我有以下React组件(使用hooks
),它列出了多个Tasks
作为下拉列表。从列表中选择一个项目后,我要显示一个Update
表单。仅当第一次选择一个项目时,此功能才有效。当我选择一个新项目时,什么也没发生(尽管console.log(e.target.value);
打印正确的值)。我将所选任务的ID存储在st_taskId
中。
我想知道您是否在下面的代码中看到任何问题:
const ManageReviewTasks = props => {
const reviewRoundId = props.match.params.reviewRoundId;
const [st_taskId, set_taskId] = useState();
useEffect(() => {
if (props.loading == false && st_taskId == null)
props.fetchReviewTasksByReviewRound(reviewRoundId);
}, [reviewRoundId, st_taskId]);
if (props.loading == true) {
return <div>Loading...</div>;
}
return (
<>
{props.reviewTasks && (
<div>
<h3>Configure the Review Tasks</h3>
<br />
{
<div>
<div>
<h4>
Tasks for <span className="font-italic">students receiving</span> feedback:
</h4>
<select
className="form-control"
onChange={e => {
e.preventDefault();
console.log(e.target.value);
set_taskId(e.target.value);
}}>
<option>--SELECT--</option>
{Object.keys(props.reviewTasks).map(id => {
const task = props.reviewTasks[id];
{
if (task.isForStudent) {
return (
<option key={id} id={id} value={id}>
{task.title}
</option>
);
}
}
})}
</select>
</div>
{props.reviewTasks[st_taskId] && (
<UpdateReviewTaskForm task={props.reviewTasks[st_taskId]} />
)}
</div>
}
</div>
)}
</>
);
};
下面是UpdateReviewTaskForm
组件的代码:
const UpdateReviewTaskForm = (props) => {
const [st_Title, set_Title] = useState(props.task.title);
const [st_Description, set_Description] = useState(RichTextEditor.createValueFromString(props.task.description, 'html'));
const [st_startDate, set_startDate] = useState(new Date(props.task.startDate.replace('-', '/')));
const [st_DueDate, set_DueDate] = useState(new Date(props.task.dueDate.replace('-', '/')));
const handleCancelClick = (event) => {
event.preventDefault();
history.goBack();
}
const onSubmit_saveTask = (e) => {
e.preventDefault();
props.updateReviewTask({
Id: props.task.id,
Title: st_Title,
Description: st_Description.toString('html'),
StartDate: format(st_startDate, 'DD/MM/YYYY'),
DueDate: format(st_DueDate, 'DD/MM/YYYY'),
})
}
if (props.loading)
return <div>Updating...</div>
return (
<div>
<br/>
<br/>
<div className="p-3 bg-light">
<h3 className="text-info">Update the Task:</h3>
{
props.task &&
<form onSubmit={onSubmit_saveTask}>
<div className="form-group">
<label>Enter the title</label>
<input
//placeholder="Enter a title..."
value={st_Title}
onChange={(event) => { set_Title(event.target.value) }}
className="form-control" />
</div>
<div className="form-group">
<label>Enter a description for the assessment</label>
<RichTextEditor
value={st_Description}
onChange={set_Description}
/>
</div>
<div className="form-group">
<label>Start date to start: </label>
<DatePicker
className="form-control"
selected={st_startDate}
onChange={(date) => set_startDate(date)}
/>
</div>
<div className="form-group">
<label>Due date to complete: </label>
<DatePicker
className="form-control"
selected={st_DueDate}
onChange={(date) => set_DueDate(date)}
/>
</div>
<br />
<button type="submit" className="btn btn-primary">Submit</button>
<button type="reset" className="btn btn-light" onClick={handleCancelClick}>Cancel</button>
</form>
}
</div>
</div>
)
}
答案 0 :(得分:1)
由于您正在UpdateReviewTaskForm
中使用内部状态,即使该组件第二次重新渲染,其状态也不会重置(例如,恢复为默认值props.task.title
)。
强制重置状态的一种方法是在key
中使用UpdateReviewTaskForm
道具,如下所示:
{props.reviewTasks[st_taskId] && (
<UpdateReviewTaskForm key={st_taskId} task={props.reviewTasks[st_taskId]} />
)}
另一种方法是在useEffect
更改时在UpdateReviewTaskForm
内使用props.task
运行
useEffect(() => {
// reset the state here
}, [props.task])