动态添加网络拓扑节点、svg下载
程序员文章站
2022-06-07 14:58:54
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一、效果
二、代码
html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>拓扑图</title>
<style>
.link {
}
.node {
cursor: move;
}
.node.fixed {
fill: #000;
}
.dialog {
display: none;
position: absolute;
top: 0;
padding: 1em;
font-size: 14px;
border-radius: 0.5em;
box-shadow: 0 0 20px #ccc;
background: #fff;
z-index: 10;
}
</style>
</head>
<body>
<div><button id="download">下载</button></div>
</body>
</html>js
“d3版本”: “^3.5.17”
import 'd3'
import $ from 'jquery'
let graph = {
"nodes": [
{"x": 469, "y": 410},
{"x": 493, "y": 364},
{"x": 442, "y": 365},
{"x": 467, "y": 314},
{"x": 477, "y": 248},
{"x": 425, "y": 207},
{"x": 402, "y": 155},
{"x": 369, "y": 196},
{"x": 350, "y": 148},
{"x": 539, "y": 222},
{"x": 594, "y": 235},
{"x": 582, "y": 185},
{"x": 633, "y": 200}
],
"links": [
{"source": 0, "target": 1},
{"source": 1, "target": 2},
{"source": 2, "target": 0},
{"source": 1, "target": 3},
{"source": 3, "target": 2},
{"source": 3, "target": 4},
{"source": 4, "target": 5},
{"source": 5, "target": 6},
{"source": 5, "target": 7},
{"source": 6, "target": 7},
{"source": 6, "target": 8},
{"source": 7, "target": 8},
{"source": 9, "target": 4},
{"source": 9, "target": 11},
{"source": 9, "target": 10},
{"source": 10, "target": 11},
{"source": 11, "target": 12},
{"source": 12, "target": 10}
]
};
document.oncontextmenu = function(){
return false;
}
let width = 960,
height = 500,
dialog = Dialog();
let force = d3.layout.force()
.size([width, height])
.nodes(graph.nodes)
.links(graph.links)
.charge(-700)
.linkDistance(40)
.on("tick", tick);
let drag = force.drag()
.on("dragstart", dragstart);
let svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
let link = svg.selectAll(".link"),
node = svg.selectAll(".node");
let nodes = force.nodes(),
links = force.links();
restart(12);
let button = document.getElementById("download");
button.onclick = downLoad;
function tick() {
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; });
node.attr("cx", function(d) { return d.x; })
.attr("cy", function(d) { return d.y; });
}
function dblclick(d) {
//d3.select(this).classed("fixed", d.fixed = false);
}
function dragstart(d) {
//d3.select(this).classed("fixed", d.fixed = true);
}
//单例对话框
function Dialog(){
let dialog = null;
return (function(){
if(dialog == null){
let bodyEle = document.querySelector("body"),
dialogHtml = `<div>
<label>创建节点大小：</label>
<input type="number" value="12" />
</div>
<input name="enter" type="button" value="确定" />
<input name="cancel" type="button" value="取消" />
`;
dialog = document.createElement("div");
dialog.className = "dialog";
dialog.innerHTML = dialogHtml;
bodyEle.appendChild(dialog);
}
return dialog;
})();
}
function mouseRtClick(d,i){
if(d3.event.button){
dialog.style.left = d3.event.x+20+'px';
dialog.style.top = d3.event.y+20+'px';
dialog.style.display = 'block';
dialog.querySelector("input[name='enter']").onclick = function(e){
let node = {x: parseFloat(this.parentNode.style.left)-20, y: parseFloat(this.parentNode.style.top)-20};
nodes.push(node);
// add links to any nearby nodes
links.push({source: node, target: d});
restart(dialog.querySelector("input[type='number']").value);
this.parentNode.style.display = 'none';
};
dialog.querySelector("input[name='cancel']").onclick = function(e){
this.parentNode.style.display = 'none';
};
}
}
function downLoad(){
$("svg")
.attr("version", 1.1)
.attr("xmlns", "http://www.w3.org/2000/svg");
let svg = document.querySelector("svg"),
svgXml = svg.outerHTML,
image = new Image(),
canvas,
context,
a;
//给图片对象写入base64编码的svg流
image.src = 'data:image/svg+xml;base64,' + window.btoa(unescape(encodeURIComponent(svgXml)));
image.onload = function(){
//准备空画布
canvas = document.createElement('canvas');
canvas.width = svg.width.animVal.value;//svg宽度
canvas.height = svg.height.animVal.value;//svg高度
context = canvas.getContext('2d'); //取得画布的2d绘图上下文
//设置图片颜色，避免下载图片为透明的背景
context.fillStyle = "#fff";
context.fillOpacity = "0";
context.fillRect(0,0,canvas.width,canvas.height);
context.drawImage(image, 0, 0);
a = document.createElement('a');
a.href = canvas.toDataURL('image/png'); //将画布内的信息导出为png图片数据
a.download = "网络拓扑.png"; //设定下载名称
a.click(); //点击触发下载
}
}
function restart(r) {
link = link.data(links);
link.enter().insert("line",".node")//使line放到circle前面
.attr("class", "link")
.style("stroke","#000")
.style("stroke-width",'1.5');
node = node.data(nodes);
node.enter().append("circle")
.attr("class", "node")
.attr("r", r)
.style("fill",'#ccc')
.style("stroke","#000")
.style("stroke-width",'1.5')
.on("dblclick", dblclick)
.on("mousedown",mouseRtClick)
.call(drag);
force.start();
}推荐阅读