演示遍历二叉树的过程，所以首先建立二叉树，并用图形显示出树的形状。建立的过程是采用前序便利的方法来创建，设计两种生成树的方式：一种是系统随机生成，另一种是人工输入。考虑到屏幕界面的有限性，限定二叉树不超过5层，最多26个字符，输入字符小数点“.”代表NULL。初始树为某种颜色的结点，三种情况的遍历采用填充另外一种醒目的颜色，来表示当前遍历的结点，同时显示该结点的访问序号。同时在遍历的过程中在遍历图形的下方显示出遍历序列。-Demonstration of the process of binary tree traversal, so first of all establish a binary tree, and graph shows that the shape of the tree. Established process is used to facilitate pre-order method to create, design spanning two ways: one is the system of randomly generated, and the other is manual input. Taking into account the limited nature of the interface screen, limited to not more than 5 tree layer, a maximum of 26 characters, enter the decimal point character　.　On behalf of NULL. The initial tree for a certain color nodes, three cases of traversal using fill another eye-catching colors, to indicate the traversal of the current node, at the same time revealed that the serial number of nodes visited. At the same time, the process of traversal in the traversal graph traversal sequence shown below.