最近有个需求, 需要实现一下拖拽排序, 不需要动画, 能实现功能即可. 现有的类库就不太想集成, 自己手撸一下, 实现即可.

1. 首先设置state

constructor(props) {
    super(props);
    this.state = {
      dataArray: [],
      dragElement: null,
      lock: true,
    };
  }

这个dataArray就是我们的数据源

2. 在componentDidMount中阻止一下dragover和drop的默认行为

componentDidMount() {
    document.addEventListener('dragover', this.preventDefault);
    document.addEventListener('drop', this.preventDefault);
  }

这里的this.preventDefault方法是我自己封装了一下的

preventDefault = (e) => {
   e.preventDefault();
 }

3. 在componentWillUnmount中删除监听器

componentWillUnmount() {
    document.removeEventListener('dragover', this.preventDefault);
    document.removeEventListener('drop', this.preventDefault);
  }

4. 给要排序的元素实现如下属性

sortableCard = (sortableInfo) => {
    const { id } = sortableInfo;
    }
    return (
      <div
        key={id}
        draggable
        onDragStart={() => {
          this.setState({
            dragElement: sortableInfo,
          });
        }}
        onDragEnd={(e) => {
          e.preventDefault();
        }}
        onDragEnter={() => {
          if (id !== this.state.dragElement.id) {
            const oldDragIndex = _.findIndex(this.state.dataArray, item => item.id === this.state.dragElement.id);
            const oldEnterIndex = _.findIndex(this.state.dataArray, item => item.id === sortableInfo.id);
            if (oldDragIndex > oldEnterIndex) {
              const newDataArray= this.state.dataArray.filter(item => item.id !== this.state.dragElement.id);
              const insertIndex = _.findIndex(newDataArray, item => item.id === sortableInfo.id);
              newDataArray.splice(insertIndex, 0, this.state.dragElement);
              this.setState({ dataArray: newDataArray });
            } else {
              const newDataArray = this.state.dataArray.filter(item => item.id !== this.state.dragElement.id);
              const insertIndex = _.findIndex(newDataArray, item => item.Id === sortableInfo.id) + 1;
              newDataArray.splice(insertIndex, 0, this.state.dragElement);
              this.setState({ dataArray: newDataArray });
            }
            this.setState({
              isConfigDirty: true,
            });
          }
        }}
        onDragLeave={() => {
          if (sortableInfo.id !== this.state.dragElement.id) {
            if (this.state.lock && sortableInfo.id === this.state.dataArray[this.state.dataArray.length - 1]) {
              const newDataArray = this.state.dataArray.filter(item => item.id !== this.state.dragElement.id);
              newDataArray.push(this.state.dragElement);
              this.setState({
                lock: false,
              }, () => {
                this.setState({
                  dataArray: newDataArray,
                });
              });
            } else {
              this.setState({
                lock: true,
              });
            }
          }
        }}
      >
          <div>你的东西</div>
      </div>
    );
  }