开发一个简单的记事本

"""开发一个简单的记事本。
    包含：新建、保存、修改文本内容、退出
    包含：各种快捷建的处理
    version 1.0
"""

from tkinter import *
from tkinter.filedialog import *
from tkinter.colorchooser import *

class Application(Frame):

    def __init__(self, master=None):
        super().__init__(master)  # super()代表的是父类的定义，而不是父类的对象
        self.master = master
        self.textpad = None  # textpad代表Text文本框对象
        self.filename = None  # filename代表打开文本文件的名字
        self.contextMenu = None  # contextMenu代表上下文菜单对象
        self.pack()
        self.create_widget()

    def create_widget(self):
        """创建主菜单栏"""
        menubar = Menu(root)

        # 创建子菜单
        menu_file = Menu(menubar)
        menu_edit = Menu(menubar)
        menu_help = Menu(menubar)

        # 将子菜单加入到主菜单栏
        menubar.add_cascade(label="文件(F)", menu=menu_file)
        menubar.add_cascade(label="编辑(E)", menu=menu_edit)
        menubar.add_cascade(label="帮助(H)", menu=menu_help)

        # 添加菜单项
        menu_file.add_command(label="新建", accelerator="ctrl+n", command=self.newfile)
        menu_file.add_command(label="打开", accelerator="ctrl+o", command=self.openfile)
        menu_file.add_command(label="保存", accelerator="ctrl+s", command=self.savefile)
        menu_file.add_command(label="退出", accelerator="ctrl+q", command=self.exit)
        # 将主菜单栏加到根窗口
        root["menu"] = menubar

        # 添加快捷键事件梳理
        root.bind("<Control-n>", lambda event: self.newfile())
        root.bind("<Control-o>", lambda event: self.openfile())
        root.bind("<Control-q>", lambda event: self.exit())

        # 文本编辑区
        self.textpad = Text(root, width=50, height=30)
        self.textpad.pack()

        # 创建上下菜单
        self.contextMenu = Menu(root)
        self.contextMenu.add_command(label="背景颜色", command=self.openAskColor)

        # 为右键绑定事件
        root.bind("<Button-3>", self.createContextMenu)

    def newfile(self):
        self.textpad.delete('1.0', 'end')
        self.filename = asksaveasfilename(title="另存为", initialdir='未命名.txt', filetypes=[("文本文档", "*.txt")], defaultextension='.txt')
        print(self.filename)

        self.savefile()

    def openfile(self):
        self.textpad.delete('1.0', 'end')
        with askopenfile(title="打开文件") as f:
            self.textpad.insert(INSERT, f.read())
            self.filename = f.name
            print(f.name)

    def savefile(self):
        with open(self.filename, 'w') as f:
            c = self.textpad.get(1.0, END)
            f.write(c)

    def exit(self):
        root.quit()

    def openAskColor(self):
        s1 = askcolor(color="red", title="选择背景色")
        self.textpad.config(bg=s1[1])

    def createContextMenu(self, event):
        """菜单在鼠标右键单击坐标处显示"""
        self.contextMenu.post(event.x_root, event.y_root)

if __name__ == '__main__':
    root = Tk()
    root.geometry("450x300+200+300")
    root.title("明算软件的简易记事本")
    app = Application(master=root)
    root.mainloop()