25.1 项目目标

在第24章的 月份筛选功能 基础上，新增：

1. 类别输入：记录时选择支出/收入类别，例如：餐饮、交通、购物、工资、理财等
2. 类别统计：计算选定月份的各类别总额
3. 类别图表：生成饼图，展示各类别所占比例

25.2 界面设计

• 在 添加记录区 新增 类别下拉框，收入和支出都有对应类别。
• 在 统计功能区 新增按钮 → “类别统计”。
• 点击按钮后，显示 饼图，展示该月的各类别收支比例。

25.3 核心代码

下面是在第24章的 BudgetApp 基础上修改后的核心实现：

import tkinter as tk
from tkinter import ttk, messagebox
import sqlite3
from datetime import datetime
import matplotlib.pyplot as plt
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

class BudgetApp:
    def __init__(self, root):
        self.root = root
        self.root.title("记账本（类别统计版）")
        self.root.geometry("850x600")

        # 数据库
        self.conn = sqlite3.connect("budget.db")
        self.cursor = self.conn.cursor()
        self.create_table()

        # 输入区
        frame_input = tk.Frame(self.root)
        frame_input.pack(pady=10)

        tk.Label(frame_input, text="日期(YYYY-MM-DD):").grid(row=0, column=0, padx=5)
        self.entry_date = tk.Entry(frame_input, width=12)
        self.entry_date.grid(row=0, column=1, padx=5)
        self.entry_date.insert(0, datetime.now().strftime("%Y-%m-%d"))

        tk.Label(frame_input, text="收支类型:").grid(row=0, column=2, padx=5)
        self.combo_type = ttk.Combobox(frame_input, values=["收入", "支出"], width=8)
        self.combo_type.grid(row=0, column=3, padx=5)
        self.combo_type.current(0)
        self.combo_type.bind("<<ComboboxSelected>>", self.update_categories)

        tk.Label(frame_input, text="类别:").grid(row=0, column=4, padx=5)
        self.combo_category = ttk.Combobox(frame_input, values=[], width=10)
        self.combo_category.grid(row=0, column=5, padx=5)
        self.update_categories()  # 初始化类别

        tk.Label(frame_input, text="金额:").grid(row=0, column=6, padx=5)
        self.entry_amount = tk.Entry(frame_input, width=10)
        self.entry_amount.grid(row=0, column=7, padx=5)

        tk.Label(frame_input, text="备注:").grid(row=0, column=8, padx=5)
        self.entry_note = tk.Entry(frame_input, width=15)
        self.entry_note.grid(row=0, column=9, padx=5)

        tk.Button(frame_input, text="添加记录", command=self.add_record).grid(row=0, column=10, padx=10)

        # 月份筛选区
        frame_month = tk.Frame(self.root)
        frame_month.pack(pady=5)

        tk.Label(frame_month, text="选择月份:").pack(side=tk.LEFT, padx=5)

        self.combo_month = ttk.Combobox(frame_month, values=self.get_months(), width=10)
        self.combo_month.pack(side=tk.LEFT, padx=5)
        self.combo_month.set(datetime.now().strftime("%Y-%m"))

        tk.Button(frame_month, text="查询", command=self.load_records).pack(side=tk.LEFT, padx=10)

        # 表格
        self.tree = ttk.Treeview(self.root, columns=("id", "date", "type", "category", "amount", "note"), show="headings")
        self.tree.heading("id", text="ID")
        self.tree.heading("date", text="日期")
        self.tree.heading("type", text="收支类型")
        self.tree.heading("category", text="类别")
        self.tree.heading("amount", text="金额")
        self.tree.heading("note", text="备注")

        self.tree.column("id", width=50, anchor="center")
        self.tree.column("date", width=100, anchor="center")
        self.tree.column("type", width=80, anchor="center")
        self.tree.column("category", width=100, anchor="center")
        self.tree.column("amount", width=80, anchor="center")
        self.tree.column("note", width=200, anchor="w")

        self.tree.pack(fill=tk.BOTH, expand=True, padx=10, pady=10)

        # 操作按钮
        frame_btn = tk.Frame(self.root)
        frame_btn.pack(pady=5)

        tk.Button(frame_btn, text="删除记录", command=self.delete_record).pack(side=tk.LEFT, padx=10)
        tk.Button(frame_btn, text="统计收支", command=self.show_summary).pack(side=tk.LEFT, padx=10)
        tk.Button(frame_btn, text="收支饼图", command=self.show_pie_chart).pack(side=tk.LEFT, padx=10)
        tk.Button(frame_btn, text="收支趋势图", command=self.show_line_chart).pack(side=tk.LEFT, padx=10)
        tk.Button(frame_btn, text="类别统计图", command=self.show_category_chart).pack(side=tk.LEFT, padx=10)

