使用useContext钩子函数实现在React中添加和删除数据，以及对数量进行计数。

1. 创建并导出一个上下文对象：

import { createContext } from 'react';

export interface Data {
  id: number;
  name: string;
}

export interface ContextProps {
  data: Data[];
  addData: (name: string) => void;
  removeData: (id: number) => void;
  count: number;
}

export const AppContext = createContext({
  data: [],
  addData: () => {},
  removeData: () => {},
  count: 0,
});

2. 创建一个包含数据和函数的提供程序，并引入上下文对象：

import React, { useState } from 'react';
import { AppContext, Data, ContextProps } from './AppContext';

interface Props {
  children: React.ReactNode;
}

const AppProvider = ({ children }: Props) => {
  const [data, setData] = useState([]);
  const [count, setCount] = useState(0);

  const addData = (name: string) => {
    const newData: Data = {
      id: data.length + 1,
      name,
    };

    setData([...data, newData]);
    setCount(count + 1);
  };

  const removeData = (id: number) => {
    const updatedData = data.filter(item => item.id !== id);
    setData(updatedData);
    setCount(count - 1);
  };

  const contextValue: ContextProps = {
    data,
    addData,
    removeData,
    count,
  };

  return (
    
      {children}
    
  );
};

export default AppProvider;

3. 在应用程序中使用提供程序包装组件：

import React from 'react';
import AppProvider from './AppProvider';
import DataList from './DataList';
import DataForm from './DataForm';

const App = () => {
  return (
    
      
My App
      
  );
};

export default App;

4. 在子组件中使用useContext钩子函数，来获取所需的数据和函数：

import React, { useContext } from 'react';
import { AppContext } from './AppContext';

const DataList = () => {
  const { data, removeData } = useContext(AppContext);

  return (
    

      <