React初学者问题:Textfield失去了对更新的关注 [英] React Beginner Question: Textfield Losing Focus On Update
问题描述
我编写了一个组件，该组件应该列出一堆带有相应文本字段的复选框.当您单击复选框时，或在字段中输入内容是为了更新状态.
I wrote a component that is supposed to list out a bunch of checkboxes with corresponding textfields. When you click on the checkboxes, or type in the fields it's meant to update state.
该文本框可以正常工作，但是当我在字段中键入内容时，它会更新状态为ok，但是只要单击键盘，我就会失去焦点.
The textbox is working ok, but when I type in the fields, it updates state ok, but I lose focus whenever I tap the keyboard.
我意识到这可能是由于没有设置键，所以我向所有内容添加了键，但仍然失去了重点.有一次我尝试在事件中添加stopPropegation，因为我认为这可能会引起问题?我不确定...仍在学习...似乎没有用，所以我也删除了该部分.
I realized this is probably due to not having keys set, so I added keys to everything but it still is losing focus. At one point I tried adding in stopPropegation on my events because I thought maybe that was causing an issue?? I'm not sure.. still learning...didn't seem to work so I removed that part too.
似乎仍然无法弄清楚是什么原因导致了它失去焦点……有人对此问题有任何建议/解决方案吗?
Still can't seem to figure out what is causing it to lose focus... does anyone have any advice/solves for this issue?
我合并了我的代码，并切掉了不必要的部分，以使其更易于阅读.有三个相关的JS文件..请参见以下内容:
I consolidated my code and cut out the unnecessary bits to make it easier to read. There are three relevant JS files.. please see below:
我仍然是初学者/学习者，因此，如果您有关于此代码任何部分的有用建议，请随时提供.谢谢！
I'm still a beginner/learning so if you have useful advice related to any part of this code, feel free to offer. Thanks!
App.js
import React, { Component } from 'react';
import Form from './Form'
class App extends Component {
constructor() {
super();
this.state = {
mediaDeliverables: [
{label: 'badf', checked: false, quantity:''},
{label: 'adfadf', checked: false, quantity:''},
{label: 'adadf', checked: false, quantity:''},
{label: 'addadf', checked: false, quantity:''},
{label: 'adfdes', checked: false, quantity:''},
{label: 'hghdgs', checked: false, quantity:''},
{label: 'srtnf', checked: false, quantity:''},
{label: 'xfthd', checked: false, quantity:''},
{label: 'sbnhrr', checked: false, quantity:''},
{label: 'sfghhh', checked: false, quantity:''},
{label: 'sssddrr', checked: false, quantity:''}
]
}
}
setMediaDeliverable = (value, index) => {
let currentState = this.getStateCopy();
currentState.mediaDeliverables[index] = value;
this.setState(currentState);
}
getStateCopy = () => Object.assign({}, this.state);
render() {
return (
<div className="App">
<Form
key="mainForm"
mediaDeliverablesOptions={this.state.mediaDeliverables}
setMediaDeliverable={this.setMediaDeliverable}
/>
</div>
);
}
}
export default App;
Form.js
import React from 'react';
import { makeStyles, useTheme } from '@material-ui/core/styles';
import FormControl from '@material-ui/core/FormControl';
import FormLabel from '@material-ui/core/FormLabel';
import FormGroup from '@material-ui/core/FormGroup';
import FormControlLabel from '@material-ui/core/FormControlLabel';
import Checkbox from '@material-ui/core/Checkbox';
import MediaDeliverablesCheckBox from './MediaDeliverablesCheckBox';
const useStyles = makeStyles(theme => ({
container: {
display: 'inline-block',
flexWrap: 'wrap',
},
root: {
display: 'inline-block',
flexWrap: 'wrap',
maxWidth: 600,
textAlign: 'left',
},
extendedIcon: {
marginRight: theme.spacing(1),
},
formControl: {
margin: theme.spacing(1),
minWidth: 120,
maxWidth: 300,
},
textField: {
marginLeft: theme.spacing(1),
marginRight: theme.spacing(1),
width: 370,
},
dense: {
marginTop: 19,
},
chips: {
display: 'flex',
flexWrap: 'wrap',
},
chip: {
margin: 2,
},
noLabel: {
marginTop: theme.spacing(3),
},
}));
const ITEM_HEIGHT = 48;
const ITEM_PADDING_TOP = 8;
const MenuProps = {
PaperProps: {
style: {
maxHeight: ITEM_HEIGHT * 4.5 + ITEM_PADDING_TOP,
width: 250,
},
},
};
function getStyles(name, accountName, theme) {
// console.log('>> [form.js] (getStyles) ',accountName)
return {
fontWeight:
accountName.indexOf(name) === -1
? theme.typography.fontWeightRegular
: theme.typography.fontWeightMedium,
};
}
export default function Form(props) {
const mediaDeliverablesOptions = props.mediaDeliverablesOptions;
const classes = useStyles();
const theme = useTheme();
const CheckboxGroup = ({ values, label, onChange }) => (
<FormControl component="fieldset">
<FormLabel component="legend">{label}</FormLabel>
<FormGroup>
{values.map((value, index) => (
<FormControlLabel
key={index}
control={
<Checkbox
checked={value.checked}
onChange={onChange(index)}
/>
}
label={value.label}
/>
))}
</FormGroup>
</FormControl>
);
const MediaDeliverableCheckBoxList = ({values, label}) => (
<FormControl component="fieldset">
<FormLabel component="legend">{label}</FormLabel>
<FormGroup>
{values.map((value, index) => (
<MediaDeliverablesCheckBox
key={index}
mediaDeliverablesOptions={value}
onMediaDeliverableChange={onMediaDeliverableChange(index)}
/>
))}
</FormGroup>
</FormControl>
);
const onCheckBoxChange = index => ({ target: { checked } }) => {
const newValues = [...values];
const value = values[index];
newValues[index] = { ...value, checked };
props.setDesignOrDigital(newValues);
};
const onMediaDeliverableChange = index => (deliverableData, e) => {
props.setMediaDeliverable(deliverableData, index);
}
return (
<div className={classes.root}>
<MediaDeliverableCheckBoxList
label="Please Choose Deliverables:"
values={mediaDeliverablesOptions}
key="media-deliverable-checkbox-list"
/>
</div>
);
}
MediaDeliverablesCheckbox.js
MediaDeliverablesCheckbox.js
import React from 'react';
import Checkbox from '@material-ui/core/Checkbox';
import { makeStyles, useTheme } from '@material-ui/core/styles';
import FormControl from '@material-ui/core/FormControl';
import FormLabel from '@material-ui/core/FormLabel';
import FormGroup from '@material-ui/core/FormGroup';
import FormControlLabel from '@material-ui/core/FormControlLabel';
import TextField from '@material-ui/core/TextField';
export default function MediaDeliverablesCheckBox(props) {
let deliverableData = Object.assign({}, props.mediaDeliverablesOptions);
const onCheckBoxChange = (e) => {
deliverableData.checked = e.target.checked;
props.onMediaDeliverableChange(deliverableData, e);
}
const onQuantityChange = (e) => {
deliverableData.quantity = e.target.value;
props.onMediaDeliverableChange(deliverableData, e);
}
const CheckboxGroup = ({ value, label }) => (
<FormControl component="fieldset">
<FormGroup>
<FormControlLabel
control={
<Checkbox
key={props.index}
checked={value.checked}
onChange={onCheckBoxChange}
/>
}
label={label}
/>
</FormGroup>
</FormControl>
);
return(
<div className="MediaDeliverablesCheckBox">
<CheckboxGroup
key={props.index}
label={props.mediaDeliverablesOptions.label}
value={props.mediaDeliverablesOptions}
/>
<TextField
key={'tf'+props.index}
id={'quantity-'+props.index}
label="Quantity"
placeholder="How many do you need?"
multiline
variant="outlined"
value={props.mediaDeliverablesOptions.quantity}
onChange={onQuantityChange}
fullWidth
/>
</div>
);
}
根据Ryan C的建议编辑更新了Form.js.
Updated Form.js based on recommended edits by Ryan C.
import React from 'react';
import { makeStyles, useTheme } from '@material-ui/core/styles';
import FormControl from '@material-ui/core/FormControl';
import FormLabel from '@material-ui/core/FormLabel';
import FormGroup from '@material-ui/core/FormGroup';
import FormControlLabel from '@material-ui/core/FormControlLabel';
import Checkbox from '@material-ui/core/Checkbox';
import MediaDeliverablesCheckBox from './MediaDeliverablesCheckBox';
const useStyles = makeStyles(theme => ({
container: {
display: 'inline-block',
flexWrap: 'wrap',
},
root: {
display: 'inline-block',
flexWrap: 'wrap',
maxWidth: 600,
textAlign: 'left',
},
extendedIcon: {
marginRight: theme.spacing(1),
},
formControl: {
margin: theme.spacing(1),
minWidth: 120,
maxWidth: 300,
},
textField: {
marginLeft: theme.spacing(1),
marginRight: theme.spacing(1),
width: 370,
},
dense: {
marginTop: 19,
},
chips: {
display: 'flex',
flexWrap: 'wrap',
},
chip: {
margin: 2,
},
noLabel: {
marginTop: theme.spacing(3),
},
}));
const ITEM_HEIGHT = 48;
const ITEM_PADDING_TOP = 8;
const MenuProps = {
PaperProps: {
style: {
maxHeight: ITEM_HEIGHT * 4.5 + ITEM_PADDING_TOP,
width: 250,
},
},
};
function getStyles(name, accountName, theme) {
return {
fontWeight:
accountName.indexOf(name) === -1
? theme.typography.fontWeightRegular
: theme.typography.fontWeightMedium,
};
}
// Failed to compile
// ./src/Form.js
// Line 86: Parsing error: Unexpected token, expected ","
// 84 |
// 85 | const MediaDeliverableCheckBoxList = ({values, label, onMediaDeliverableChange}) => (
// > 86 | {values.map((value, index) => (
// | ^
// 87 | <MediaDeliverablesCheckBox
// 88 | key={index}
// 89 | index={index}
// This error occurred during the build time and cannot be dismissed.
