/// <summary>
/// Allocates from unmanaged memory to represent a structure with a
/// variable length array at the end and marshal these structure
/// elements. It is the callers responsibility to marshal what preceeds
/// the trailing array into the unmanaged memory. ONLY structures with
/// attribute StructLayout of LayoutKind.Sequential are supported.
/// </summary>
/// <typeparam name="T">Type of the trailing array of structures</typeparam>
/// <param name="prefixBytes">Number of bytes preceeding the trailing array of structures</param>
/// <param name="values">Collection of structure objects</param>
/// <param name="count"></param>
/// <returns>SafeHGlobalHandle object to an native (unmanaged) structure
/// with a trail array of structures</returns>
public static SafeHGlobalHandle AllocHGlobal <T>(int prefixBytes, IEnumerable <T> values, int count) where T : struct
{
//Debug.Assert(typeof(T).StructLayoutAttribute.Value == LayoutKind.Sequential);
SafeHGlobalHandle result = AllocHGlobal(prefixBytes + Marshal.SizeOf(typeof(T)) * count);
IntPtr ptr = new IntPtr(result.pointer.ToInt32() + prefixBytes);
foreach (var value in values)
{
Marshal.StructureToPtr(value, ptr, false);
ptr.Increment <T>();
}
return(result);
}
private static SafeHGlobalHandle AllocHGlobal(int cb)
{
if (cb < 0)
{
throw new ArgumentOutOfRangeException("cb", RS.NegativeLength);
}
SafeHGlobalHandle result = new SafeHGlobalHandle();
// CER
RuntimeHelpers.PrepareConstrainedRegions();
try { }
finally
{
result.pointer = Marshal.AllocHGlobal(cb);
}
return(result);
}
