【发布时间】：2015-02-13 09:10:09
【问题描述】：
我见过this question 和many other 的例子，但它没有帮助。我正在尝试this page 上的最后一个示例，5 秒后，我希望正在绘制的弯曲路径完全消失，再过 5 秒，我希望创建一条新路径。
我已经尝试了下面的代码，但是虽然整个 svg 元素本身已被删除，但当我使用 appendGraph() 再次创建 svg 和路径时，相同的旧路径重新出现。如何确保完全删除旧路径并且在删除图形时也不会调用刻度函数？
小提琴在这里：http://jsfiddle.net/nav9/5uygqj9v/
代码是：
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<style>
svg {
font: 10px sans-serif;
}
.noselect {
/* these are to disable text selection */
-webkit-touch-callout: none;
-webkit-user-select: none;
-khtml-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
}
.axis path,
.axis line {
fill: none;
stroke: #000;
opacity: 0.5;
shape-rendering: crispEdges;
}
rect.zoom {
stroke: steelblue;
fill-opacity: 0.3;
}
#placeholder {margin: 10px 5px 15px 70px;}
</style>
<script type="text/javascript" src="http://d3js.org/d3.v3.js"></script>
</head>
<body>
<div id="placeholder" ></div>
<script>
//---------globals
var timer = null, interval = 500, value = 0;
var value1 = 0;
var n = 143, duration = interval, now = new Date(Date.now() - duration), count = 0, data = d3.range(n).map(function() { return 0; });
var margin = {top: 20, right: 40, bottom: 50, left: 60}, width = 580 - margin.right, height = 420 - margin.top - margin.bottom;
var x = d3.time.scale().domain([now - (n - 2) * duration, now - duration]).range([0, width]);
var y = d3.scale.linear().domain([-1, 1]).range([height, 0]);
var line = d3.svg.line().interpolate("basis")
.x(function(d, i) { return x(now - (n - 1 - i) * duration); })
.y(function(d, i) { return y(d); });
var svg, path, yaxis, axis;
//--------program starts
appendGraph();
tick();
value1 = 0;
setTimeout(function() {removeGraph();}, 5000);
setTimeout(function() {addGraphAgain();}, 10000);
//-------------------------------functions -------------------------------
function appendGraph()
{
svg = d3.select("body").select("#placeholder").append("p").append("svg:svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.attr("id", "mainSVG")
.style("margin-left", -margin.left + "px")
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
svg.append("defs").append("clipPath")
.attr("id", "clip")
.append("rect")
.attr("width", width)
.attr("height", height);
axis = svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(x.axis = d3.svg.axis().scale(x).orient("bottom"));
yaxis = svg.append("g")
.attr("class", "y axis")
.call(y.axis = d3.svg.axis().scale(y).orient("left"));
path = svg.append("g")
.attr("clip-path", "url(#clip)")
.append("path")
.data([data])
.attr("id", "line1")
.attr("fill", "none")
.attr("stroke", "black")
.attr("stroke-width", "1.5px")
.style("visibility","visible");
}//appendGraph
//TODO: These tick functions could be simplified to handle more lines on the graph
function tick()
{
// push the accumulated count onto the back, and reset the count
value1 = Math.random() * 100;
if (value1 >= 0) {data.push(value1);} else {data.push(0);}//ensure that no NaN or undefined values corrupt the range
// update the domains
now = new Date();
x.domain([now - (n - 2) * duration, now - duration]);
count = 0;
// redraw the lines
svg.select("#line1").attr("d", line).attr("transform", null);
// slide the line left
path.transition().duration(duration).ease("linear").attr("transform", "translate(" + x(now - (n - 1) * duration) + ")").each("end", tick);
y.domain([0, 100]);
y = d3.scale.linear().domain([0, 100]).range([height, 0]);
yaxis.call(y.axis = d3.svg.axis().scale(y).orient("left"));
// pop the old data point off the front
data.shift();
console.log("tick being called");
}
function removeGraph()
{
path.transition().duration(0).each(function() { this.__transition__.active = 0; });//at least this is stopping tick from being called
svg.selectAll("*").remove();
//-------tried these too
// d3.select("#mainSVG").remove("svg");
// d3.select("#line1").remove("path");
// path.remove();
//d3.selectAll("path").attr("d", "Z");
console.log("REMOVED");
}//removeGraph
function addGraphAgain()
{
appendGraph();
tick();
value1 = 0;
console.log("ADDED AGAIN");
}//addGraphAgain
</script>
</body>
</html>
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