Python GUI编程入门(31)-Treeview控件

Treeview是Tkinter8.5新引入的控件，可以用于实现较为复杂的GUI界面。本文使用一个FileBrowser实例来说明它的用法。

构建主窗口和退出菜单的代码和前一篇文章几乎相同：

root = Tk()
root.title('Tkinter Treeview and PanedWindow Demo V1.0')
root.grid_rowconfigure(0, weight=1)
root.grid_columnconfigure(0, weight=1)

screen_w = root.winfo_screenwidth()
screen_h = root.winfo_screenheight()
root.maxsize(width=screen_w, height=screen_h)
rw = int(screen_w / 2)
rh = int(screen_h / 2)
root.geometry('{}x{}+{:g}+{:g}'.format(rw, rh, rw / 2, rh / 2))

top_menu = Menu(root)
root.config(menu=top_menu)

file_menu = Menu(top_menu, tearoff=False)
top_menu.add_cascade(label='File', menu=file_menu)
file_menu.add_command(label="Exit", command=root.quit)

欢迎大家来到IT世界,在知识的湖畔探索吧!

构建一个水平方向的PanedWindow控件，grid布局时sticky属性设置为四面填充。

欢迎大家来到IT世界,在知识的湖畔探索吧!paned_window = PanedWindow(root, orient=HORIZONTAL)paned_window.grid(row=0, column=0, sticky='eswn')

构建管理左侧控件的Frame对象：

tree_area = Frame(paned_window)
tree_area.grid_rowconfigure(0, weight=1)
tree_area.grid_columnconfigure(0, weight=1)
paned_window.add(tree_area)

准备Treeview图标文件：

欢迎大家来到IT世界,在知识的湖畔探索吧!cur_path = os.path.abspath(os.path.dirname(__file__))
pc_image = PhotoImage(file=cur_path + '\\images\\pc.png')
drive_image = PhotoImage(file=cur_path + '\\images\\drive.png')
folder_image = PhotoImage(file=cur_path + '\\images\\folder.png')
file_image = PhotoImage(file=cur_path + '\\images\\file.png')

构建Treeview控件。将show属性指定为’tree’可以消除顶部的标题行。

tree_view = Treeview(tree_area, show='tree', selectmode='browse')
tree_view.grid(row=0, column=0, sticky='nsew')

添加水平和垂直滚动条：

scroll_ty = Scrollbar(tree_area, orient=VERTICAL, command=tree_view.yview)
scroll_ty.grid(row=0, column=1, sticky=N+S)
tree_view['yscrollcommand']=scroll_ty.set

scroll_tx = Scrollbar(tree_area, orient=HORIZONTAL, command=tree_view.xview)
scroll_tx.grid(row=1, column=0, sticky=E+W)
tree_view['xscrollcommand']=scroll_tx.set

增加根节点及驱动器节点：

pc_node= tree_view.insert('', 'end',
 text=os.environ.get('COMPUTERNAME'),
 image=pc_image,
 open=False)
for c in string.ascii_uppercase:
 disk = c + ':'
 if os.path.isdir(disk):
 drive_node = tree_view.insert(pc_node, 'end', text=disk, image=drive_image)

给定节点，获得节点路径的函数：

def node_path(node):
 path = ''
 parent = node
 while parent:
 node_text = tree_view.item(parent, 'text')
 if len(path) > 0:
 path = os.path.join(node_text, path)
 else:
 path = node_text
 parent = tree_view.parent(parent)
 return path

由于磁盘目录的结构一般都会非常复杂，因此本示例采用以下策略：

1. 展开节点时才会读入下级节点目录结构
2. 关闭节点时删除下级节点的目录结构

def open_node(event):
 focus = tree_view.focus()
 for node in tree_view.get_children(focus):
 insert_child_items(node)

tree_view.bind('<<TreeviewOpen>>', open_node)

def close_node(event):
 focus = tree_view.focus()
 for node in tree_view.get_children(focus):
 children = tree_view.get_children(node)
 for c in children:
 tree_view.delete(c)

insert_child_items的实现如下：

def insert_child_items(parent_node):
 path = node_path(parent_node)
 if os.path.isdir(path):
 try:
 dir_items = os.scandir(path)
 for item in dir_items:
 if item.is_dir() and ('.