请帮我编写基于python语言的根据学习生活桌面应用程序，具体要求：（1）使用类实现数据封装（2）使用tkinter实现界面UI设计（3）使用文件保存数据（4）能实现用户登录功能和实现数据的增加、修改、删除和查询

好的，我会为您解答这个问题。首先，您需要了解Python中的类和Tkinter库，以及如何使用文件保存数据。接下来，我们将一步步实现这个桌面应用程序。

1. 首先，创建一个名为“Student”的类，用于封装学生的信息，包括姓名、年龄、学号和成绩等。代码如下：

class Student:
    def __init__(self, name, age, student_id, score):
        self.name = name
        self.age = age
        self.student_id = student_id
        self.score = score

2. 然后，我们使用Tkinter库创建一个用户界面，包括登录界面和主界面。登录界面包括用户名和密码的输入框，以及登录按钮。主界面包括菜单栏、添加、修改、删除和查询按钮，以及一个用于显示学生信息的表格。代码如下：

import tkinter as tk
from tkinter import ttk

class Application(tk.Tk):
    def __init__(self):
        super().__init__()

        # 创建登录界面
        self.title("登录")
        self.geometry("200x100")

        self.username_label = tk.Label(self, text="用户名")
        self.username_label.pack()

        self.username_entry = tk.Entry(self)
        self.username_entry.pack()

        self.password_label = tk.Label(self, text="密码")
        self.password_label.pack()

        self.password_entry = tk.Entry(self, show="*")
        self.password_entry.pack()

        self.login_button = tk.Button(self, text="登录", command=self.login)
        self.login_button.pack()

        # 创建主界面
        self.main_menu = tk.Menu(self)
        self.config(menu=self.main_menu)

        self.file_menu = tk.Menu(self.main_menu, tearoff=False)
        self.main_menu.add_cascade(label="文件", menu=self.file_menu)

        self.add_button = tk.Button(self, text="添加", command=self.add_student)
        self.add_button.pack()

        self.modify_button = tk.Button(self, text="修改", command=self.modify_student)
        self.modify_button.pack()

        self.delete_button = tk.Button(self, text="删除", command=self.delete_student)
        self.delete_button.pack()

        self.query_button = tk.Button(self, text="查询", command=self.query_student)
        self.query_button.pack()

        self.student_table = ttk.Treeview(self, columns=("name", "age", "student_id", "score"), show="headings")
        self.student_table.pack()

        self.student_table.heading("name", text="姓名")
        self.student_table.heading("age", text="年龄")
        self.student_table.heading("student_id", text="学号")
        self.student_table.heading("score", text="成绩")

    def login(self):
        # 处理登录逻辑
        pass

    def add_student(self):
        # 处理添加学生逻辑
        pass

    def modify_student(self):
        # 处理修改学生逻辑
        pass

    def delete_student(self):
        # 处理删除学生逻辑
        pass

    def query_student(self):
        # 处理查询学生逻辑
        pass

3. 接下来，我们使用文件保存学生信息。学生信息将保存在名为“students.txt”的文件中。每行包含一个学生的信息，以逗号分隔。代码如下：

class Application(tk.Tk):
    def __init__(self):
        super().__init__()

        # ...

        # 加载学生信息
        self.load_students()

    def load_students(self):
        try:
            with open("students.txt", "r") as f:
                for line in f.readlines():
                    name, age, student_id, score = line.strip().split(",")
                    student = Student(name, age, student_id, score)
                    self.add_student_to_table(student)
        except FileNotFoundError:
            pass

    def save_students(self):
        with open("students.txt", "w") as f:
            for student in self.students:
                f.write(f"{student.name},{student.age},{student.student_id},{student.score}\n")

4. 最后，我们实现登录、添加、修改、删除和查询功能。登录功能验证用户名和密码是否正确，添加、修改、删除和查询功能则分别显示不同的对话框，让用户输入相应的信息。代码如下：

import tkinter.messagebox as messagebox

class Application(tk.Tk):
    def __init__(self):
        super().__init__()

        # ...

    def login(self):
        username = self.username_entry.get()
        password = self.password_entry.get()

        if username == "admin" and password == "123456":
            self.title("学生管理系统")
            self.geometry("600x400")
            self.username_label.destroy()
            self.username_entry.destroy()
            self.password_label.destroy()
            self.password_entry.destroy()
            self.login_button.destroy()
            self.add_button.pack(side="left")
            self.modify_button.pack(side="left")
            self.delete_button.pack(side="left")
            self.query_button.pack(side="left")
        else:
            messagebox.showerror("错误", "用户名或密码错误")

    def add_student(self):
        dialog = AddStudentDialog(self)
        self.wait_window(dialog)

    def modify_student(self):
        selected = self.student_table.focus()
        if not selected:
            messagebox.showwarning("警告", "请选择一个学生")
            return

        student = self.students[self.student_table.index(selected)]
        dialog = ModifyStudentDialog(self, student)
        self.wait_window(dialog)

    def delete_student(self):
        selected = self.student_table.focus()
        if not selected:
            messagebox.showwarning("警告", "请选择一个学生")
            return

        student = self.students[self.student_table.index(selected)]
        if messagebox.askyesno("确认", f"确定要删除学生 {student.name} 吗？"):
            self.remove_student(student)

    def query_student(self):
        dialog = QueryStudentDialog(self)
        self.wait_window(dialog)

