c++ - 映射清除抛出异常

Question

我有一个 map 和过程来添加这样的数据:

interface CDBColumnInfo
      : public IDBColumnInfo
    {
    public:
        CDBColumnInfo();
        ~CDBColumnInfo();
   private:
    map<int,_bstr_t> m_rowIndexDataMap ;

   HRESULT AddDataToMap(){
    _bstr_t record;
    for (int rownum = 0; rownum < num_rows; ++rownum){
        const int num_cols = PQnfields(res);
        record = "";
        for (int colnum = 0; colnum < num_cols; ++colnum) {
            if (PQgetisnull(res, rownum, colnum) == 0) {
                _bstr_t data = PQgetvalue(res, rownum, colnum);
                record = record + data;
            }
            else {
                record = record + "<NULL>";
            }

            if (colnum + 1 < num_cols) {
                record = record + "#";
            }
        }
        m_rowIndexDataMap[rownum] = record;             
    }

  }

程序完成后，我通过以下方式清除析构函数中的映射:

CDBColumnInfo::~CDBColumnInfo() {
 m_rowIndexDataMap.clear();
}

析构函数完成时出现异常:

File: minkernel\crts\ucrt\src\appcrt\heap\debug_heap.cpp
Line: 904

Expression: _CrtIsValidHeapPointer(block)

我尝试循环映射并手动确定第一个元素中发生的异常:

for (auto it = m_rowIndexDataMap.cbegin(); it != m_rowIndexDataMap.cend() ;)
{       

    it = m_rowIndexDataMap.erase(it);    //  exception happened at first element

}
m_rowIndexDataMap.clear();

map 中的数据有什么问题？

Answer 1

您收到的错误:

File: minkernel\crts\ucrt\src\appcrt\heap\debug_heap.cpp Line: 904

Expression: _CrtIsValidHeapPointer(block)

不一定是由“实际”代码或调用堆栈引起的，但很可能是由代码中的其他地方引起的，因为它可能是由堆的例行检查引起的:

Heap-Check Frequency Macros

You can specify how often the C run-time library performs validation of the debug heap (_CrtCheckMemory) based on the number of calls to malloc, realloc, free, and _msize.

有关详细信息，请参阅 _CrtSetDbgFlag