本地文件复制，实现功能相当于粘贴，复制操作。利用CFile类，先读出源文件内存，再新建一个文件并将内存中的内容写入该文件，达到复制目的-Local file copy, paste to achieve the functional equivalent, copy operation. Use CFile class, the first memory to read out the source file, and then create a new file and the contents of memory to write the file to copy the purpose of