将值分配给从非托管cpp调用的c#中的地址用户定义结构

Question

考虑以下结构

 /*Structure defined in unmanaged dll written in cpp*/
 struct NSCASR_RCG_RES_ST
 {
 unsigned int ulSizeBytes;
 unsigned int ulWarnings;
 unsigned short usNumPhrases;
 wchar_t* pstrWaveformURI;
 unsigned int ulWaveformSizeBytes;
 unsigned int ulWaveformDuration;
 };

 /*Structure defined in c#*/
 struct NSCASR_RCG_RES_ST
 {

 unsigned int ulSizeBytes;
 unsigned int ulWarnings;
 unsigned short usNumPhrases;
 String pstrWaveformURI;
 unsigned int ulWaveformSizeBytes;
 unsigned int ulWaveformDuration;
 };

在我的 unmagaed DLL(cpp) 中，我通过传递结构地址来调用函数，如下所示：

 NSCASR_RCG_RES_ST result_recognize;
 ASR_Recognize_ResultsGet(&result_recognize);

在我的托管 DLL 中，定义类似于

 void ASR_Recognize_ResultsGet(NSCASR_RCG_RES_ST *recognize)
 {
 /*MRCP_MD_TO_ASR is namespace and Constants is class name
   which consists of structure NSCASR_RCG_RES_ST */

    MRCP_MD_TO_ASR::Constants::NSCASR_RCG_RES_ST *pRecognitionResults;
    pRecognitionResults = (MRCP_MD_TO_ASR::Constants::NSCASR_RCG_RES_ST *)recognize;
    MRCP_MD_TO_ASR::ASR_API::ASR_Recognize_ResultsGet(*pRecognitionResults);
 }

在 c# 代码中，我分配了以下成员

 public static int ASR_Recognize_ResultsGet(ref Constants.NSCASR_RCG_RES_ST pRecognitionResults)
 {
     pRecognitionResults = speech_results;
     pRecognitionResults.ulSizeBytes = 200;
     return 0;
 }

但是当我在语句执行后看到result_recognize的内容时值 200 被分配给 usNumPhrases 变量而不是 ulSizeBytes

Answer 1

我通过显式添加 structlayout 并使用 charset 获得了解决方案，因为 c# 使用 unicode 16，如果我们使用 IntPtr 概念，我们必须将其设置为 unicode 8

 [StructLayout(LayoutKind.Explicit, CharSet = CharSet.Ansi)]
    public struct NSCASR_RCG_PHRASE_ST
    {
        [FieldOffset(0)]
        public ushort usConfidence;
        [FieldOffset(2)]
        public ushort usNumItems;
        [FieldOffset(4)]
        public short sGrammarIndex;
        [FieldOffset(6)]
        public short sGrammarType;
    }


    [StructLayout(LayoutKind.Explicit, CharSet = CharSet.Ansi)]
    public unsafe struct NSCASR_RCG_RES_ST
    {

        [FieldOffset(0)]
        public uint ulSizeBytes;
        [FieldOffset(4)]
        public uint ulWarnings;
        [FieldOffset(8)]
        public ushort usNumPhrases;
        [FieldOffset(12)]
        public IntPtr pstrWaveformURI;
        [FieldOffset(16)]
        public uint ulWaveformSizeBytes;
        [FieldOffset(20)]
        public uint ulWaveformDuration;
    }

将值分配给从非托管cpp调用的c#中的地址用户定义结构

Assigning values to the address user defined structure in c# called from unmanaged cpp

c#

managed

unmanagedexports

user-defined-data-types