小编Der*_*xie的帖子

我在node.js文件系统中遇到了问题.这是我的代码.我的函数总是返回一个空字符串.我想知道是否有任何方法使我的函数停止执行,直到readFile方法完成.

var fs = require('fs');
function myfun(filePath){
  var str = '';
  fs.readFile(filePath, function(err, data){
    if(err) throw err;
    str = data;
  });
  return str; //here, the variable str always return '' because the function doesn't wait for the readFile method complete.
}

添加说明

实际上我正在做这样的事情:函数myfun用于替换str你可以看到我的代码:

function fillContent(content) {
  var rex = /\<include.*?filename\s*=\s*"(.+?)"\/>/g;
  var replaced = fileStr.replace(rex, function (match, p1) {
    var filePath = p1
    var fileContent = '';
    fs.readFile(filePath, function (err, data) {
      if (err) {
        throw err;
      }
      fileContent = data; …

我想要一个带有如下图像序列的基于滚动的动画：

http://www.clearmotion.com/technology

这个动画看起来很流畅

我试过这个小提琴

var images = new Array();
var currentLocation = 0;
var totalImages = 200;

for (var i = 1; i < totalImages; i++) {
    var img = new Image;
   
    var slug = '000' + i;
    
     img.src = 'https://s3.amazonaws.com/clearmotion/hero/high-min/frame'+ slug.slice(-3) +'-low.jpg'
    images.push(img);
}

var c = document.getElementById("background");
var ctx = c.getContext("2d");

var mouseWheel = function () {
    window.addEventListener('mousewheel', function (e) {
        e.preventDefault(); // No scroll

        // The following equation will return either a 1 for scroll down
        // …