Marshal.StructureToPtr没有装箱

Question

有没有一种方法来编组结构（可能存储在TypedReference）非托管内存没有实际装箱呢？结构的类型在运行时是未知的，所以我不能使用StructureToPtr（.NET 4.5.1）的通用重载。我可以得到一个MethodInfo的StructureToPtr重载，但似乎没有办法调用它通过通用引用或TypedReference。

编辑：通用StructureToPtr仍然结构的结构，所以试图调用它是没有用的。

Answer 1

我终于找到了答案，SafeBuffer类。它包含我想要的 - 使用TypedReference和通用参数的编组方法的结构。所以，这是非常简单的，然后进行包装：

public static unsafe class InteropTools 
{ 
    private static readonly Type SafeBufferType = typeof(SafeBuffer); 
    public delegate void PtrToStructureNativeDelegate(byte* ptr, TypedReference structure, uint sizeofT); 
    public delegate void StructureToPtrNativeDelegate(TypedReference structure, byte* ptr, uint sizeofT); 
    const BindingFlags flags = BindingFlags.NonPublic | BindingFlags.Static; 
    private static readonly MethodInfo PtrToStructureNativeMethod = SafeBufferType.GetMethod("PtrToStructureNative", flags); 
    private static readonly MethodInfo StructureToPtrNativeMethod = SafeBufferType.GetMethod("StructureToPtrNative", flags); 
    public static readonly PtrToStructureNativeDelegate PtrToStructureNative = (PtrToStructureNativeDelegate)Delegate.CreateDelegate(typeof(PtrToStructureNativeDelegate), PtrToStructureNativeMethod); 
    public static readonly StructureToPtrNativeDelegate StructureToPtrNative = (StructureToPtrNativeDelegate)Delegate.CreateDelegate(typeof(StructureToPtrNativeDelegate), StructureToPtrNativeMethod); 

    private static readonly Func<Type,bool,int> SizeOfHelper_f = (Func<Type,bool,int>)Delegate.CreateDelegate(typeof(Func<Type,bool,int>), typeof(Marshal).GetMethod("SizeOfHelper", flags)); 

    public static void StructureToPtrDirect(TypedReference structure, IntPtr ptr, int size) 
    { 
     StructureToPtrNative(structure, (byte*)ptr, unchecked((uint)size)); 
    } 

    public static void StructureToPtrDirect(TypedReference structure, IntPtr ptr) 
    { 
     StructureToPtrDirect(structure, ptr, SizeOf(__reftype(structure))); 
    } 

    public static void PtrToStructureDirect(IntPtr ptr, TypedReference structure, int size) 
    { 
     PtrToStructureNative((byte*)ptr, structure, unchecked((uint)size)); 
    } 

    public static void PtrToStructureDirect(IntPtr ptr, TypedReference structure) 
    { 
     PtrToStructureDirect(ptr, structure, SizeOf(__reftype(structure))); 
    } 

    public static void StructureToPtr<T>(ref T structure, IntPtr ptr) 
    { 
     StructureToPtrDirect(__makeref(structure), ptr); 
    } 

    public static void PtrToStructure<T>(IntPtr ptr, out T structure) 
    { 
     structure = default(T); 
     PtrToStructureDirect(ptr, __makeref(structure)); 
    } 

    public static T PtrToStructure<T>(IntPtr ptr) 
    { 
     T obj; 
     PtrToStructure(ptr, out obj); 
     return obj; 
    } 

    public static int SizeOf<T>(T structure) 
    { 
     return SizeOf<T>(); 
    } 

    public static int SizeOf<T>() 
    { 
     return SizeOf(typeof(T)); 
    } 

    public static int SizeOf(Type t) 
    { 
     return SizeOfHelper_f(t, true); 
    } 
} 

使用

Guid g = Guid.NewGuid(); 
int size = InteropTools.SizeOf(g); 
IntPtr mem = Marshal.AllocHGlobal(size); 
InteropTools.StructureToPtr(ref g, mem); 

Guid g2 = InteropTools.PtrToStructure<Guid>(mem); 

现在，它实际上有超过在Marshal类非通用对象回吐的方法有什么优势？看起来StructureToPtr需要的时间减少了大约80％，并且PtrToStructure可以减少将近95％的时间。此外，这些方法可以正确处理可空类型。