    def add_student_to_table(self, student):
        self.student_table.insert("", "end", values=(student.name, student.age, student.student_id, student.score))
        self.students.append(student)
        self.save_students()

    def modify_student_in_table(self, index, student):
        self.student_table.item(self.student_table.get_children()[index], values=(student.name, student.age, student.student_id, student.score))
        self.students[index] = student
        self.save_students()

    def remove_student_from_table(self, index):
        self.student_table.delete(self.student_table.get_children()[index])
        del self.students[index]
        self.save_students()

class AddStudentDialog(tk.Toplevel):
    def __init__(self, parent):
        super().__init__(parent)

        self.title("添加学生")

        self.name_label = tk.Label(self, text="姓名")
        self.name_label.pack()

        self.name_entry = tk.Entry(self)
        self.name_entry.pack()

        self.age_label = tk.Label(self, text="年龄")
        self.age_label.pack()

        self.age_entry = tk.Entry(self)
        self.age_entry.pack()

        self.student_id_label = tk.Label(self, text="学号")
        self.student_id_label.pack()

        self.student_id_entry = tk.Entry(self)
        self.student_id_entry.pack()

        self.score_label = tk.Label(self, text="成绩")
        self.score_label.pack()

        self.score_entry = tk.Entry(self)
        self.score_entry.pack()

        self.add_button = tk.Button(self, text="添加", command=self.add_student)
        self.add_button.pack()

    def add_student(self):
        name = self.name_entry.get()
        age = self.age_entry.get()
        student_id = self.student_id_entry.get()
        score = self.score_entry.get()

        if not name or not age or not student_id or not score:
            messagebox.showwarning("警告", "请填写完整信息")
            return

        try:
            age = int(age)
            student_id = int(student_id)
            score = int(score)
        except ValueError:
            messagebox.showerror("错误", "年龄、学号和成绩必须是整数")
            return

        if not 0 <= age <= 150:
            messagebox.showerror("错误", "年龄必须在0至150之间")
            return

        if not 100000 <= student_id <= 999999:
            messagebox.showerror("错误", "学号必须是6位数字")
            return

        if not 0 <= score <= 100:
            messagebox.showerror("错误", "成绩必须在0至100之间")
            return

        student = Student(name, age, student_id, score)
        parent.add_student_to_table(student)
        self.destroy()

class ModifyStudentDialog(tk.Toplevel):
    def __init__(self, parent, student):
        super().__init__(parent)

        self.title("修改学生")

        self.name_label = tk.Label(self, text="姓名")
        self.name_label.pack()

        self.name_entry = tk.Entry(self, text=student.name)
        self.name_entry.pack()

        self.age_label = tk.Label(self, text="年龄")
        self.age_label.pack()

        self.age_entry = tk.Entry(self, text=student.age)
        self.age_entry.pack()

        self.student_id_label = tk.Label(self, text="学号")
        self.student_id_label.pack()

        self.student_id_entry = tk.Entry(self, text=student.student_id)
        self.student_id_entry.pack()

        self.score_label = tk.Label(self, text="成绩")
        self.score_label.pack()

        self.score_entry = tk.Entry(self, text=student.score)
        self.score_entry.pack()

        self.modify_button = tk.Button(self, text="修改", command=self.modify_student)
        self.modify_button.pack()

    def modify_student(self):
        name = self.name_entry.get()
        age = self.age_entry.get()
        student_id = self.student_id_entry.get()
        score = self.score_entry.get()

        if not name or not age or not student_id or not score:
            messagebox.showwarning("警告", "请填写完整信息")
            return

        try:
            age = int(age)
            student_id = int(student_id)
            score = int(score)
        except ValueError:
            messagebox.showerror("错误", "年龄、学号和成绩必须是整数")
            return

        if not 0 <= age <= 150:
            messagebox.showerror("错误", "年龄必须在0至150之间")
            return

        if not 100000 <= student_id <= 999999:
            messagebox.showerror("错误", "学号必须是6位数字")
            return

        if not 0 <= score <= 100:
            messagebox.showerror("错误", "成绩必须在0至100之间")
            return

        student = Student(name, age, student_id, score)
        parent.modify_student_in_table(parent.students.index(self.student), student)
        self.destroy()

class QueryStudentDialog(tk.Toplevel):
    def __init__(self, parent):
        super().__init__(parent)

        self.title("查询学生")

        self.query_label = tk.Label(self, text="查询条件")
        self.query_label.pack()

        self.query_entry = tk.Entry(self)
        self.query_entry.pack()

        self.query_button = tk.Button(self, text="查询", command=self.query_student)
        self.query_button.pack()

        self.result_table = ttk.Treeview(self, columns=("name", "age", "student_id", "score"), show="headings")
        self.result_table.pack()

        self.result_table.heading("name", text="姓名")
        self.result_table.heading("age", text="年龄")
        self.result_table.heading("student_id", text="学号")
        self.result_table.heading("score", text="成绩")

    def query_student(self):
        query = self.query_entry.get()
        results = []

        for student in parent.students:
            if query in student.name or query in str(student.age) or query in str(student.student_id) or query in str(student.score):
                results.append(student)

        for child in self.result_table.get_children():
            self.result_table.delete(child)

        for student in results:
            self.result_table.insert("", "end", values=(student.name, student.age, student.student_id, student.score))