前言
了解了D3.js的基本开发和组件以后，我们开始应用它激动人心之处：绚丽的预定义图形，应用D3.js，我们在它的示例文件的基础上稍加变动即可应用于我们的数据可视化工作中，D3.js将后台的运算已经预定义好，我们只需少量代码和规范的数据，就能做出很花哨（请原谅我的用词不当）的效果。
力学图（也称为导向图，也有叫网络拓补图的，反正就是通过排斥得到关系远近的结构）在社交网络研究、信息传播途径等群体关系研究中应用非常广泛，它可以直观地反映群体与群体之间联系的渠道、交集多少，群体内部成员的联系强度等。
本文实现如下面的效果(用非IE浏览器可以看到效果)：
代码有点长，但是也不复杂，可以参考如下代码：
<!DOCTYPE html><html><head><script type="text/javascript" src="http://mbostock.github.com/d3/d3.v2.js?2.9.1"></script><style type="text/css">.link { stroke: green; stroke-linejoin:bevel;}.link_error{ stroke:red; stroke-linejoin:bevel;}.nodetext { font: 12px sans-serif; -webkit-user-select:none; -moze-user-select:none; stroke-linejoin:bevel; }#container{ width:800px; height:600px; border:1px solid gray; border-radius:5px; position:relative; margin:20px;}</style></head><body> <div id='container'></div><script type="text/javascript">function Topology(ele){ typeof(ele)=='string' && (ele=document.getElementById(ele)); var w=ele.clientWidth, h=ele.clientHeight, self=this; this.force = d3.layout.force().gravity(.05).distance(200).charge(-800).size([w, h]); this.nodes=this.force.nodes(); this.links=this.force.links(); this.clickFn=function(){}; this.vis = d3.select(ele).append("svg:svg") .attr("width", w).attr("height", h).attr("pointer-events", "all"); this.force.on("tick", function(x) { self.vis.selectAll("g.node") .attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; }); self.vis.selectAll("line.link") .attr("x1", function(d) { return d.source.x; }) .attr("y1", function(d) { return d.source.y; }) .attr("x2", function(d) { return d.target.x; }) .attr("y2", function(d) { return d.target.y; }); });}Topology.prototype.doZoom=function(){ d3.select(this).select('g').attr("transform","translate(" + d3.event.translate + ")"+ " scale(" + d3.event.scale + ")");}//增加节点Topology.prototype.addNode=function(node){ this.nodes.push(node);}Topology.prototype.addNodes=function(nodes){ if (Object.prototype.toString.call(nodes)=='[object Array]' ){ var self=this; nodes.forEach(function(node){ self.addNode(node); }); }}//增加连线Topology.prototype.addLink=function(source,target){ this.links.push({source:this.findNode(source),target:this.findNode(target)});}//增加多个连线Topology.prototype.addLinks=function(links){ if (Object.prototype.toString.call(links)=='[object Array]' ){ var self=this; links.forEach(function(link){ self.addLink(link['source'],link['target']); }); }}//删除节点Topology.prototype.removeNode=function(id){ var i=0, n=this.findNode(id), links=this.links; while ( i < links.length){ links[i]['source']==n || links[i]['target'] ==n ? links.splice(i,1) : ++i; } this.nodes.splice(this.findNodeIndex(id),1);}//删除节点下的子节点，同时清除link信息Topology.prototype.removeChildNodes=function(id){ var node=this.findNode(id), nodes=this.nodes; links=this.links, self=this; var linksToDelete=[], childNodes=[]; links.forEach(function(link,index){ link['source']==node && linksToDelete.push(index) && childNodes.push(link['target']); }); linksToDelete.reverse().forEach(function(index){ links.splice(index,1); }); var remove=function(node){ var length=links.length; for(var i=length-1;i>=0;i--){ if (links[i]['source'] == node ){ var target=links[i]['target']; links.splice(i,1); nodes.splice(self.findNodeIndex(node.id),1); remove(target); } } } childNodes.forEach(function(node){ remove(node); }); //清除没有连线的节点 for(var i=nodes.length-1;i>=0;i--){ var haveFoundNode=false; for(var j=0,l=links.length;j<l;j++){ ( links[j]['source']==nodes[i] || links[j]['target']==nodes[i] ) && (haveFoundNode=true) } !haveFoundNode && nodes.splice(i,1); }}//查找节点Topology.prototype.findNode=function(id){ var nodes=this.nodes; for (var i in nodes){ if (nodes[i]['id']==id ) return nodes[i]; } return null;}//查找节点所在索引号Topology.prototype.findNodeIndex=function(id){ var nodes=this.nodes; for (var i in nodes){ if (nodes[i]['id']==id ) return i; } return -1;}//节点点击事件Topology.prototype.setNodeClickFn=function(callback){ this.clickFn=callback;}//更新拓扑图状态信息Topology.prototype.update=function(){ var link = this.vis.selectAll("line.link") .data(this.links, function(d) { return d.source.id + "-" + d.target.id; }) .attr("class", function(d){ return d['source']['status'] && d['target']['status'] ? 'link' :'link link_error'; }); link.enter().insert("svg:line", "g.node") .attr("class", function(d){ return d['source']['status'] && d['target']['status'] ? 'link' :'link link_error'; }); link.exit().remove(); var node = this.vis.selectAll("g.node") .data(this.nodes, function(d) { return d.id;}); var nodeEnter = node.enter().append("svg:g") .attr("class", "node") .call(this.force.drag); //增加图片，可以根据需要来修改 var self=this; nodeEnter.append("svg:image") .attr("class", "circle") .attr("xlink:href", function(d){ //根据类型来使用图片 return d.expand ? "http://ww2.sinaimg.cn/large/412e82dbjw1dsbny7igx2j.jpg" : "http://ww4.sinaimg.cn/large/412e82dbjw1dsbnxezrrpj.jpg"; }) .attr("x", "-32px") .attr("y", "-32px") .attr("width", "64px") .attr("height", "64px") .on('click',function(d){ d.expand && self.clickFn(d);}) nodeEnter.append("svg:text") .attr("class", "nodetext") .attr("dx", 15) .attr("dy", -35) .text(function(d) { return d.id }); node.exit().remove(); this.force.start();}var topology=new Topology('container');var nodes=[ {id:'10.4.42.1',type:'router',status:1}, {id:'10.4.43.1',type:'switch',status:1,expand:true}, {id:'10.4.44.1',type:'switch',status:1}, {id:'10.4.45.1',type:'switch',status:0}];var childNodes=[ {id:'10.4.43.2',type:'switch',status:1}, {id:'10.4.43.3',type:'switch',status:1}];var links=[ {source:'10.4.42.1',target:'10.4.43.1'}, {source:'10.4.42.1',target:'10.4.44.1'}, {source:'10.4.42.1',target:'10.4.45.1'}];var childLinks=[ {source:'10.4.43.1',target:'10.4.43.2'}, {source:'10.4.43.1',target:'10.4.43.3'}, {source:'10.4.43.2',target:'10.4.43.3'}]topology.addNodes(nodes);topology.addLinks(links);//可展开节点的点击事件topology.setNodeClickFn(function(node){ if(!node['_expanded']){ expandNode(node.id); node['_expanded']=true; }else{ collapseNode(node.id); node['_expanded']=false; }});topology.update();function expandNode(id){ topology.addNodes(childNodes); topology.addLinks(childLinks); topology.update();}function collapseNode(id){ topology.removeChildNodes(id); topology.update();}</script></body></html>总结
以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作能带来一定的帮助，如果有疑问大家可以了留言交流。
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