本文介绍了如何通过反应拖放内容?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我需要从此div渲染内容:
I need to render the content from this div:
<div class="col-sm-4">
<ul class="list-group">
<li class="list-group-item"><a href="#">File Reader</a></li>
<li class="list-group-item" ><a href="#">File Move</a></li>
<li class="list-group-item" ><a href="#">Data Base</a></li>
<li class="list-group-item"><a href="#">SAP R3</a></li>
<li class="list-group-item"><a href="#">FTP</a></li>
<li class="list-group-item"><a href="#">SOAP</a></li>
<li class="list-group-item"><a href="#">Rest</a></li>
<li class="list-group-item"><a href="#">Merge</a></li>
<li class="list-group-item"><a href="#">Filter</a></li>
<li class="list-group-item"><a href="#">Transform</a></li>
</ul>
</div>
在拖放操作中,我尝试了很多示例,但似乎无济于事。
Into a Drag and Drop, i tried a lot of examples but nothing seems to work.
现在是我的代码:
import React, { Component } from 'react';
import PropTypes from 'prop-types';
import { DragSource } from 'react-dnd';
import { ItemTypes } from './Constants';
import styles2 from './Styles.css'
import { render } from 'react-dom';
import {DragDropContext} from 'react-dnd';
import HTML5Backend from 'react-dnd-html5-backend';
const styles = {
fontFamily: 'sans-serif',
textAlign: 'center',
};
function collect(connect, monitor) {
return {
connectDragSource: connect.dragSource(),
isDragging: monitor.isDragging()
};
}
function _(id){
return document.getElementById(id);
}
var droppedIn = false;
function drag_start(event) {
_('app_status').innerHTML = "Dragging the "+event.target.getAttribute('id');
event.dataTransfer.dropEffect = "move";
event.dataTransfer.setData("text", event.target.getAttribute('id') );
}
function drag_enter(event) {
_('app_status').innerHTML = "You are dragging over the "+event.target.getAttribute('id');
}
function drag_leave(event) {
_('app_status').innerHTML = "You left the "+event.target.getAttribute('id');
}
function drag_drop(event) {
event.preventDefault(); /* Prevent undesirable default behavior while dropping */
var elem_id = event.dataTransfer.getData("text");
event.target.appendChild( _(elem_id) );
_('app_status').innerHTML = "Dropped "+elem_id+" into the "+event.target.getAttribute('id');
_(elem_id).removeAttribute("draggable");
_(elem_id).style.cursor = "default";
droppedIn = true;
}
function drag_end(event) {
if(droppedIn == false){
_('app_status').innerHTML = "You let the "+event.target.getAttribute('id')+" go.";
}
droppedIn = false;
}
function readDropZone(){
for(var i=0; i < _("drop_zone").children.length; i++){
alert(_("drop_zone").children[i].id+" is in the drop zone");
}
/* Run Ajax request to pass any data to your server */
}
const propTypes = {
text: PropTypes.string.isRequired,
// Injected by React DnD:
isDragging: PropTypes.bool.isRequired,
connectDragSource: PropTypes.func.isRequired
};
class BasicForm extends React.Component {
constructor(props) {
super(props);
this.state = {value: ''};
this.handleChange = this.handleChange.bind(this);
this.handleSubmit = this.handleSubmit.bind(this);
}
render() {
return (
<div style={styles}>
<form onSubmit={this.handleSubmit}>
<div class="container">
<div class="row">
<div class="col-sm-4">
<ul class="list-group">
<li class="list-group-item"><a href="#">File Reader</a></li>
<li class="list-group-item" ><a href="#">File Move</a></li>
<li class="list-group-item" ><a href="#">Data Base</a></li>
<li class="list-group-item"><a href="#">SAP R3</a></li>
<li class="list-group-item"><a href="#">FTP</a></li>
<li class="list-group-item"><a href="#">SOAP</a></li>
<li class="list-group-item"><a href="#">Rest</a></li>
<li class="list-group-item"><a href="#">Merge</a></li>
<li class="list-group-item"><a href="#">Filter</a></li>
<li class="list-group-item"><a href="#">Transform</a></li>
</ul>
</div>
<h2 id="app_status">App status...</h2>
<h1>Drop Zone</h1>
<div id="drop_zone" onDragEnter="drag_enter(event)" onDrop="drag_drop(event)" onDragOver="return false" onDragLeave="drag_leave(event)" className={styles2.drop_zone} ></div>
</div>
</div>
<input type="submit" value="Submit" />
</form>
</div>
);
}
}export default DragDropContext(HTML5Backend)(BasicForm);
在我的控制台上,我收到此错误:预期 onDragEnter
侦听器是一个函数,取而代之的是 string
类型的值。
我在做什么错?
PS:我是React的新手,我尝试了很多示例,所以代码有点大。
On my console i get this error : Expected onDragEnter
listener to be a function, instead got a value of string
type.What i'm doing wrong?PS: I'm new with React, i tried so many examples, so the code is a little bit big.
推荐答案
这是react中列表的基本拖放示例。
This is a basic drag and drop example for list in react. Does not handle the dropping yet, only the dragging and the scroll.
const getWindowScroll = () => {
const doc = document.documentElement;
return (window.pageYOffset || doc.scrollTop) - (doc.clientTop || 0);
}
class App extends React.Component {
setElemRef = ref => {
this.elemRef = ref;
}
initialiseDrag = event => {
const {target, clientY} = event;
const { offsetTop } = target;
const { top } = this.elemRef.getBoundingClientRect();
this.dragStartTop = top - offsetTop;
this.dragStartY = clientY;
window.addEventListener('mousemove', this.startDragging, false);
window.addEventListener('mouseup', this.stopDragging, false);
}
startDragging = ({ clientY }) => {
let newTop = this.dragStartTop + clientY - this.dragStartY + getWindowScroll();
if (newTop < 0) newTop = 0;
this.elemRef.style.transform = `translateY(${newTop}px)`;
this.scrollIfElementBottom(newTop);
}
stopDragging = () => {
window.removeEventListener('mousemove', this.startDragging, false);
window.removeEventListener('mouseup', this.stopDragging, false);
}
scrollIfElementBottom = newTop => {
if (newTop > 30) {
window.scroll({
top: newTop,
behavior: 'smooth'
});
}
if (newTop < 30) {
window.scroll({
top: 0,
behavior: 'smooth'
});
}
};
render(){
return (
<React.Fragment>
<div onMouseDown={this.initialiseDrag} ref={this.setElemRef}>DragMe</div>
<div>List elem</div>
<div>List elem</div>
<div>List elem</div>
<div>List elem</div>
<div>List elem</div>
<div>List elem</div>
<div>List elem</div>
<div>List elem</div>
</React.Fragment>
)
}
}
ReactDOM.render(<App />, document.getElementById('root'));
#root div {
background: gray;
padding: 20px;
margin: 10px;
user-select: none;
cursor: pointer;
border: 1px solid lightgray;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<div id="root"></div>
这篇关于如何通过反应拖放内容?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!