d3.js - TopoJSON ‹‹properties›› 字段，如何使用 d3.js 获取值？

Answer 1

You appear to be making one large map, not a series of path objects representing countries. Try this:

d3.json("map_topo.json", function(error, map) {
    svg.selectAll("path")
       .data(topojson.feature(us, us.objects.counties).features)
       .enter()
       .append("path")
       .attr("d", path)
       .style("fill", function(d) {
           if (d.properties.region == "XYZ")
               {return "red"}
           else {return "gray"}
       });

I can't be sure this will work without seeing the TopoJSON file, but basically you need a topojson method that will produce an array.

See the choropleth map example for a good example: The states are mapped as one path with .mesh() while the counties are mapped as individual objects like the code above.