);
}
var type = o.GetType();
if (!(o is Array))
{
if (marshalType == PropVariantMarshalType.Ascii)
{
var upv = new UnmanagedPropVariant();
upv.vt = (ushort)VarEnum.VT_LPSTR;
upv.pointerValue = Marshal.StringToCoTaskMemAnsi((string)o);
Marshal.StructureToPtr(upv, pNativeData, false);
}
else if (o is string)
{
var upv = new UnmanagedPropVariant();
upv.vt = (ushort)VarEnum.VT_LPWSTR;
upv.pointerValue = Marshal.StringToCoTaskMemUni((string)o);
Marshal.StructureToPtr(upv, pNativeData, false);
}
else if (o is DateTime)
{
var upv = new UnmanagedPropVariant();
upv.vt = (ushort)VarEnum.VT_FILETIME;
upv.int64Value = ((DateTime)o).ToFileTimeUtc();
Marshal.StructureToPtr(upv, pNativeData, false);
}
else
{
Marshal.GetNativeVariantForObject(o, pNativeData);
}
}
else if ((type.Equals(typeof(byte []))) || (type.Equals(typeof(sbyte []))) ||
(type.Equals(typeof(short[]))) || (type.Equals(typeof(ushort[]))) ||
(type.Equals(typeof(int []))) || (type.Equals(typeof(uint []))) ||
(type.Equals(typeof(long []))) || (type.Equals(typeof(ulong []))) ||
(type.Equals(typeof(float[]))) || (type.Equals(typeof(double[]))))
{
var a = (Array)o;
int count = a.Length;
int elementSize = Marshal.SizeOf(type.GetElementType());
var pNativeBuffer = Marshal.AllocCoTaskMem(elementSize * count);
var gch = GCHandle.Alloc(a, GCHandleType.Pinned);
for (int i = 0; i < count; i++)
{
var pNativeValue = Marshal.UnsafeAddrOfPinnedArrayElement(a, i);
for (int j = 0; j < elementSize; j++)
{
byte value = Marshal.ReadByte(pNativeValue, j);
Marshal.WriteByte(pNativeBuffer, elementSize * i + j, value);
}
}
gch.Free();
var upv = new UnmanagedPropVariant();
upv.vectorValue.count = (uint)count;
upv.vectorValue.ptr = pNativeBuffer;
upv.vt = (ushort)(pv ?? new PropVariant(o)).UnmanagedType;
Marshal.StructureToPtr(upv, pNativeData, false);
}
else if (type.Equals(typeof(string[])))
{
int count = ((Array)o).Length;
var pNativeBuffer = Marshal.AllocCoTaskMem(IntPtr.Size * count);
for (int i = 0; i < count; i++)
{
var strPtr = Marshal.StringToCoTaskMemUni(((string[])o)[i]);
Marshal.WriteIntPtr(pNativeBuffer, IntPtr.Size * i, strPtr);
}
var upv = new UnmanagedPropVariant();
upv.vectorValue.count = (uint)count;
upv.vectorValue.ptr = pNativeBuffer;
upv.vt = (ushort)(pv ?? new PropVariant(o)).UnmanagedType;
Marshal.StructureToPtr(upv, pNativeData, false);
}
else
{
throw new NotImplementedException();
}
return(pNativeData);
}
public static bool TrySetMetadataByName(this IWICMetadataQueryWriter meta, string name, PropVariant value)
{
var pvMarshal = new PropVariant.Marshaler();
var pvNative = pvMarshal.MarshalManagedToNative(value);
int hr = ProxyFunctions.SetMetadataByName(meta, name, pvNative);
pvMarshal.CleanUpNativeData(pvNative);
return(hr >= 0);
}
