Java实现待办事项应用教程

public class TodoItem {
    private String title;
    private boolean completed;
public TodoItem(String title) {
    this.title = title;
    this.completed = false;
}

public String getTitle() {
    return title;
}

public boolean isCompleted() {
    return completed;
}

public void setCompleted(boolean completed) {
    this.completed = completed;
}

@Override
public String toString() {
    return (completed ? "[✓] " : "[ ] ") + title;
}
}

import java.util.ArrayList;
import java.util.List;
public class TodoList {
private List items;
public TodoList() {
    items = new ArrayList<>();
}

public void add(String title) {
    items.add(new TodoItem(title));
}

public void remove(int index) {
    if (index >= 0 && index < items.size()) {
        items.remove(index);
    } else {
        System.out.println("无效的序号！");
    }
}

public void toggleComplete(int index) {
    if (index >= 0 && index < items.size()) {
        TodoItem item = items.get(index);
        item.setCompleted(!item.isCompleted());
    } else {
        System.out.println("无效的序号！");
    }
}

public void display() {
    if (items.isEmpty()) {
        System.out.println("暂无待办事项。");
    } else {
        for (int i = 0; i < items.size(); i++) {
            System.out.println((i + 1) + ". " + items.get(i));
        }
    }
}
}

import java.util.Scanner;
public class Main {
public static void main(String[] args) {
TodoList todoList = new TodoList();
Scanner scanner = new Scanner(System.in);
String command;
    System.out.println("欢迎使用Todo待办事项应用！");

    while (true) {
        System.out.println("\n可用操作：add(添加), list(查看), complete(完成), remove(删除), quit(退出)");
        System.out.print("请输入命令: ");
        command = scanner.nextLine().trim().toLowerCase();

        switch (command) {
            case "add":
                System.out.print("请输入任务内容: ");
                String title = scanner.nextLine();
                todoList.add(title);
                System.out.println("任务已添加。");
                break;

            case "list":
                todoList.display();
                break;

            case "complete":
                System.out.print("请输入要标记完成的任务编号: ");
                try {
                    int index = Integer.parseInt(scanner.nextLine()) - 1;
                    todoList.toggleComplete(index);
                    System.out.println("任务状态已更新。");
                } catch (NumberFormatException e) {
                    System.out.println("请输入有效数字。");
                }
                break;

            case "remove":
                System.out.print("请输入要删除的任务编号: ");
                try {
                    int index = Integer.parseInt(scanner.nextLine()) - 1;
                    todoList.remove(index);
                    System.out.println("任务已删除。");
                } catch (NumberFormatException e) {
                    System.out.println("请输入有效数字。");
                }
                break;

            case "quit":
                System.out.println("再见！");
                scanner.close();
                return;

            default:
                System.out.println("未知命令，请重新输入。");
        }
    }
}
}