用windows的DLL接口编写copy程序,
请教如何编写程序实现。

很简单

include  windows.h                                    ;常用数据结构、类型定义
include  kernel32.inc                                 ;CopyFile的包含文件头

includelib kernel32.lib                               ;CopyFile的实现，由于不是静态库。实际上这里会被编译程序构造为'PE'导入表         
.data
    SrcFile  db 'c:\1.txt',0                          ;源文件路径  
    DestFile db 'd:\11.txt',0                         ;目标文件路径

.........
invoke CopyFile,offset SrcFile,offset DestFile,FALSE   ;调用函数，完成Copy
..........

MSDN具体说明：
BOOL WINAPI CopyFile(
  __in  LPCTSTR lpExistingFileName,
  __in  LPCTSTR lpNewFileName,
  __in  BOOL bFailIfExists
);
 
Parameters
lpExistingFileName [in]  
The name of an existing file.  
 
In the ANSI version of this function, the name is limited to MAX_PATH characters. To extend this limit to 32,767 wide characters, call the Unicode version of the function and prepend "\\?\" to the path. For more information, see Naming a File.
 
If lpExistingFileName does not exist, CopyFile fails, and GetLastError returns ERROR_FILE_NOT_FOUND.
 
lpNewFileName [in]  
The name of the new file.  
 
In the ANSI version of this function, the name is limited to MAX_PATH characters. To extend this limit to 32,767 wide characters, call the Unicode version of the function and prepend "\\?\" to the path. For more information, see Naming a File.
 
bFailIfExists [in]  
If this parameter is TRUE and the new file specified by lpNewFileName already exists, the function fails. If this parameter is FALSE and the new file already exists, the function overwrites the existing file and succeeds.
 
Return Value
If the function succeeds, the return value is nonzero.
 
If the function fails, the return value is zero. To get extended error information, call GetLastError.
 

谢谢兄弟，我看不明白，你能不能把完整的实现代码贴出来。

.386
.model flat,stdcall
option casemap:none

include  windows.inc                                    ;常用数据结构、类型定义
include  kernel32.inc                                 ;CopyFile的包含文件头
 
includelib kernel32.lib                              
.data
    SrcFile  db 'c:\1.txt',0                          ;源文件路径   
    DestFile db 'd:\11.txt',0                         ;目标文件路径
.code
_start:
    invoke CopyFile,offset SrcFile,offset DestFile,FALSE   ;调用函数，完成Copy
    cmp eax,0
    jz @F
    jmp over
@@:
    mov eax,1
over:
    invoke ExitProcess,eax
end _start

兄弟太感谢，我们学校开了这门课，一点也不懂，
你帮了我大忙了。