Question

如何使每个项目都是可拖放的？当map()函数返回新数组时，我决定将connectDragSource传递到方法中，但是我仍然返回可投放的Aray 插入的可投放的每个项目（形状）

for..in，forEach，for..of也无法获得期望的结果

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);

对于文档http://react-dnd.github.io，仅发现以下内容：将元素作为可拖动节点。为此，请在呈现函数中用element替换任何this.props.connectDragSource(element)。

Answer 1

您可能想要创建一个单独的组件来渲染每个项目并将其作为拖动源。您还需要从规范中的canDrag函数返回true。

免责声明：我尚未测试以下代码。

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);

映射中每个元素的connectDragSource（拖放：React DnD）

1 个答案: