Javascript 下载d3分层边缘捆绑可视化为PNG时显示的黑色填充链接

Javascript 下载d3分层边缘捆绑可视化为PNG时显示的黑色填充链接,javascript,d3.js,png,Javascript,D3.js,Png,我已经创建了一个D3层次边缘捆绑可视化。当我下载这个可视化为PNG时,下载图像中的链接填充了黑色,而实际可视化中没有显示。 下载的图像是 显示的实际可视化是 如何在下载的图像中获得相同的可视化效果。 我目前的代码是: <html> <head> <style> .node { font: 11px "Helvetica Neue", Helvetica, Arial, sans-s

我已经创建了一个D3层次边缘捆绑可视化。当我下载这个可视化为PNG时,下载图像中的链接填充了黑色,而实际可视化中没有显示。 下载的图像是

显示的实际可视化是

如何在下载的图像中获得相同的可视化效果。 我目前的代码是:

<html>
    <head>

        <style>
            .node {
              font: 11px "Helvetica Neue", Helvetica, Arial, sans-serif;
            }
            .link {
              stroke: steelblue;
              stroke-opacity: .4;
              fill: none;
            }
        </style>

    </head>
    <body>
            <script src="http://d3js.org/d3.v3.min.js"></script>
            <script>
            var classes=[
{"name":"a","size":3938,"imports":["b","f"]},
{"name":"b","size":3938,"imports":[]},
{"name":"c","size":3938,"imports":["a"]},
{"name":"d","size":3938,"imports":[]},
{"name":"e","size":3938,"imports":[]},
{"name":"f","size":3938,"imports":[]}


];
                    var diameter = 700,
                        radius = diameter / 2,
                        innerRadius = radius - 120;
                    var cluster = d3.layout.cluster()
                        .size([360, innerRadius]);

                    var bundle = d3.layout.bundle();

                    var line = d3.svg.line.radial()
                        .interpolate("bundle")
                        .tension(.85)
                        .radius(function(d) { return d.y; })
                        .angle(function(d) { return d.x / 180 * Math.PI; });

                    var svg = d3.select("body").append("svg")
                    .attr("id","networkSvg")
                        .attr("width", diameter)
                        .attr("height", diameter)
                      .append("g")
                        .attr("transform", "translate(" + radius + "," + radius + ")");



                      var nodes = cluster.nodes(packageHierarchy(classes)),
                          links = packageImports(nodes);

                      svg.selectAll(".link")
                          .data(bundle(links))
                        .enter().append("path")
                          .attr("class", "link")
                          .attr("d", line);

                      svg.selectAll(".node")
                          .data(nodes.filter(function(n) { return !n.children; }))
                        .enter().append("g")
                          .attr("class", "node")
                          .attr("transform", function(d) { return "rotate(" + (d.x - 90) + ")translate(" + d.y + ")"; })
                        .on("mouseover", function(d){
                          d3.selectAll(".node").style("fill", "black");
                          d3.selectAll(".link").style("stroke", "steelblue");
                          colorSource(d.name);

                          d.imports.forEach(function(name){
                            colorTarget(name);
                            colorOutgoingLink(d.name, name);
                          });

                          d.parent.children.forEach(function(data){
                              if(data.imports.indexOf(d.name)>-1)
                              {
                                colorTarget(data.name);
                                colorIncomingLink(data.name, d.name);
                              }
                          });
                        })
                        .on("mouseout",function(d)
                        {
                          d3.selectAll(".node").style("fill", "black");
                          d3.selectAll(".link").style("stroke", "steelblue");

                        }) 
                        .append("text")
                          .attr("dx", function(d) { return d.x < 180 ? 8 : -8; })
                          .attr("dy", ".31em")
                          .attr("text-anchor", function(d) { return d.x < 180 ? "start" : "end"; })
                          .attr("transform", function(d) { return d.x < 180 ? null : "rotate(180)"; })
                          .text(function(d) { return d.key; });


                    // Lazily construct the package hierarchy from class names.

                    function packageHierarchy(classes) {
                      var map = {};
                      function find(name, data) {
                        var node = map[name], i;
                        if (!node) {
                          node = map[name] = data || {name: name, children: []};
                          if (name.length) {
                            node.parent = find(name.substring(0, i = name.lastIndexOf(".")));
                            node.parent.children.push(node);
                            node.key = name.substring(i + 1);
                          }
                        }
                        return node;
                      }
                      classes.forEach(function(d) {
                        find(d.name, d);
                      });
                      return map[""];
                    }


                    // Return a list of imports for the given array of nodes.
                    function packageImports(nodes) {
                      var map = {},
                          imports = [];
                      // Compute a map from name to node.
                      nodes.forEach(function(d) {
                        map[d.name] = d;
                      });
                      // For each import, construct a link from the source to target node.
                      nodes.forEach(function(d) {
                        if (d.imports) d.imports.forEach(function(i) {
                          imports.push({source: map[d.name], target: map[i]});
                        });
                      });
                      return imports;
                    }

                    function colorIncomingLink(src,tgt){
                      var link = d3.selectAll(".link")[0].filter(function(d){
                        return (d3.select(d).data()[0][0].name == src && d3.select(d).data()[0][2].name == tgt);
                      });
                      d3.selectAll(link).style("stroke", "green");
                    }

                    function colorOutgoingLink(src,tgt){
                      var link = d3.selectAll(".link")[0].filter(function(d){
                        return (d3.select(d).data()[0][0].name == src && d3.select(d).data()[0][2].name == tgt);
                      });
                      d3.selectAll(link).style("stroke", "red");
                    }

