使用SVG基本操作API的实例讲解

var SVG_NS = "http://www.w3.org/2000/svg";var XLINK_NS = http://www.w3.org/1999/xlink;

document.createElementNS(SVG_NS,tagName);

element.appendChild(childElement)

element.setAttribute(name,value);element.getAttribute(name);

element.setAttributeNS(XLINK_NS,'xlink:href',value);

function createTag(tag,objAttr){ var oTag = document.createElementNS('http://www.w3.org/2000/svg',tag);  for(var attr in objAttr){  if(attr == 'xlink:href'){   oTag.setAttributeNS("http://www.w3.org/1999/xlink",attr,objAttr[attr]);  }else{   oTag.setAttribute(attr,objAttr[attr]);  }    }  return oTag;}

<script>function createTag(tag,objAttr){ var oTag = document.createElementNS('http://www.w3.org/2000/svg',tag);  for(var attr in objAttr){  if(attr == 'xlink:href'){   oTag.setAttributeNS("http://www.w3.org/1999/xlink",attr,objAttr[attr]);  }else{   oTag.setAttribute(attr,objAttr[attr]);  }    }  return oTag;} var oSvg = createTag('svg',{'version':'1.1','xmls':'http://www.w3.org/2000/svg',height:'70'});var oCircle = createTag('circle',{'cx':'25','cy':'25','r':20,'fill':'pink'});oSvg.appendChild(oCircle);document.body.appendChild(oSvg);</script>

