Question

所以我需要使用本地加载的HTML网页（例如file：///）读取.CSV文件，并使用d3.js在图表上绘制内容。到目前为止，我试图将两个例子加在一起但没有成功......

如果打开它，它可以读取本地csv文件的内容，但由于某种原因，图形不会出现。

非常感谢任何帮助！

<!DOCTYPE html>
<style> /* set the CSS */

body { font: 12px Arial;}

path { 
    stroke: steelblue;
    stroke-width: 2;
    fill: none;
}

.axis path,
.axis line {
    fill: none;
    stroke: grey;
    stroke-width: 1;
    shape-rendering: crispEdges;
}

</style>

<html lang="en">
  <head>
    <meta http-equiv="X-UA-Compatible" content="chrome=1" />
    <meta http-equiv="Content-Type" content="text/html;charset=utf-8"/>
    <!--this doesn't seem to help-->
    <meta http-equiv="Access-Control-Allow-Origin" content="*"/>
    <title>Process local CSV file</title>
    <script src="d3.js" charset="utf-8"></script>
  </head>
  <body>
    <script>
       var rowToHtml = function( row ) {
         var result = "";
         for (key in row) {
           result += key + ": " + row[key] + "<br/>"
         }
         return result;
       }

       var previewCsvUrl = function( csvUrl ) {
         d3.csv( csvUrl, function( rows ) {
           d3.select("div#preview").html(
             "<b>First row:</b><br/>" + rowToHtml(rows[0]));
         })
       }

       d3.select("html")
          .style("height","100%")

       d3.select("body")
          .style("height","100%")
          .style("font", "12px sans-serif")

        .append("input")
          .attr("type", "file")
          .attr("accept", ".csv")
          .style("margin", "5px")
          .on("change", function() {
            var file = d3.event.target.files[0];
            if (file) {
              var reader = new FileReader();
                reader.onloadend = function(event1) {
                  var dataUrl = event1.target.result;
                  // The following call results in an "Access denied" error in IE.
                  previewCsvUrl(dataUrl);
                  rendergraph(dataUrl);
              };
             reader.readAsDataURL(file);
            }
         })

      d3.select("body")
       .append("div")
         .attr("id", "preview")
         .style("margin", "5px")


var svg = d3.select("svg"),
    margin = {top: 20, right: 20, bottom: 30, left: 50},
    width = +svg.attr("width") - margin.left - margin.right,
    height = +svg.attr("height") - margin.top - margin.bottom,
    g = svg.append("g").attr("transform", "translate(" + margin.left + "," + margin.top + ")");

var parseTime = d3.timeParse("%d-%b-%y");

var x = d3.scaleTime()
    .rangeRound([0, width]);

var y = d3.scaleLinear()
    .rangeRound([height, 0]);

var line = d3.line()
    .x(function(d) { return x(d.date); })
    .y(function(d) { return y(d.close); });

var rendergraph = function( url1 ) {
d3.csv(url1, function(d) {
  d.date = parseTime(d.date);
  d.close = +d.close;
  return d;
}, function(error, data) {
  if (error) throw error;

  x.domain(d3.extent(data, function(d) { return d.date; }));
  y.domain(d3.extent(data, function(d) { return d.close; }));

  g.append("g")
      .attr("transform", "translate(0," + height + ")")
      .call(d3.axisBottom(x))
    .select(".domain")
      .remove();

  g.append("g")
      .call(d3.axisLeft(y))
    .append("text")
      .attr("fill", "#000")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", "0.71em")
      .attr("text-anchor", "end")
      .text("Price ($)");

  g.append("path")
      .datum(data)
      .attr("fill", "none")
      .attr("stroke", "steelblue")
      .attr("stroke-linejoin", "round")
      .attr("stroke-linecap", "round")
      .attr("stroke-width", 1.5)
      .attr("d", line);
});

}

    </script>
  </body>
</html>

Answer 1

svg正在这里被选中，但它不在dom中：

show b

在html中添加svg元素或使用d3追加到body，方法是将上面的代码替换为：

var svg = d3.select("svg"),

Javascript d3.js读取本地CSV文件

1 个答案: