编组C结构在它的结构数组 [英] Marshalling C Struct with array of structures in it

问题描述

我提到了这个论坛类似的问题，但没有得到我的问题的解决方案。

I referred the similar questions in this forum but didn't get the solution for my problem.

我一直在一段时间封送处理问题所困扰。我有一个包含另一个结构的阵列结构，该平台的的Win CE 。我使用Visual Studio 2008和.NET CF 3.5

I have been struggling with marshaling problem for a while. I have a structure that contains an array of another structure, The platform is Win CE. I am using Visual Studio 2008 and .NET CF 3.5.

中的代码：

C结构：

 struct dot11Rate
 {
    unsigned int rate;
    unsigned char mode; 
 };

 typedef struct my_supported_rates
 {
    unsigned short n_rates;
    struct dot11Rate srates[36];
    unsigned char  isSet;
    unsigned char no_of_HTStreams;
 }MY_SUPPORTED_DATA_RATES;

的

结构MY_SUPPORTED_DATA_RATES大小为 296字节在 C

这是我尝试将其转换成一个C＃结构：

C＃转换：

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    public struct dot11Rate
    {
        public uint rate;
        public byte mode; /* HT=1, non-HT=0*////
    };

    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    public struct my_supported_rates
    {       
        public ushort n_rates;
        [MarshalAs(UnmanagedType.ByValArray,SizeConst = 36)]
        public dot11Rate[] srates;
        public byte isSet;
        public byte no_of_HTStreams;
    };

下面我收到的大小为 304字节是 Marshal.SizeOf（my_supported_rates）;

Here I am getting the size as 304 bytes using Marshal.SizeOf(my_supported_rates);

我曾尝试下面的东西没有任何成功：

I have tried the following things without any success:

• 添加和删除的MarshalAs各种attrubute元素my_supported_rates结构，如 ArraySubType = UnmanagedType.Struct
$属性b $ b
• 我的IntPtr与所需的数据，我试图PTR转换为使用的代码 my_supported_rates =（my_supported_rates）
Marshal.PtrToStructure（PTR，my_supported_rates.GetType的结构（） ）; 。但是适当的转换没有happend。


• 在博客和计算器这并不能证明$​​ B $ B对我有用的一些其他建议

• Adding and removing various attrubute elements in MarshalAs attribute in my_supported_rates struct such as ArraySubType = UnmanagedType.Struct
• I have Intptr with required data and I tried to convert ptr to the struct using the code my_supported_rates = (my_supported_rates) Marshal.PtrToStructure(ptr,my_supported_rates.GetType());. But proper conversion is not happend.
• Some other suggestions on blogs and StackOverflow which didn't prove useful to me

推荐答案

您的翻译看对我好。运行在桌面上，而不是CE我发现，对于这些类型的

Your translations look good to me. Running on desktop rather than CE I find that, for these types

[StructLayout(LayoutKind.Sequential)]
public struct dot11Rate
{
    public uint rate;
    public byte mode;
};

[StructLayout(LayoutKind.Sequential)]
public struct my_supported_rates
{       
    public ushort n_rates;
    [MarshalAs(UnmanagedType.ByValArray,SizeConst = 36)]
    public dot11Rate[] srates;
    public byte isSet;
    public byte no_of_HTStreams;
};

这

Marshal.SizeOf(typeof(my_supported_rates)) == 296

所以它似乎在行政长官的PInvoke编组一些奇怪的。您可能需要通过这样做是为了迫使编组的手：

So it would seem to be something odd in the CE pinvoke marshaller. You might need to force the hand of the marshaller by doing this:

[StructLayout(LayoutKind.Explicit, Size=296)]
public struct my_supported_rates
{       
    [FieldOffset(0)]
    public ushort n_rates;
    [FieldOffset(4)]
    [MarshalAs(UnmanagedType.ByValArray,SizeConst = 36)]
    public dot11Rate[] srates;
    [FieldOffset(292)]
    public byte isSet;
    [FieldOffset(293)]
    public byte no_of_HTStreams;
};

也就是说，如果 LayoutKind.Explicit 和 FieldOffset 支持在CE。

如果他们不支持，那么你就需要手工元帅。您正在寻找 Marshal.AllocHGlobal 然后 Marshal.ReadByte ， Marshal.ReadInt16 等。

If they are not supported then you'll need to marshal by hand. You are looking for Marshal.AllocHGlobal and then Marshal.ReadByte, Marshal.ReadInt16 and so on.

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