小编Mr *_* Br的帖子

monitor.getDropResult()返回null(我看它是console.log).它应该返回对象(拖动项)及其位置.为什么它返回null？

我使用DragSource,DropTarget对我的组件进行签名.但它仍然返回null

这是我的整个组件代码:

import React, { PropTypes } from 'react';
import { DragSource } from 'react-dnd';
import { getEmptyImage } from 'react-dnd-html5-backend';

import { StoneConstants, StoneTypes, ItemTypes } from 'constants/AppConstants';
import OkeyStoneBase from 'components/OkeyStoneBase/OkeyStoneBase';

import './_OkeyStone.scss';

function checkForDragAction(props) {

  // TODO receive the action via prop
  if (props.stoneType === StoneTypes.ON_WITHDRAW_MIDDLE) {
    props.onWithdrawMiddle();
  } else if (props.stoneType === StoneTypes.ON_DISCARD_WEST) {
    props.onWithdrawLeft();
  }
}

function applyDropResult(props, result) {

  if (props.stoneType === StoneTypes.ON_WITHDRAW_MIDDLE || props.stoneType === StoneTypes.ON_DISCARD_WEST) {
      if (result === null) …

我想使用自定义流来处理child_process.spawn stdio.

例如

const cp = require('child_process');
const process = require('process');
const stream = require('stream');

var customStream = new stream.Stream();
customStream.on('data', function (chunk) {
    console.log(chunk);
});

cp.spawn('ls', [], {
    stdio: [null, customStream, process.stderr]
});

我收到错误Incorrect value for stdio stream.

有child_process.spawn https://nodejs.org/api/child_process.html#child_process_options_stdio的文档.它说stdio选项可以使用Stream对象

流对象 - 使用子进程共享引用tty,文件,套接字或管道的可读或可写流.

我想我错过了这个"指的"部分.