C# 封送windows CE结构中的字符数组

C# 封送windows CE结构中的字符数组,c#,compact-framework,pinvoke,C#,Compact Framework,Pinvoke,如何封送以下结构定义中的字符数组?在.Net CompactFramework中(适用于Windows CE) //事务请求结构 typedef struct _VXN_REQUEST { char DID [33]; char MID [33]; char TID [33]; char ClientRef [33]; char Payload [8192]; ULO

如何封送以下结构定义中的字符数组?在.Net CompactFramework中(适用于Windows CE)

//事务请求结构

typedef struct _VXN_REQUEST
{

    char        DID [33]; 
    char        MID [33]; 
    char        TID [33];  
    char        ClientRef [33]; 
    char        Payload [8192];
    ULONG       PayloadLength;
} VXN_REQUEST, *LPVXN_REQUEST;
我试着这样整理它,但似乎不起作用

        [StructLayout(LayoutKind.Sequential,CharSet=CharSet.Auto)]
        public struct VXN_REQUEST
        {
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 33)]
            public string DID;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 33)]
            public string MID;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 33)]
            public string TID;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 33)]
            public string ClientRef;
            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 33)]
            public string Payload;
            public uint PayloadLength;

        }
也像这样尝试过,但都不起作用,本机代码将其作为单个字符

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public struct VXN_REQUEST
{
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 33)]

    public char[] DID;
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 33)]

    public char[] MID;
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 33)]

    public char[] TID;
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 33)]

    public char[] ClientRef;
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 33)]

    public char[] Payload;
    public uint PayloadLength;
}

NET字符需要两个字节,它存储以utf-16编码的Unicode代码点。在声明中使用byte而不是char。如果您确实需要将这些字段设置为字符串,请使用Encoding.ASCII.GetBytes()填充字节[]。

将您的p/Invoke声明更改为接受字节[]而不是结构,然后按如下方式定义它:

public class VXN_REQUEST 
{
    private byte[] m_data;

    public const int Size = 8328;

    public VXN_REQUEST()
    {
        m_data = new byte[Size];
    }

    public static implicit operator byte[](VXN_REQUEST req)
    {
        return req.m_data;
    }

    public string DID
    {
        get { return Encoding.ASCII.GetString(m_data, 0, 33).Trim('\0'); }
        set 
        { 
            // TODO: verify that 'value' isn't too long
            // first clear the contents
            var empty = new byte[33];
            Buffer.BlockCopy(empty, 0, m_data, 0, empty.Length);
            // copy data
            Encoding.ASCII.GetBytes(value).CopyTo(m_data, 0); 
        }
    }

    public string MID
    {
        get { return Encoding.ASCII.GetString(m_data, 33, 33).Trim('\0'); }
    }

    public string TID
    {
        get { return Encoding.ASCII.GetString(m_data, 66, 33).Trim('\0'); }
    }

    public string ClientRef
    {
        get { return Encoding.ASCII.GetString(m_data, 99, 33).Trim('\0'); }
    }

    public string Payload
    {
        get { return Encoding.ASCII.GetString(m_data, 132, PayloadLength).Trim('\0'); }
    }

    public int PayloadLength
    {
        get { return BitConverter.ToInt32(m_data, 8324); }
    }
}

作为记录,33个字符的长度对我来说真的很奇怪。

感谢Ctacke,我认为这可能会起作用,但为什么属性是只读的,我需要将值传递给本机。我编辑了代码,并为DID成员添加了一个setter。只需将其复制到其他属性中,调整有效负载的偏移量和长度。感谢Ctacke,我很欣赏CTackle,这个类是否会直接封送到与结构相同的本机结构,如[MarshalAs(UnmanagedType.struct)]ref VXN_REQUEST lpVxnRequest,有些人认为它似乎无法将值传递给本机代码。did、mid等字符串是否能够在.netcompact框架中作为char[]封送到nativecode