我在调用具有特定签名的DLL库时遇到问题。这是在xamarin平台上并在iOS上运行。我想获得一个DNS服务器列表。我可以毫无问题地调用其他函数，但我真正需要的函数不起作用。我确信这是因为我的结构不正确。我认为问题是“联盟”类型。我只是不知道我的结构应该是什么样的安抚该参数。以下是相关的c ++类型：
1：DLL单一
-i2：c ++结构
`int res_getservers __P((res_state, union res_sockaddr_union * , int));`
任何有关生成正确的c＃结构的帮助将不胜感激！谢谢。
答案 0 :(得分：2)
免责声明：我的机器上没有安装C ++，但我相信这会有用，或者至少可以帮助你朝着正确的方向发展。
基于：https://msdn.microsoft.com/en-us/library/windows/desktop/ms738571(v=vs.85).aspx
并且：https://docs.microsoft.com/en-us/cpp/mfc/reference/sockaddr-in-structure
许多其他Google搜索相关类型。
using System;
using System.Runtime.InteropServices;
namespace SockStructTest
{
class Program
{
[StructLayout(LayoutKind.Explicit, Size = 8)]
public struct struct_sin_zero
{
[FieldOffset(0)]
public byte s_b1;
[FieldOffset(1)]
public byte s_b2;
[FieldOffset(2)]
public byte s_b3;
[FieldOffset(3)]
public byte s_b4;
[FieldOffset(4)]
public byte s_b5;
[FieldOffset(5)]
public byte s_b6;
[FieldOffset(6)]
public byte s_b7;
[FieldOffset(7)]
public byte s_b8;
[FieldOffset(0)]
public UInt64 s_ui64;
};
[StructLayout(LayoutKind.Explicit, Size = 4)]
public struct in_addr
{
[FieldOffset(0)]
public byte s_b1;
[FieldOffset(1)]
public byte s_b2;
[FieldOffset(2)]
public byte s_b3;
[FieldOffset(3)]
public byte s_b4;
[FieldOffset(0)]
public UInt16 s_w1;
[FieldOffset(2)]
public UInt16 s_w2;
[FieldOffset(0)]
public UInt32 S_addr;
};
[StructLayout(LayoutKind.Explicit, Size = 16)]
public struct sockaddr_in
{
[FieldOffset(0)]
public Int16 sin_family;
[FieldOffset(2)]
public UInt16 sin_port;
[FieldOffset(4)]
public in_addr sin_addr;
[FieldOffset(8)]
public struct_sin_zero sin_zero;
};
[StructLayout(LayoutKind.Explicit, Size = 16)]
public struct in6_addr_u
{
[FieldOffset(0)]
public byte Byte0;
[FieldOffset(1)]
public byte Byte1;
[FieldOffset(2)]
public byte Byte2;
[FieldOffset(3)]
public byte Byte3;
[FieldOffset(4)]
public byte Byte4;
[FieldOffset(5)]
public byte Byte5;
[FieldOffset(6)]
public byte Byte6;
[FieldOffset(7)]
public byte Byte7;
[FieldOffset(8)]
public byte Byte8;
[FieldOffset(9)]
public byte Byte9;
[FieldOffset(10)]
public byte ByteA;
[FieldOffset(11)]
public byte ByteB;
[FieldOffset(12)]
public byte ByteC;
[FieldOffset(13)]
public byte ByteD;
[FieldOffset(14)]
public byte ByteE;
[FieldOffset(15)]
public byte ByteF;
[FieldOffset(0)]
public UInt16 Word0;
[FieldOffset(2)]
public UInt16 Word1;
[FieldOffset(4)]
public UInt16 Word2;
[FieldOffset(6)]
public UInt16 Word3;
[FieldOffset(8)]
public UInt16 Word4;
[FieldOffset(10)]
public UInt16 Word5;
[FieldOffset(12)]
public UInt16 Word6;
[FieldOffset(14)]
public UInt16 Word7;
}
[StructLayout(LayoutKind.Explicit, Size = 16)]
public struct in6_addr
{
[FieldOffset(0)]
public in6_addr_u u;
}
[StructLayout(LayoutKind.Sequential, Pack = 4)]
public struct sockaddr_in6
{
public UInt64 sin6_len; // length of this struct(sa_family_t)
public UInt32 sin6_family; // AF_INET6 (sa_family_t)
public UInt16 sin6_port; // Transport layer port # (in_port_t)
public UInt32 sin6_flowinfo; // IP6 flow information
public in6_addr sin6_addr; // IP6 address
public UInt32 sin6_scope_id; // scope zone index
};
[StructLayout(LayoutKind.Explicit, Size = 16)]
public struct res_sockaddr_union
{
[FieldOffset(0)]
public sockaddr_in sin;
[FieldOffset(0)]
public sockaddr_in6 sin6;
[FieldOffset(0)]
public Int64 __align64;
[FieldOffset(0)]
public Int32 __align32;
// This is the char __space[128] bit.
// I've cheated and used 16 8 byte values.
[FieldOffset(0)]
public UInt64 __space0;
[FieldOffset(8)]
public UInt64 __space1;
[FieldOffset(16)]
public UInt64 __space2;
[FieldOffset(24)]
public UInt64 __space3;
[FieldOffset(32)]
public UInt64 __space4;
[FieldOffset(40)]
public UInt64 __space5;
[FieldOffset(48)]
public UInt64 __space6;
[FieldOffset(56)]
public UInt64 __space7;
[FieldOffset(64)]
public UInt64 __space8;
[FieldOffset(72)]
public UInt64 __space9;
[FieldOffset(80)]
public UInt64 __spaceA;
[FieldOffset(88)]
public UInt64 __spaceB;
[FieldOffset(96)]
public UInt64 __spaceC;
[FieldOffset(104)]
public UInt64 __spaceD;
[FieldOffset(112)]
public UInt64 __spaceE;
[FieldOffset(120)]
public UInt64 __spaceF;
}
static void Main(string[] args)
{
sockaddr_in ad;
ad.sin_zero.s_ui64 = 0;
ad.sin_family = 0; // or whatever
ad.sin_port = 1234;
// Address as b bit values
ad.sin_addr.s_b1 = 0;
ad.sin_addr.s_b2 = 1;
ad.sin_addr.s_b3 = 2;
ad.sin_addr.s_b4 = 3;
// Address as 16 bits
ad.sin_addr.s_w1 = 0;
ad.sin_addr.s_w2 = 0;
}
}
}
我能做的最好 - 如果没有解决你的问题，请不要感到压力接受答案，但请花点时间试着了解我给你的例子中发生了什么。
我没有机会测试它 - 但它确实构建了。
祝你好运！此致
亚当。