我们在VC本地代码的时候有时候需要动态数组，普通的数组肯定是不行的。托管的ArrayList又是托管的。那本地的怎么办？无非就是自己写一个。
#ifndef CARRAYLIST_H_H
#define CARRAYLIST_H_H
#include <string>
using namespace std;
#define IncreateSize (20)
/**
*@autho Rocky
*/ //20 increase when you need more space
// Define a class to implement a array list.
template <typename Object>
class ArrayList
{
public: // Construcotrs
// Initialize the instance of the ArrayList class.
ArrayList()
{
_list = NULL;
_supplySpace=_size = 0;
}
// Initialize the instance of the ArrayList class with a special count.
ArrayList(int count)
{
_supplySpace=_size = count;
_list = InitArray(_supplySpace);
}
public: // Destructors
// Uninitialize the instance of the ArrayList class.
~ArrayList()
{
if (_list != NULL)
delete[] _list;
_list = NULL;
_size = 0;
_supplySpace=0;
}
public: // Methods
// Gets the size of the array.
int Size()
{
return _size;
}
void ToTrimSize()
{
if(_size<=0)
{
delete []_list;
_list=NULL;
_supplySpace=_size=0;
}
else
{
if(_supplySpace==_size)//不需要精简
return;
Object *newPointer=InitArray(_size);
memcpy(newPointer,_list,_size*sizeof(Object));//拷贝过来实际的数量值
delete []_list;
///最后的精简数据，刚刚合适
_list=newPointer;
_supplySpace=_size;
}
}
// Sets the value at specail index.
bool SetItem(int index, Object value)
{
// index out of range
if (index < 0 || index >= _size)
return false;
// set value
_list[index] = value;
return true;
}
// Gets the value at special index.
Object GetItem(int index)
{
/* if ( index < 0 || index >= _size )
{
Object o;
return o;
}*/
return _list[index];
}
// add a item at the tail of array with a special value.
void Add(Object value)
{
if (_list != NULL)
{
if(_size<_supplySpace)
{
_list[_size]=value;
_size++;
}
else
{ //空间不够，需要增加
_supplySpace=_supplySpace+IncreateSize;//每次增加IncreateSize
Object *tmpList = InitArray(_supplySpace);
// copy the data from _list to temp array memory.
memcpy(tmpList, _list, _size*sizeof(Object));
// set special value at the end of array.
tmpList[_size] = value;
// clear old array memory.
delete[] _list;
// point _list to tmpList's memory.
_list = tmpList;
// modify the size of the current array.
_size += 1;
}
}
else // array has not been created.
{
_supplySpace=_supplySpace+IncreateSize;//每次增加IncreateSize
_list = InitArray(_supplySpace);
// set value.
_list[0] = value;
// set array size.
_size = 1;
}
}
// Remove the item from special index.
bool RemoveAt(int index)
{
return RemoveRange(index, 1);
}
// Insert a item at special index.
bool InsertAt(int index, Object value)
{
bool succeed = true;
// insert a empty item to array.
succeed = InsertRange(index, 1);
// if insert failed, return false.
if (!succeed)
return false;
// set value
_list[index] = value;
return true;
}
// Insert a continue space into array at special index.
bool InsertRange(int index, int count)
{
if (index < 0 || index > _size)
return false;
if (_list != NULL)
{
_supplySpace=_size + count;//当前的实际需求总量
Object *tmpList = InitArray(__supplySpace);
if (index == _size)
{//仅仅需要拷贝一次
// if index == _count, add the range to the tail of array
memcpy(tmpList, _list, _size*sizeof(Object));
}
else
{//需要多次拷贝
// if index >= 0 || index < _count, insert the range to array
memcpy(tmpList, _list, index*sizeof(Object));
memcpy(tmpList + index + count,
_list + index,
(_size - index) * sizeof(Object));
}
// clear the memory of the old array.
delete[] _list;
// point the _list to the new memory of current array.
_list = tmpList;
// modify the array count.
_size=_supplySpace;
}
else
{
_size =_supplySpace= count;
_list = InitArray(_supplySpace);
}
return true;
}
//
//删除从Index开始的count数量删除
//
bool RemoveRange(int index, int count)
{
if (_list == 0 || index < 0 || index >= _size)
return false;
if(index+count>=_size)
_supplySpace=index;
else
_supplySpace=_size - count;
Object *tmpList=InitArray(_supplySpace);//分配需要的大小的控件
memcpy(tmpList, _list, index*sizeof(Object));//把Index前面的所有全部保存起来
if(index+count<_size)
memcpy(tmpList+index,_list+index+count,(_size-index-count)*sizeof(Object));
delete []_list;
_list=tmpList;
_size=_supplySpace;
return true;
}
private:
// Instance Data
// define the pointer which point to memory of array.
Object *_list;
// save the size of array.
int _size; //实际大小
int _supplySpace; //实际申请的空间
private:
// Methods
// create a new array which type is Object and initialize each item with 0.
Object* InitArray(int count)
{
// craete new array
Object *newarray = new Object[count];
memset(newarray,0,sizeof(Object)*count);
return newarray;
}
};
#endif