二叉树插入（仅获取最后一项......）

I'm trying to load a file which has couple of infor, and I want to add them into a binary tree. For sure there is no problem with addToTree and printPreOrder functions, but i don't know why I can only print ( or maybe add ) the last item in the file. Whats the problem?I'm trying to load a file which has couple of i