React 19介绍了几个强大的新钩子，这些钩子彻底改变了我们如何处理形式并管理应用程序中的乐观更新。在此博客中，我们将探索USEFormStatus，UseActionState和UseOptimistic-三个挂钩，使我们的React应用程序更加响应且用户友好。 UseFormstatus：增强的形式处理

useformstatus Hook提供了有关表单提交的实时信息，从而更容易创建响应式且易于访问的表单。让我们探索该钩子如何改善React 18的形式处理功能。

示例2：多种形式状态

function SubmitButton() {
  const { pending } = useFormStatus();

  return (
    
      {pending ? 'Submitting...' : 'Submit'}
    
  );
}

function SignupForm() {
  return (
    

示例3：形式验证状态

函数验证status（）{ const {待定，validationErrors} = useformstatus（）; 返回 （

{验证词？.map（（错误，index）=>（（

{error}

）}}

）； } 函数regumtrationform（）{ 返回 （

function FormStatus() {
  const { pending, data, method } = useFormStatus();

  return (
    

      {pending && Submitting via {method}...}
      {!pending && data && Last submission: {new Date().toLocaleString()}}
    
  );
}

function ContactForm() {
  return (
    

函数formProgress（）{ const {待处理，步骤，totalsteps} = useformstatus（）; 返回 （

示例5：文件上传进度

function ValidationStatus() {
  const { pending, validationErrors } = useFormStatus();

  return (
    

      {validationErrors?.map((error, index) => (
        
{error}
      ))}
    
  );
}

function RegistrationForm() {
  return (
    

{ const errors = validateRegistration(formData); if (errors.length) throw errors; await register(formData); }}>

); } 函数uploadprogress（）{ const {待定，progress} = useformstatus（）; 返回 （

{等待&& progress &&（（

USEACTIONSTATE：管理行动结果

function FormProgress() {
  const { pending, step, totalSteps } = useFormStatus();

  return (
    

      





  
  
  Example 5: File Upload Progress




function UploadProgress() {
  const { pending, progress } = useFormStatus();

  return (
    

      {pending && progress && (
        

          





  
  
  useActionState: Managing Action Results


The useActionState hook provides a way to track the state of form actions and server mutations, making it easier to handle success and error states.


  
  
  Example 1: Basic Action State




function SubmissionStatus() {
  const state = useActionState();

  return (
    

      {state.status === 'success' && 
Submission successful!
}
      {state.status === 'error' && 
Error: {state.error.message}
}
    
  );
}

function CommentForm() {
  return (
    
 {
      await submitComment(formData);
    }}>
      
      
      
    
  );
}





  
  
  示例4：行动队列




function ActionHistory() {
  const state = useActionState();

  return (
    

      
Recent Actions
      

        {state.history.map((action, index) => (
          

            {action.type} - {action.timestamp}
            {action.status === 'error' && ` (Failed: ${action.error.message})`}
          
        ))}
      
    
  );
}





  
  
  示例5：动作统计




function RetryableAction() {
  const state = useActionState();

  return (
    

      {state.status === 'error' && (
         state.retry()}
          disabled={state.retrying}
        >
          {state.retrying ? 'Retrying...' : 'Retry'}
        
      )}
    
  );
}





  
  
  UseOptimistic：流畅的UI更新


function ActionQueue() {
  const state = useActionState();

  return (
    

      
Pending Actions
      {state.queue.map((action, index) => (
        

          {action.type} - Queued at {action.queuedAt}
           action.cancel()}>Cancel
        
      ))}
    
  );
}

  
  
  示例1：乐观的待办事项清单




函数todolist（）{
  const [todos，settodos] = usestate（[]）;
  const [Optibistictodos，addoptimistictodo] = useOptimistic（
    毒品，
    （state，newtodo）=> [...状态，newtodo]
  ）；

  异步函数addtodo（formData）{
    const newtodo = {
      id：date.now（），
      文字：formdata.get（'todo'），
      完成：false
    };

    addoptimistictodo（newtodo）;
    等待Savetodo（newtodo）;
  }

  返回 （
    

      

        
        添加todo 
      
      

        {uptistictodos.map（todo =>（（
          
 {todo.text} 
        ）}}
      
    
  ）；
}
function ValidationStatus() {
  const { pending, validationErrors } = useFormStatus();

  return (
    

      {validationErrors?.map((error, index) => (
        
{error}
      ))}
    
  );
}

function RegistrationForm() {
  return (
    
 {
      const errors = validateRegistration(formData);
      if (errors.length) throw errors;
      await register(formData);
    }}>
      
      
      
      
    
  );
}

  
  
  示例2：乐观的按钮




 = usestate（initiallikes）;
  const [opportisticlikes，addoptimisticlike] = useOptimistim（
    喜欢，
    （状态）=>状态1
  ）；

  异步函数handlelike（）{
    addOptimisticLike（）;
    等待着像post（postid）；
  }

  返回 （
    
      {opportisticlikes}喜欢
    
  ）；
}





  
  
  示例3：乐观的评论线程




[2
  const [注释，设定] = usestate（[]）;
  const [Opportisticments，addOptimisticcomment] = useOptimistim（
    评论，
    （状态，新COMMENT）=> [...状态，新COMMENT]
  ）；

  异步功能提交（formdata）{
    const注释= {
      id：date.now（），
      文字：formdata.get（'comment'），
      待处理：是的
    };

    AddOptimisticComment（注释）;
    等待SaveCommant（Postid，评论）；
  }

  返回 （
    

      

        
        注释
      
      {opporpisticcomments.map（comment =>（（
        





  
  
  示例4：乐观的购物车
function TodoList() {
  const [todos, setTodos] = useState([]);
  const [optimisticTodos, addOptimisticTodo] = useOptimistic(
    todos,
    (state, newTodo) => [...state, newTodo]
  );

  async function addTodo(formData) {
    const newTodo = {
      id: Date.now(),
      text: formData.get('todo'),
      completed: false
    };

    addOptimisticTodo(newTodo);
    await saveTodo(newTodo);
  }

  return (
    

      

        
        Add Todo
      
      

        {optimisticTodos.map(todo => (
          
{todo.text}
        ))}
      
    
  );
}





  
  
  示例5：乐观的用户设置




function LikeButton({ postId, initialLikes }) {
  const [likes, setLikes] = useState(initialLikes);
  const [optimisticLikes, addOptimisticLike] = useOptimistic(
    likes,
    (state) => state   1
  );

  async function handleLike() {
    addOptimisticLike();
    await likePost(postId);
  }

  return (
    
      {optimisticLikes} Likes
    
  );
}




记住在应用程序中使用这些挂钩时检查官方的React文档中是否有最新的信息和最佳实践。

快乐编码！