const MediaDeliverableCheckBoxList = ({values, label, onMediaDeliverableChange}) => (
{values.map((value, index) => (
<MediaDeliverablesCheckBox
key={index}
index={index}
mediaDeliverablesOptions={value}
onMediaDeliverableChange={onMediaDeliverableChange(index)}
/>
))}
);
export default function Form(props) {
const mediaDeliverablesOptions = props.mediaDeliverablesOptions;
const classes = useStyles();
const theme = useTheme();
const CheckboxGroup = ({ values, label, onChange }) => (
<FormControl component="fieldset">
<FormLabel component="legend">{label}</FormLabel>
<FormGroup>
{values.map((value, index) => (
<FormControlLabel
key={index}
control={
<Checkbox
checked={value.checked}
onChange={onChange(index)}
/>
}
label={value.label}
/>
))}
</FormGroup>
</FormControl>
);
const onCheckBoxChange = index => ({ target: { checked } }) => {
const newValues = [...values];
const value = values[index];
newValues[index] = { ...value, checked };
props.setDesignOrDigital(newValues);
};
const onMediaDeliverableChange = index => (deliverableData, e) => {
props.setMediaDeliverable(deliverableData, index);
}
return (
<div className={classes.root}>
<MediaDeliverableCheckBoxList
onMediaDeliverableChange={onMediaDeliverableChange}
/>
</div>
);
}
推荐答案
我看到两个主要问题:
- 您如何定义不同的组件(嵌套组件类型)
- 不将索引道具传递给期望它的组件
您具有以下结构(省略了与我的观点不直接相关的详细信息):
You have the following structure (leaving out details that are not directly related to my point):
export default function Form(props) {
const onMediaDeliverableChange = index => (deliverableData, e) => {
props.setMediaDeliverable(deliverableData, index);
}
const MediaDeliverableCheckBoxList = ({values, label}) => (
<FormGroup>
{values.map((value, index) => (
<MediaDeliverablesCheckBox key={index} onMediaDeliverableChange={onMediaDeliverableChange(index)}/>
))}
</FormGroup>
);
return (
<MediaDeliverableCheckBoxList/>
);
}
函数MediaDeliverableCheckBoxList表示用于呈现<MediaDeliverableCheckBoxList/>元素的组件类型.每当由于道具或状态改变而重新渲染Form时，React都会重新渲染其子代.如果特定子项的组件类型相同(如果指定，还加上一些其他条件，例如key相同)，则它将更新现有的DOM节点.如果特定子项的组件类型为不同，则相应的DOM节点将被删除，并将新的DOM节点添加到DOM.
The function MediaDeliverableCheckBoxList represents the component type used to render the <MediaDeliverableCheckBoxList/> element. Whenever Form is re-rendered due to props or state changing, React will re-render its children. If the component type of a particular child is the same (plus some other criteria such as key being the same if specified), then it will update the existing DOM node(s). If the component type of a particular child is different, then the corresponding DOM nodes will be removed and new ones added to the DOM.
通过在Form函数中的 in 中定义MediaDeliverableCheckBoxList组件类型，使每个渲染上的组件类型都不同.这将导致替换所有DOM节点，而不仅仅是更新它们，并且当删除之前具有焦点的DOM节点时，将导致焦点消失.这也会导致性能大大降低.
By defining the MediaDeliverableCheckBoxList component type within the Form function, you are causing that component type to be different on every render. This will cause all of the DOM nodes to be replaced rather than just updated and this will cause the focus to go away when the DOM node that previously had focus gets removed. It will also cause performance to be considerably worse.
您可以通过以下方式解决此问题:将组件类型移到Form函数之外，然后添加所需的其他附加道具(例如onMediaDeliverableChange)来传达Form内部已知的上下文.您还需要将索引作为道具传递给MediaDeliverablesCheckBox，因为它正在使用它.
You can fix this by moving this component type outside of the Form function and then adding any additional props that are needed (e.g. onMediaDeliverableChange) to convey the context known inside of Form. You also need to pass index as a prop to MediaDeliverablesCheckBox since it is using it.
const MediaDeliverableCheckBoxList = ({values, label, onMediaDeliverableChange}) => (
<FormGroup>
{values.map((value, index) => (
<MediaDeliverablesCheckBox key={index} index={index} onMediaDeliverableChange={onMediaDeliverableChange(index)}/>
))}
</FormGroup>
);
export default function Form(props) {
const onMediaDeliverableChange = index => (deliverableData, e) => {
props.setMediaDeliverable(deliverableData, index);
}
return (
<MediaDeliverableCheckBoxList onMediaDeliverableChange={onMediaDeliverableChange}/>
);
}
CheckboxGroup和可能的其他组件也有相同的问题.
You have this same issue with CheckboxGroup and possibly other components as well.
这篇关于React初学者问题:Textfield失去了对更新的关注的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
