C++:Catch块没有捕获？

Question

我有一个特定的Exception类,我想从类方法中抛出并从main()函数中调用它的调用代码.

但是,当我运行它时,我收到以下错误: Unhandled exception at 0x775915ee in OpenHashTable.exe: 0xC0000005: Access violation.好像它没有被处理.我不明白为什么会这样.这是涉及的代码:

main() {
    ......
        case 'i':   
        {
                cout << "Enter the positive integer you wish to insert: ";
                    //Input Validation.  
                if (!(cin >> number))
                {
                    cout << "Please enter a valid positive integer...\n\n";
                    cin.clear();
                    cin.ignore(numeric_limits<streamsize>::max(), '\n'); //Taken from http://stackoverflow.com/questions/2075898/good-input-validation-loop-using-cin-c
                    break;
                }
                try
                {
                    hashTable.add(abs(number)); //Add positive only integer
                }
                catch (FullTableException& fte)
                {
                    cout << "HashTable is full!" << endl;
                    break;
                }
                catch (DuplicateElementException& dee) //NOT BEING CAUGHT?
                {
                    cout << "HashTable already contains that element." << endl;     
                    break;
                }
                cout << abs(number) << " added!\n\n";
                break;
        }
     .......
}

这是在HashTable :: add()方法中抛出的异常

    //Adds an element into the appropriate index
bool OpenHashTable::add(int toAdd) throw(FullTableException, DuplicateElementException)
{
  int index = hash(toAdd);

  //Check for duplicate
  if (search(toAdd))
      throw DuplicateElementException();  //NOT ACTUALLY THROWING??

  if (arr[index] != 0) //If element is occupied   //GET AN ACCESS VIOLATION HERE
  {
      int j = 0;

      //Linear Probing...
      for ( unsigned int i = index + 1; j < 100; i = ((i+1) % 100) )
      {
          if (arr[i] != 0 && arr[i] != -1) //If element is occupied
          {
              j++;          //Keep count of how many tries, for full array
              continue;
          }
          else
          {
              arr[i] = toAdd;   //Add to array
              size++;           //Increment size
              break;
          }

      }
      if (j == 100) //We've checked all possible elements
          throw FullTableException();   //No spaces
  }
  else
  {
      arr[index] = toAdd;   //Add to array straight away
      size++;               //Increment size
  }
  return true;  //Successfully added

}

编辑:search()方法:

    bool OpenHashTable::search(int toSearch)
{
    int index = hash(toSearch);

if (arr[index] == toSearch)
    return true;    //Found at index
else
{
    int j = 0;
        //Linear search for value
    for ( unsigned int i = index + 1; j < 100; i = ((i+1) % 100) )
    {
        if (arr[i] == toSearch)
            return true;    //found
        else if (arr[i] == 0)
            return false;   //Not in HashTable
        else 
            continue;   //Probe next element
    }
    if (j == 100)
        return false;   //Not in HashTable
}
return true;
}

编辑:_ 尝试... _except()调用堆栈:

    ntdll.dll!775915ee()    
[Frames below may be incorrect and/or missing, no symbols loaded for ntdll.dll] 
ntdll.dll!775915ee()    
ntdll.dll!7761852f()    
ntdll.dll!776372ec()    
ntdll.dll!7760063e()    
ntdll.dll!775fabf9()    
ntdll.dll!77580143()    
KernelBase.dll!75c5b9bc()   
KernelBase.dll!75c5b9bc()   
KernelBase.dll!75c5b9bc()   
msvcr100d.dll!_CxxThrowException(void * pExceptionObject, const _s__ThrowInfo * pThrowInfo)  Line 157   C++
OpenHashTable.exe!OpenHashTable::add(int toAdd)  Line 100   //THIS IS "throw DuplicateElementException()"

OpenHashTable.exe!main()  Line 267    //THIS IS "hashTable.add(abs(number));"

编辑:DuplicateElementException:

//Just an empty class
class DuplicateElementException : public exception
{
private:
public:
    DuplicateElementException();   //Constructor
    ~DuplicateElementException();   //Destructor
};
//empty constructor and destructor definitions...

任何帮助深表感谢.

谢谢

Calum

Answer 1

抛出的异常是SEH异常"访问冲突",这意味着您从无效地址读取或写入.这可能是一个错误search或hash.并且你的程序没有到达你抛出的那一行DuplicateElementException.

此外,不推荐使用异常规范(函数原型之后的抛出),因此不要使用它们.