Question

我使用Mike's code来创建条形图，但似乎无法在其上获得渐变。页面呈现为空白。 Firebug没有显示错误，所以我基本上有两个问题：
1.我做错了什么？ 2.当样式中存在错误且Firebug未显示错误时，如何调试并找出导致问题的原因？

代码：

<!DOCTYPE html>
<html>
<body>
<meta charset="utf-8">
<style>

.chart rect {
  fill: steelblue;
}

.chart text {
  fill: white;
  font: 10px sans-serif;
  text-anchor: end;
}

</style>
<svg class="chart"></svg>
<script src="d3/d3.v3.min.js"></script>
<script>
var svg = d3.select("body");

var gradient = svg.append("svg:defs")
    .append("svg:linearGradient")
    .attr("id", "gradient")
    .attr("x1", "0%")
    .attr("y1", "0%")
    .attr("x2", "100%")
    .attr("y2", "100%")
    ;//.attr("spreadMethod", "pad");

gradient.append("svg:stop")
    .attr("offset", "0%")
    .attr("stop-color", "#0c0")
    .attr("stop-opacity", 1);

gradient.append("svg:stop")
    .attr("offset", "100%")
    .attr("stop-color", "#c00")
    .attr("stop-opacity", 1);


var data = [4, 8, 15, 16, 23, 42];
var width = 420, barHeight = 20;

var svg = d3.select("body").append("svg:svg")
    .attr("width", width)
    .attr("height", barHeight);

    var gradient = svg.append("svg:defs")
    .append("svg:linearGradient")
    .attr("id", "gradient")
    .attr("x1", "0%")
    .attr("y1", "0%")
    .attr("x2", "100%")
    .attr("y2", "100%")
    .attr("spreadMethod", "pad");

    gradient.append("svg:stop")
    .attr("offset", "0%")
    .attr("stop-color", "#0c0")
    .attr("stop-opacity", 1);

    gradient.append("svg:stop")
    .attr("offset", "100%")
    .attr("stop-color", "#c00")
    .attr("stop-opacity", 1);

var x = d3.scale.linear()
    .domain([0, d3.max(data)])
    .range([0, width]);

var chart = d3.select(".chart")
    .attr("width", width)
    .attr("height", barHeight * data.length);

var bar = chart.selectAll("g")
    .data(data)
    .enter().append("g")
    .attr("transform", function(d, i) { return "translate(0," + i * barHeight + ")"; });

bar.append("rect")
    .attr("width", x)
    .attr("height", barHeight - 1)
    .style("fill", "url(#gradient)");


bar.append("text")
    .attr("x", function(d) { return x(d) - 3; })
    .attr("y", barHeight / 2)
    .attr("dy", ".35em")
    .text(function(d) { return d; });

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

Answer 1

您的示例中有两个具有相同ID的渐变。您还没有为html或body元素指定宽度，这意味着您将看不到任何内容。否则你的代码是正确的。

这适用于Firefox ...

<!DOCTYPE html>
<html>
<body>
<meta charset="utf-8">
<style>

.chart rect {
  fill: steelblue;
}

.chart text {
  fill: white;
  font: 10px sans-serif;
  text-anchor: end;
}

html, body {
  width: 100%;
  height: 100%;
}

</style>
<svg class="chart"></svg>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>
var svg = d3.select("body");


var data = [4, 8, 15, 16, 23, 42];
var width = 420, barHeight = 20;

var svg = d3.select("body").append("svg:svg")
    .attr("width", width)
    .attr("height", barHeight);

    var gradient = svg.append("svg:defs")
    .append("svg:linearGradient")
    .attr("id", "gradient")
    .attr("x1", "0%")
    .attr("y1", "0%")
    .attr("x2", "100%")
    .attr("y2", "100%")
    .attr("spreadMethod", "pad");

    gradient.append("svg:stop")
    .attr("offset", "0%")
    .attr("stop-color", "#0c0")
    .attr("stop-opacity", 1);

    gradient.append("svg:stop")
    .attr("offset", "100%")
    .attr("stop-color", "#c00")
    .attr("stop-opacity", 1);

var x = d3.scale.linear()
    .domain([0, d3.max(data)])
    .range([0, width]);

var chart = d3.select(".chart")
    .attr("width", width)
    .attr("height", barHeight * data.length);

var bar = chart.selectAll("g")
    .data(data)
    .enter().append("g")
    .attr("transform", function(d, i) { return "translate(0," + i * barHeight + ")"; });

bar.append("rect")
    .attr("width", x)
    .attr("height", barHeight - 1)
    .style("fill", "url(#gradient)");


bar.append("text")
    .attr("x", function(d) { return x(d) - 3; })
    .attr("y", barHeight / 2)
    .attr("dy", ".35em")
    .text(function(d) { return d; });

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

d3.js：在条形图上获得渐变？

1 个答案: