C++/CLI 托管C++之字符串封装【5】

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【1】字符串作为输入参数

C++导出函数：

//1.1 字符串作为输入参数
EXPORTDLL_CLASS int Str_Output( WCHAR *pInStr )
{
  if (NULL == pInStr)
  {
    return(-1);
  }

  wprintf(L"Str_Output %s\n", pInStr);

  return(0);
}

CLI类封装：

/// <summary>
    /// 1 字符串测试类
    /// </summary>
    public ref class StrCls
    {
    public:
        /// <summary>
        /// 1.1 字符串作为输入参数
        /// </summary>
        /// <param name="pInStr">字符串</param>  
        /// <returns>成功返回0</returns> 
        static Int32 StrOutput(String^ pInStr);       
        /// <summary>
        /// 1.2 字符串作为参数,需要进行修改返回
        /// </summary>
        /// <param name="pOutStr">字符串</param>  
        /// <returns>成功返回0</returns> 
        static Int32 StrChange(String^ %pOutStr);        
        /// <summary>
        /// 1.3 字符串数组作为参数
        /// </summary>
        /// <param name="ppStr">字符串数组</param>  
        /// <returns>成功返回0</returns> 
        static Int32 StrChangeArr(array<String^>^ %ppStr);
    };

CLI函数实现：

System::Int32 ExportCLI::StrCls::StrOutput( String^ pInStr )
{
    if (String::IsNullOrEmpty(pInStr))
    {
        return(-1);
    }

    WCHAR   *pStr = ManagedStr2UnmanagedUniStr(pInStr);
    HRESULT  hr   = Str_Output(pStr);

    //内存释放
    if (NULL != pStr)
    {
        delete []pStr;
        pStr = NULL;
    }

    return(hr);
}

C#测试：

//1. 字符串测试类
string pInStr = "1.1";
StrCls.StrOutput(pInStr);

【2】字符串作为参数，需要返回修改

//1.2 字符串作为参数,需要进行修改返回
EXPORTDLL_CLASS int Str_Change( WCHAR *pOutStr)
{
    if (NULL == pOutStr)
    {
        return(-1);
    }

    int len = wcslen(pOutStr);
    for (int ix=0; ix<len-1; ix++)
    {
        pOutStr[ix] = 'a' + (ix) % 26;
    }
    pOutStr[len-1] = '\0\0';

    wprintf(L"Str_Change %s\n", pOutStr);
    return(0);
}

CLI函数实现：

System::Int32 ExportCLI::StrCls::StrChange( String^ %pOutStr )
{
    if (String::IsNullOrEmpty(pOutStr))
    {
        return(-1);
    }

    WCHAR   *pStr = ManagedStr2UnmanagedUniStr(pOutStr);
    HRESULT  hr   = Str_Change(pStr);

    pOutStr = UnmanagedStr2ManagedUniStr(pStr);

    //内存释放
    if (NULL != pStr)
    {
        delete []pStr;
        pStr = NULL;
    }

    return(hr);
}

C#测试：

string pOutStr = "1.2";
StrCls.StrChange(ref pOutStr);

【3】字符串数组作为参数，需要返回修改

C++导出函数：

//1.3 字符串数组作为参数
EXPORTDLL_CLASS int Str_ChangeArr( WCHAR **ppStr, int len )
{
  if (NULL == ppStr)
  {
    return(-1);
  }

  for (int ix=0; ix<len; ix++)
  {
    if (NULL != ppStr[ix])
    {
      lstrcpyn(ppStr[ix], L"abc", wcslen(ppStr[ix]));
    }
  }

  wprintf(L"Str_ChangeArr \n");
  return(0);
}

CLI函数实现：

System::Int32 ExportCLI::StrCls::StrChangeArr( array<String^>^ %ppStr )
{
    if (ppStr == nullptr)
    {
        return(-1);
    }

    int     len  = ppStr->Length; //数据元素的个数
    WCHAR   **pp = new WCHAR *[len];

    for (int ix=0; ix<len; ix++)
    {
        pp[ix] = ManagedStr2UnmanagedUniStr(ppStr[ix]);
    }
    HRESULT  hr   = Str_ChangeArr(pp, len);
    for (int ix=0; ix<len; ix++)
    {
        ppStr[ix] = UnmanagedStr2ManagedUniStr(pp[ix]);
    }

    //内存释放
    for (int ix=0; ix<len; ix++)
    {
        delete [](pp[ix]);
        pp[ix] = NULL;
    }
    delete []pp;
    pp = NULL;

    return(hr);
}

C#测试：

string[] ppStr = new string[2] { "1.31.......", "1.32......." };
StrCls.StrChangeArr(ref ppStr);