<style>#box{ height: 300px; width: 300px; background: hsl(20,40%,90%); background-image:linear-gradient(90deg,#fb3 11px,transparent 0), linear-gradient(90deg,#ab4 23px,transparent 0), linear-gradient(90deg,#655 41px,transparent 0); background-size: 41px 100%,61px 100%,83px 100%; } </style><div id="box"></div><script>var oSvg = createTag('svg',{'version':'1.1','xmls':'http://www.w3.org/2000/svg',height:'100%',width:'100%'});var oBox = document.getElementById('box');var W = parseInt(getComputedStyle(oBox).width);var H = parseInt(getComputedStyle(oBox).height);var appearance = { 'dis':H/3, 'r0':H/8,'r':H/10, 'x0':W/2,'y0':H/2, 'fontSize':H/20, 'bg0':'hsla(0,0%,100%,.6)','bg':'hsla(0,0%,100%,.3)', 'color0':'hsl(210,13%,30%)','color':'hsl(210,13%,30%)', 'borderColor0':'rgba(0,0,0,0.3)','bordercolor':'rgba(0,0,0,0.3)', 'strokWidth0':3,'strokWidth':2, 'lineColor':'rgba(0,0,0,0.3)','lineWidth':1,'lineDashed':'5,5'}var data = { text:'前端开发', children:[  {text:'HTML',url:'http://www.cnblogs.com/xiaohuochai/p/5203223.html'},  {text:'CSS',url:'http://www.cnblogs.com/xiaohuochai/p/5249139.html'},  {text:'JS',url:'http://www.cnblogs.com/xiaohuochai/p/5613593.html'},  {text:'ES6',url:'http://www.cnblogs.com/xiaohuochai/p/7233392.html'},  {text:'HTTP',url:'http://www.cnblogs.com/xiaohuochai/p/6392010.html'},  {text:'NodeJS',url:'http://www.cnblogs.com/xiaohuochai/p/6940560.html'},  {text:'前端工具',url:'http://www.cnblogs.com/xiaohuochai/p/6666415.html'}, ], }addChildenTags();addCenterTag();oBox.appendChild(oSvg);function createTag(tag,objAttr){ var oTag = document.createElementNS('http://www.w3.org/2000/svg',tag);  for(var attr in objAttr){  if(attr == 'xlink:href'){   oTag.setAttributeNS("http://www.w3.org/1999/xlink",attr,objAttr[attr]);  }else{   oTag.setAttribute(attr,objAttr[attr]);  }    }  return oTag;} function addCenterTag(){ var oG = createTag('g',{'style':'cursor:default'}); var oCircle = createTag('circle',{'cx':appearance.x0,'cy':appearance.y0,'r':appearance.r0,'fill':appearance.bg0,'stroke':appearance.borderColor0,'stroke-width':appearance.strokWidth0}); var oText = createTag('text',{'x':appearance.x0,'y':appearance.y0,'font-size':appearance.fontSize,'text-anchor':'middle','dominant-baseline':'middle','stroke-width':appearance.strokWidth0}); oText.innerHTML = data.text; oG.appendChild(oCircle); oG.appendChild(oText); oSvg.appendChild(oG);}function addChildenTags(){ var children = data.children; var length = children.length; var deg = (360/length)*(2*Math.PI)/360; for(var i = 0; i < children.length;i++){  var cos = Math.cos(deg*i - 90);  var sin = Math.sin(deg*i - 90);  var x = appearance.x0 + appearance.dis*cos;  var y = appearance.y0 + appearance.dis*sin;  var oA = createTag('a',{'xlink:href':children[i].url,'target':'_black'});   var oG = createTag('g',{'style':'cursor:pointer'});   oG.index = i;      var oLine = createTag('line',{'x1':x-appearance.r*cos,y1:y-appearance.r*sin,x2:appearance.x0+appearance.r0*cos,y2:appearance.y0+appearance.r0*sin,'stroke':appearance.lineColor,'stroke-width':appearance.lineWidth,'stroke-dasharray':appearance.lineDashed,'style':'transition:.5s'});  var oLineHelper = createTag('line',{'x1':x-appearance.r*cos,y1:y-appearance.r*sin,x2:appearance.x0+appearance.r0*cos,y2:appearance.y0+appearance.r0*sin,'stroke':'transparent','stroke-width':10});    var oCircle = createTag('circle',{'cx':x,'cy':y,'r':appearance.r,'fill':appearance.bg,'stroke':appearance.bordercolor,'stroke-width':appearance.strokWidth,'class':'frostedglass'});  var oText = createTag('text',{'x':x,'y':y,'font-size':appearance.fontSize,'text-anchor':'middle','dominant-baseline':'middle','stroke-width':appearance.strokWidth,fill:appearance.color});  oText.innerHTML = children[i].text;   oG.appendChild(oLine);  oG.appendChild(oLineHelper);     oG.appendChild(oCircle);       oG.appendChild(oText);  oA.appendChild(oG);  oSvg.appendChild(oA);  oG.onmouseenter = function(){   elasticMove(this,appearance.r*1.2);   var line = this.children[0];   line.removeAttribute('stroke-dasharray');   line.setAttribute('stroke-width',appearance.lineWidth*3);   line.setAttribute('x1',appearance.x0+(appearance.dis - appearance.r0)*Math.cos(deg*this.index - 90));   line.setAttribute('y1',appearance.y0+(appearance.dis - appearance.r0)*Math.sin(deg*this.index - 90));  }  oG.onmouseleave = function(){   elasticMove(this,appearance.r);   var line = this.children[0];   line.setAttribute('stroke-width',appearance.lineWidth);   line.setAttribute('stroke-dasharray',appearance.lineDashed);   line.setAttribute('x1',appearance.x0+(appearance.dis - appearance.r)*Math.cos(deg*this.index - 90));   line.setAttribute('y1',appearance.y0+(appearance.dis - appearance.r)*Math.sin(deg*this.index - 90));     }    }}function elasticMove(obj,str){ var circle = obj.getElementsByTagName('circle')[0]; var r0 = circle.getAttribute('r'); var r = Number(str); //声明步长值 var step = 0; //声明弹性距离 var len = r - r0; //声明弹性系数 var k = 0.7; //声明损耗系数 var z= 0.7; //声明当前值 var cur = r0; clearInterval(circle.timer); circle.timer = setInterval(function(){  //获取当前值cur  cur = circle.getAttribute('r');  //更新弹性距离  len = r - cur;  //弹力影响  step += len*k;  //阻力影响  step = step*z;  //赋值  circle.setAttribute('r',Number(cur) + step);  //当元素的步长值接近于0，并且弹性距离接近于0时，停止定时器  if(Math.round(step) == 0 && Math.round(len) == 0){   circle.setAttribute('r',r);   clearInterval(circle.timer);   }  },30);}</script>