程序代码：

这个是Array.h文件中的内容

#ifndef  ARRAY_H_H
#define  ARRAY_H_H
enum Erro
{
    IndexOutOf,
    InviladArraySize,
    MemoryAllocationErro
};

template<class T>
class Array
{
public:
    Array(int size=20);
    Array(Array<T>& _array);
    ~Array();
    T& operator [](int i);
    operator T*();
    void ReSize(int sz);
    int GetLength();
private:
    void     PrintErro(Erro erro);
   
    int size;
    T* data;
};
#endif 
这个是Array.cpp文件中的内容

#include "Array.h"
#include <iostream.h>
#include "stdlib.h"
#define NULL 0
char* ErroInfo[]={"下标出界","数组大小不正确","申请内存失败"};
template <class T>
Array<T>::Array(int size1)
{
    if(size1<0)
    {
        PrintErro(InviladArraySize);
    }
    size=size1;
    data=new T[size1];
    if(NULL==data)
    {
        PrintErro(MemoryAllocationErro);
        exit(1);
    }
}
template <class T>
Array<T>::Array(Array<T>& A_rray) 
{
    size= A_rray.size;
    data=new T[size];
    if(NULL==data)
    {   
        PrintErro(MemoryAllocationErro);
        exit(1);
    }
    else
    {
        for(int i=0;i<size;i++)
        {
            data[size]=A_rray.data[size];
        }
    }

}

template <class T>
T& Array<T>:: operator [](int i)  
{
    if(i>size || i<0)
    {
        PrintErro(IndexOutOf);
        exit(1);
    }
    return data[i];
}
template <class T>
Array<T>::operator T*()           
{
    return data;
}
template <class T>
int Array<T>::GetLength()      
{
    cout<<"元素个数 : "<<size<<endl;
    return size;
}
template <class T>
void  Array<T>::ReSize(int sz)
{   
    if(sz<NULL)   
    {
        PrintErro(MemoryAllocationErro);
        exit(1);
    }
    else if(sz<size)
    {
        size=sz;
        T* newdata=new T[sz];
        if(NULL==newdata)
        {
            PrintErro(MemoryAllocationErro);       
            exit(1);
        }
        T* pb=data;
        T* pn=newdata;
        while(sz--)
        {
            *pb++=*pn++;
        }
        delete []data;
        data=newdata;
    }
    else if(sz>size)
    {
        size=sz;
        int count=size;
        T* newdata=new T[sz];
        if(NULL==newdata)
        {
            exit(1);
        }
        T* pb=data;
        T* pn=newdata;
        while(count--)
        {
            *pb++=*pn++;
        }
        delete []data;
        data=newdata;   
    }
}
template <class T>
void Array<T>::PrintErro(Erro erro) 
{
    cout<<ErroInfo[erro]<<endl;
}

template <class T>
Array<T>::~Array()   
{
    delete []data;
}
这个是主程序文件main.cpp文件中的内容

#include "Array.h"
#include <iostream.h>
void main()
{

    Array<int> hello(1);
    hello[0]=10;
    hello[1]=20;
    cout<<"hello [0] "<<hello[0]<<endl;
    cout<<"hello [1] "<<hello[1]<<endl;

}

这个是错误 


--------------------Configuration: 11 - Win32 Debug--------------------
Compiling...
main.cpp
Linking...
main.obj : error LNK2001: unresolved external symbol "public: __thiscall Array<int>::~Array<int>(void)" (??1?$Array@H@@QAE@XZ)
main.obj : error LNK2001: unresolved external symbol "public: int & __thiscall Array<int>::operator[](int)" (??A?$Array@H@@QAEAAHH@Z)
main.obj : error LNK2001: unresolved external symbol "public: __thiscall Array<int>::Array<int>(int)" (??0?$Array@H@@QAE@H@Z)
Debug/11.exe : fatal error LNK1120: 3 unresolved externals
Error executing link.exe.

11.exe - 4 error(s), 0 warning(s)