实现统计字母频率，实现哈夫曼树的建立，并现实0 1代码，MFC GDI编程，还实现了发送，译码功能，接受，顺便还实现了聊天功能-Achieve statistical letter frequencies, to achieve the establishment of Huffman trees, and reality 01 code, MFC GDI programming, but also realized the sending, decoding functions to acce