                    function colorTarget(name){
                      //iterate through all teh dom and get the DOM which has the data
                      var node = d3.selectAll(".node")[0].filter(function(d){
                        return d3.select(d).data()[0].name == name;
                      });
                      d3.selectAll(node).style("fill", "red");
                    }

                    function colorSource(name){
                      //iterate through all teh dom and get teh DOM which has the data
                      var node = d3.selectAll(".node")[0].filter(function(d){
                        return d3.select(d).data()[0].name == name;
                      });
                      d3.selectAll(node).style("fill", "green");
                    }

                     function download()
                    {

                        img = new Image(),
                        serializer = new XMLSerializer(),
                        svgStr = serializer.serializeToString(document.getElementById('networkSvg'));

                    img.src = 'data:image/svg+xml;base64,'+window.btoa(svgStr);

                    // You could also use the actual string without base64 encoding it:
                    //img.src = "data:image/svg+xml;utf8," + svgStr;

                    var canvas = document.createElement("canvas");

                    var w=2000;
                    var h=2000;

                    canvas.width = w;
                    canvas.height = h;
                    canvas.getContext("2d").drawImage(img,0,0,w,h);

                    var imgURL = canvas.toDataURL("image/png");


                var dlLink = document.createElement('a');
                    dlLink.download = "down";
                    dlLink.href = imgURL;
                    dlLink.dataset.downloadurl = ["image/png", dlLink.download, dlLink.href].join(':');

                    document.body.appendChild(dlLink);
                    dlLink.click();
                    document.body.removeChild(dlLink);


                    }
                    </script>
                    <button onclick="download()">Download</button>



    </body>
</html>

.节点{
字体:11px“Helvetica Neue”,Helvetica,Arial,无衬线;
}
.链接{
笔画:钢蓝;
笔画不透明度:.4;
填充:无;
}
变量类=[
{“名称”:“a”,“尺寸”:3938,“进口”:[“b”,“f”]},
{“名称”:“b”,“大小”:3938,“导入”:[]},
{“name”:“c”,“size”:3938,“imports”:[“a”]},
{“名称”:“d”,“大小”:3938,“导入”:[]},
{“名称”:“e”,“大小”:3938,“导入”:[]},
{“名称”:“f”,“大小”:3938,“导入”:[]}
];
var直径=700,
半径=直径/2,
内半径=半径-120;
var cluster=d3.layout.cluster()
.尺寸([360,内半径]);
var bundle=d3.layout.bundle();
var line=d3.svg.line.radial()
.插入(“束”)
.张力(.85)
.radius(函数(d){返回d.y;})
.angle(函数(d){返回d.x/180*Math.PI;});
var svg=d3.选择(“正文”).追加(“svg”)
.attr(“id”、“网络SVG”)
.attr(“宽度”,直径)
.attr(“高度”,直径)
.附加(“g”)
.attr(“变换”、“平移”(“+radius+”,“+radius+”));
var nodes=cluster.nodes(packageHierarchy(classes)),
链接=packageImports(节点);
svg.selectAll(“.link”)
.数据(捆绑(链接))
.enter().append(“路径”)
.attr(“类”、“链接”)
.attr(“d”,行);
svg.selectAll(“.node”)
.data(nodes.filter(函数(n){return!n.children;}))
.enter().append(“g”)
.attr(“类”、“节点”)
.attr(“转换”,函数(d){return”旋转(“+(d.x-90)+”)平移(“+d.y+”);})
.on(“鼠标悬停”,功能(d){
d3.选择全部(“.node”)。样式(“填充”、“黑色”);
d3.选择全部(“.link”).样式(“笔划”、“钢蓝”);
色源(d.name);
d、 imports.forEach(函数(名称){
彩色靶标(名称);
着色链接(d.名称、名称);
});
d、 parent.children.forEach(函数(数据){
if(data.imports.indexOf(d.name)>-1)
{
colorTarget(data.name);
colorIncomingLink(data.name,d.name);
}
});
})
.开启(“鼠标出”,功能(d)
{
d3.选择全部(“.node”)。样式(“填充”、“黑色”);
d3.选择全部(“.link”).样式(“笔划”、“钢蓝”);
}) 
.append(“文本”)
.attr(“dx”,函数(d){返回d.x<180?8:-8;})
.attr(“dy”,“.31em”)
.attr(“文本锚定”,函数(d){返回d.x<180?“开始”:“结束”})
.attr(“transform”,函数(d){返回d.x<180?null:“rotate(180)”;})
.text(函数(d){return d.key;});
//从类名惰性地构造包层次结构。
函数包层次结构(类){
var-map={};
函数查找(名称、数据){
var node=map[name],i;
如果(!节点){
node=map[name]=data | |{name:name,子项:[]};
如果(名称、长度){
node.parent=find(name.substring(0,i=name.lastIndexOf(“.”));
node.parent.children.push(节点);
node.key=name.substring(i+1);
}
}
返回节点;
}
类。forEach(函数(d){
查找(d.name,d);
});
返回映射[“”];
}
//返回给定节点数组的导入列表。
函数包导入(节点){
var-map={},
进口=[];
//计算从名称到节点的映射。
nodes.forEach(函数(d){
map[d.name]=d;
});
//对于每个导入,构造从源节点到目标节点的链接。
nodes.forEach(函数(d){
if(d.imports)d.imports.forEach(函数(i){
push({source:map[d.name],target:map[i]});
});
});
退货进口;
}
函数colorIncomingLink(src、tgt){
var-link=d3.sel