        # 初始加载
        self.load_records()

    def create_table(self):
        self.cursor.execute("""
        CREATE TABLE IF NOT EXISTS records (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            date TEXT,
            type TEXT,
            category TEXT,
            amount REAL,
            note TEXT
        )
        """)
        self.conn.commit()

    def update_categories(self, event=None):
        """根据收支类型更新类别"""
        if self.combo_type.get() == "收入":
            categories = ["工资", "奖金", "理财", "其他"]
        else:
            categories = ["餐饮", "交通", "购物", "住房", "娱乐", "医疗", "其他"]
        self.combo_category["values"] = categories
        self.combo_category.current(0)

    def add_record(self):
        date = self.entry_date.get()
        type_ = self.combo_type.get()
        category = self.combo_category.get()
        try:
            amount = float(self.entry_amount.get())
        except ValueError:
            messagebox.showerror("错误", "金额必须是数字")
            return
        note = self.entry_note.get()

        self.cursor.execute("INSERT INTO records (date, type, category, amount, note) VALUES (?, ?, ?, ?, ?)",
                            (date, type_, category, amount, note))
        self.conn.commit()
        self.load_records()

        self.entry_amount.delete(0, tk.END)
        self.entry_note.delete(0, tk.END)

    def get_months(self):
        self.cursor.execute("SELECT DISTINCT substr(date, 1, 7) FROM records ORDER BY date DESC")
        months = [row[0] for row in self.cursor.fetchall()]
        if not months:
            months = [datetime.now().strftime("%Y-%m")]
        return months

    def load_records(self):
        for row in self.tree.get_children():
            self.tree.delete(row)

        month = self.combo_month.get()
        self.cursor.execute("SELECT * FROM records WHERE substr(date,1,7)=? ORDER BY date DESC", (month,))
        for row in self.cursor.fetchall():
            self.tree.insert("", tk.END, values=row)

    def delete_record(self):
        selected = self.tree.selection()
        if not selected:
            messagebox.showwarning("提示", "请选择要删除的记录")
            return

        record_id = self.tree.item(selected[0])["values"][0]
        self.cursor.execute("DELETE FROM records WHERE id=?", (record_id,))
        self.conn.commit()
        self.load_records()

    def show_summary(self):
        month = self.combo_month.get()
        self.cursor.execute("SELECT type, SUM(amount) FROM records WHERE substr(date,1,7)=? GROUP BY type", (month,))
        result = self.cursor.fetchall()

        income = sum(r[1] for r in result if r[0] == "收入")
        expense = sum(r[1] for r in result if r[0] == "支出")

        messagebox.showinfo("统计结果", f"{month} 收支情况：\n总收入: {income} 元\n总支出: {expense} 元\n结余: {income - expense} 元")

    def show_pie_chart(self):
        month = self.combo_month.get()
        self.cursor.execute("SELECT type, SUM(amount) FROM records WHERE substr(date,1,7)=? GROUP BY type", (month,))
        result = self.cursor.fetchall()

        if not result:
            messagebox.showwarning("提示", "没有数据可显示")
            return

        labels = [r[0] for r in result]
        amounts = [r[1] for r in result]

        fig, ax = plt.subplots()
        ax.pie(amounts, labels=labels, autopct="%1.1f%%", startangle=90)
        ax.set_title(f"{month} 收支比例")

        win = tk.Toplevel(self.root)
        win.title("收支饼图")
        canvas = FigureCanvasTkAgg(fig, master=win)
        canvas.draw()
        canvas.get_tk_widget().pack(fill=tk.BOTH, expand=True)

    def show_line_chart(self):
        month = self.combo_month.get()
        self.cursor.execute("SELECT date, type, SUM(amount) FROM records WHERE substr(date,1,7)=? GROUP BY date, type ORDER BY date", (month,))
        result = self.cursor.fetchall()

        if not result:
            messagebox.showwarning("提示", "没有数据可显示")
            return

        dates = sorted(set(r[0] for r in result))
        income_data, expense_data = [], []

        for d in dates:
            income = sum(r[2] for r in result if r[0] == d and r[1] == "收入")
            expense = sum(r[2] for r in result if r[0] == d and r[1] == "支出")
            income_data.append(income)
            expense_data.append(expense)

        fig, ax = plt.subplots()
        ax.plot(dates, income_data, marker="o", label="收入")
        ax.plot(dates, expense_data, marker="o", label="支出")
        ax.set_title(f"{month} 收支趋势图")
        ax.set_xlabel("日期")
        ax.set_ylabel("金额")
        ax.legend()
        plt.xticks(rotation=45)

        win = tk.Toplevel(self.root)
        win.title("收支趋势图")
        canvas = FigureCanvasTkAgg(fig, master=win)
        canvas.draw()
        canvas.get_tk_widget().pack(fill=tk.BOTH, expand=True)

    def show_category_chart(self):
        """按类别统计并绘制饼图"""
        month = self.combo_month.get()
        self.cursor.execute("SELECT category, SUM(amount) FROM records WHERE substr(date,1,7)=? GROUP BY category", (month,))
        result = self.cursor.fetchall()

        if not result:
            messagebox.showwarning("提示", "没有数据可显示")
            return

        labels = [r[0] for r in result]
        amounts = [r[1] for r in result]

        fig, ax = plt.subplots()
        ax.pie(amounts, labels=labels, autopct="%1.1f%%", startangle=90)
        ax.set_title(f"{month} 各类别占比")

        win = tk.Toplevel(self.root)
        win.title("类别统计图")
        canvas = FigureCanvasTkAgg(fig, master=win)
        canvas.draw()
        canvas.get_tk_widget().pack(fill=tk.BOTH, expand=True)

    def __del__(self):
        self.conn.close()

if __name__ == "__main__":
    root = tk.Tk()
    app = BudgetApp(root)
    root.mainloop()

25.4 功能演示

1. 录入一条支出：2025-09-01 支出 餐饮 45 午餐
2. 录入一条支出：2025-09-02 支出 交通 10 地铁
3. 录入一条收入：2025-09-05 收入 工资 5000
4. 点击“类别统计图” → 显示 当月各类别占比饼图

25.5 小结

• 学会了根据收支类型动态更新类别下拉框
• 在数据库中新增 category 列，用于存储类别信息
• 实现了 类别统计图表，让财务分析更直观