Question

我想阅读带有数字的文本文件，并将它们放入带有XMHLHttpRequest的矩阵

我已经使用了FileReader API，但出于某种原因，当我使用它时，我的应用程序出现了一些图形错误。

我的想法是获取文本文件中的数字并与Babylon.js一起使用，这样我就可以在画布上绘制点。

文件示例：

ng build

Complete example

我想跳过所有这些第一行并开始阅读 [ARESTAS] 关键字或 TAM 关键字并将数字放入矩阵[n] [9]，其中n是关键字

之后的行数

前六个数字表示画布中的坐标（x，y，z），后三个表示对象颜色

这就是我对FileReader所做的：

NUM_GRUPOS 1
[GRUPO]
TAM 64
[PONTOS]
ROTULO 1
 2.50000000000000E+0002 -2.00000000000000E+0002  2.00000000000000E+0001  0.00000000000000E+0000  0.00000000000000E+0000  1.00000000000000E+0000  0.00000000000000E+0000  0.00000000000000E+0000  0.00000000000000E+0000  0.00000000000000E+0000
ROTULO 2
 3.54000000000000E+0002 -2.52000000000000E+0002  3.90000000000000E+0002  1.00000000000000E+0000  0.00000000000000E+0000  0.00000000000000E+0000  0.00000000000000E+0000  0.00000000000000E+0000  0.00000000000000E+0000  0.00000000000000E+0000
... //A bunch of other numbers
[ARESTAS]
TAM 60
 2.50000000000000E+0002-2.00000000000000E+0002 2.00000000000000E+0001 3.09941176470588E+0002-1.59941176470588E+0002 8.58823529411765E+0001 0.00000000000000E+0000 0.00000000000000E+0000 1.00000000000000E+0000

Answer 1

为什么要迭代行？

        r.onload = function(e) {
            contents = e.target.result;
            var pos = contents.indexOf(keyWord) + keyWord.length; //find [ARESTAS] portion
            var numbers = contents.substr(pos).trim(); //trim it from rest of file
            matrix = numbers.split('\n') // get separate lines
                .map(function (e) {
                    return e.split(' '); // split them by whitespace
                })
                .filter(function (e) {
                    return e.length > 2; // filter all unwanted lines
                })
        }

......甚至：

    function readMatrix(url, callback) {
        var xhr = new XMLHttpRequest();
        xhr.open("GET", url);
        xhr.onload = function(e) {
            var contents = e.target.result;
            var pos = contents.indexOf(keyWord) + keyWord.length; //find [ARESTAS] portion

            var matrix = contents
                .substr(pos) // get arestas section
                .trim(); //trim redundant whitespace
                .split('\n') // get separate lines
                .slice(1) // skip TAM ### line
                .map(function (e) {
                    return e.split(' '); // split separate lines by whitespace
                }); // get final matrix

            callback(matrix); // pass received data to callback
        }
        xhr.send();
    }

    document.getElementById('fileinput')
        .addEventListener('change', function () {

            var url = ... address of file

            ...

            readMatrix(function (matrix) {

               // we got filled matrix here

            });
        }, false);

Answer 2

可以尝试这个作为起点

    var start = contents.indexOf('[ARESTAS]');
    // get rid of all before ARESTAS, then split and remove first 2 rows
    var txtArr = txt.slice(start).split('\r\n').splice(2);
    //trim and  split each line at space and map to array of numbers
    var numArr = txtArr.reduce(function(a, c){
      a.push(c.trim().split(' ').map(Number))
      return a
    },[])

的 DEMO

XMLHttpRequest：将文本文件读入矩阵

2 个答案: