编组 C# 结构

Question

我正在尝试序列化以下 C# 结构：

[Serializable]
[StructLayout(LayoutKind.Sequential, Size = 70, CharSet = CharSet.Ansi)]
public struct USSDContinueModel
{
    [MarshalAs(UnmanagedType.U4)]
    public uint Command_Length;

    [MarshalAs(UnmanagedType.U4)]
    public uint Command_ID;

    [MarshalAs(UnmanagedType.U4)]
    public uint Command_Status;

    [MarshalAs(UnmanagedType.U4)]
    public uint Sender_ID;

    [MarshalAs(UnmanagedType.U4)]
    public uint Receiver_ID;

    [MarshalAs(UnmanagedType.U1)]
    public uint Ussd_Version;

    [MarshalAs(UnmanagedType.U1)]
    public uint Ussd_Op_Type;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 21)]
    public string MsIsdn;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 21)]
    public string Service_Code;

    [MarshalAs(UnmanagedType.U1)]
    public uint Code_Scheme;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 182)]
    public string Ussd_Content;

    // Calling this method will return a byte array with the contents
    // of the struct ready to be sent via the tcp socket.
    public byte[] Serialize()
    {
        // allocate a byte array for the struct data
        var buffer = new byte[Marshal.SizeOf(typeof(USSDContinueModel))];

        // Allocate a GCHandle and get the array pointer
        var gch = GCHandle.Alloc(buffer, GCHandleType.Pinned);
        var pBuffer = gch.AddrOfPinnedObject();

        // copy data from struct to array and unpin the gc pointer
        Marshal.StructureToPtr(this, pBuffer, false);
        gch.Free();

        return buffer;
    }

    // this method will deserialize a byte array into the struct.
    public void Deserialize(ref byte[] data)
    {
        var gch = GCHandle.Alloc(data, GCHandleType.Pinned);
        this = (USSDContinueModel)Marshal.PtrToStructure(gch.AddrOfPinnedObject(), typeof(USSDContinueModel));
        gch.Free();
    }
}

当我尝试序列化结构的一个实例时说：

        public USSDContinueModel continueModel;
        continueModel.Command_Length = 174;
        continueModel.Command_ID = 0x00000070;
        continueModel.Command_Status = 0;
        continueModel.Sender_ID = 0x01000005;
        continueModel.Receiver_ID = 0x2900AB12;
        continueModel.Ussd_Version = 0x20;
        continueModel.Ussd_Op_Type = 0x01;
        continueModel.MsIsdn = "08098765476";
        continueModel.Service_Code = "*308";
        continueModel.Code_Scheme = 0x44;
        continueModel.Ussd_Content = "1. Continue if you are 18+ 2. Exit i";

我一直收到错误 "Type: USSDcontinueModel cannot be marshalled as an unmanaged structure; no meaningful size or offset can be computed"。

我注意到当我将 Ussd_Version、Ussd_Op_Type 和 Code_Scheme 设置为 [MarshalAs(UnmanagedType.U1)] 时会发生这种情况，但它与 [MarshalAs(UnmanagedType.U4) )].

[MarshalAs(UnmanagedType.U1)] 是不可编组的吗？我该怎么办？

Answer 1

所以在采用@theB 将 U1 数据类型声明为字节的建议之后。问题已解决。更新后的结构定义如下：

[Serializable]
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack=1)]
public struct USSDContinueModel
{
    [MarshalAs(UnmanagedType.U4)]
    public uint Command_Length;

    [MarshalAs(UnmanagedType.U4)]
    public uint Command_ID;

    [MarshalAs(UnmanagedType.U4)]
    public uint Command_Status;

    [MarshalAs(UnmanagedType.U4)]
    public uint Sender_ID;

    [MarshalAs(UnmanagedType.U4)]
    public uint Receiver_ID;

    [MarshalAs(UnmanagedType.U1)]
    public byte Ussd_Version;

    [MarshalAs(UnmanagedType.U1)]
    public byte Ussd_Op_Type;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 21)]
    public string MsIsdn;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 21)]
    public string Service_Code;

    [MarshalAs(UnmanagedType.U1)]
    public byte Code_Scheme;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 182)]
    public string Ussd_Content;

    // Calling this method will return a byte array with the contents
    // of the struct ready to be sent via the tcp socket.
    public byte[] Serialize()
    {
        // allocate a byte array for the struct data
        var buffer = new byte[Marshal.SizeOf(typeof(USSDContinueModel))];

        // Allocate a GCHandle and get the array pointer
        var gch = GCHandle.Alloc(buffer, GCHandleType.Pinned);
        var pBuffer = gch.AddrOfPinnedObject();

        // copy data from struct to array and unpin the gc pointer
        Marshal.StructureToPtr(this, pBuffer, false);
        gch.Free();

        return buffer;
    }

    // this method will deserialize a byte array into the struct.
    public void Deserialize(ref byte[] data)
    {
        var gch = GCHandle.Alloc(data, GCHandleType.Pinned);
        this = (USSDContinueModel)Marshal.PtrToStructure(gch.AddrOfPinnedObject(), typeof(USSDContinueModel));
        gch.Free();
    }
}

Answer 2

问题在于定义：

[MarshalAs(UnmanagedType.U1)]
public uint Ussd_Op_Type;

成员的大小不明确。如果 interop marshal 使用成员的大小，它将计算 4 个字节，而如果它使用 MarshalAs 属性，它将计算 1 个字节。更改成员以使用正确的尺寸类型，

[MarshalAs(UnmanagedType.U1)]
public byte Ussd_Op_Type;

应该可以解决这个问题。

编组 C# 结构

Marshalling a C# structure

c#

structure

marshalling