c# - Marshal Union(C ) 与结构包含 C# 中的数组

Question

我尝试在 C# 中编码非托管 C++ DLL，但编码器在创建我的联合时失败。

为什么这段代码会失败？

    [StructLayout(LayoutKind.Sequential)]
    public struct StructWithArray
    {
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
        public int[] MySimpleArray;
        //More Stuff
    }

    [StructLayout(LayoutKind.Explicit)]
    public struct Union
    {
        [FieldOffset(0)]
        public int Int; //Or anything else
        [FieldOffset(0), MarshalAs(UnmanagedType.Struct)]
        public StructWithArray MyStructWithArray;
        //More Structs
    }

然后构建联盟:

Union MyUnion = new Union();

如果我运行带有以下消息的代码，它会失败:(已翻译)

{"The Type "Union" of the Assembly [...] could not be loaded because it contained an Objectfield at Offset 0, which is not aligned correctly or got overlapped by a field which isnt a ObjectField":"Union"}

有什么建议吗？

Ps:原始代码已大大简化以仅显示问题。 Struct多了很多，Union也被另一个Struct包含了。

Answer 1

将 MySimpleArray 声明为固定的不安全数组:

[StructLayout(LayoutKind.Sequential)]
public unsafe struct StructWithArray
{
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
    public fixed int MySimpleArray[2];
    //More Stuff
}

[StructLayout(LayoutKind.Explicit)]
public struct Union
{
    [FieldOffset(0)]
    public int Int; //Or anything else
    [FieldOffset(0), MarshalAs(UnmanagedType.Struct)]
    public StructWithArray MyStructWithArray;
    //More Structs
}