地图中每个元素的 connectDragSource（拖放：React DnD）

Question

如何使每个项目都可以放置？ 当map() 函数返回新数组时，我决定将connectDragSource 传递给该方法，但我仍然返回 droppable Aray insted droppable Each Item（形状）

for..in, forEach, for..of 也没有得到想要的结果

有人解决了这个问题吗？

import React, { Component } from "react";
import { Segment, Icon } from "semantic-ui-react";
import { DragSource } from "react-dnd";
import ShapeItem from "./ShapeItem";

class Shapes extends Component {

  displayShapes = (shapes, connectDragSource) =>
    shapes.length > 0 &&
    shapes.map((shape) =>
      connectDragSource(
        <div key={shape.id}>
          <Segment>
            <Icon name={shape.name} size={shape.size} color={shape.color} />
          </Segment>
        </div>
      )
    );

  render() {
    const { shapes, connectDragSource} = this.props;
    return (
      <div>
        {this.displayShapes(shapes, connectDragSource)}
      </div>
    );
  }
}

const spec = {
  beginDrag(props) {
    return {
      shapeId: props.shapes.id
    };
  }
};

const collect = (connect, monitor) => ({
  connectDragSource: connect.dragSource(spec),
  isDragging: monitor.isDragging()
});

export default DragSource("shape", spec, collect)(Shapes);

至于文档http://react-dnd.github.io 仅找到以下内容：将元素作为可拖动节点。为此，请将渲染函数中的任何element 替换为this.props.connectDragSource(element)。

Answer 1

您可能希望创建一个单独的组件来呈现每个项目并使其成为拖动源。您还需要从规范中的 canDrag 函数返回 true。

免责声明：我没有测试过下面的代码。

shapes.js

import React, { Component } from "react";
import Item from './item.js';

class Shapes extends Component {    
    render() {
        const { shapes } = this.props;
        return (
            <div>
                {
                    shapes.length > 0 && 
                    shapes.map((shape) => <Item key={shape.id} shape={shape} />)
                }
            </div>
        );
    }
}

export default Shapes;

item.js

import React, { Component } from "react";
import { Segment, Icon } from "semantic-ui-react";
import { DragSource } from "react-dnd";

class Item extends Component {    
    render() {
        const { shape, connectDragSource} = this.props;
        return connectDragSource(
            <div>
                 <Segment>
                     <Icon name={shape.name} size={shape.size} color={shape.color} />
                 </Segment>
            </div>
        )
    }
}

const spec = {
    beginDrag(props) {
        return {
            shapeId: props.shapes.id
        };
    },
    canDrag(props, monitor) {
        return true;
    },
    endDrag(props, monitor) {
        console.log("You dropped .... into " + monitor.getDropResult());
    }
};

const collect = (connect, monitor) => ({
  connectDragSource: connect.dragSource(spec),
  isDragging: monitor.isDragging()
});

export default DragSource("shape", spec, collect)(Item);