Question

这是一个已经问过的问题，但没有一个解决方案适合我，所以再次提出。

1.我正在尝试根据某个阈值更改我的D3条形图中条形的颜色（如果条形超过y轴上的特定值，在这种情况下为30）如何更改酒吧的颜色到别的地方说蓝色。

我还想在y = 30处绘制一条水平线。

此数据是data.tsv文件

letter  frequency   attachdate
a   13  12-May-2016
b   14  11-May-2016

body {
  font: 10px sans-serif;
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.bar {
  fill: orange;
}

.bar:hover {
  fill: orangered ;
}

.x.axis path {
  display: none;
}

.d3-tip {
  line-height: 1;
  font-weight: bold;
  padding: 12px;
  background: rgba(0, 0, 0, 0.8);
  color: #fff;
  border-radius: 2px;
}

/* Creates a small triangle extender for the tooltip */
.d3-tip:after {
  box-sizing: border-box;
  display: inline;
  font-size: 10px;
  width: 100%;
  line-height: 1;
  color: rgba(0, 0, 0, 0.8);
  content: "\25BC";
  position: absolute;
  text-align: center;
}

/* Style northward tooltips differently */
.d3-tip.n:after {
  margin: -1px 0 0 0;
  top: 100%;
  left: 0;
}
</style>

var margin = {top: 40, right: 20, bottom: 160, left: 50},
    width = 960 - margin.left - margin.right,
    height = 600 - margin.top - margin.bottom;

var formatPercent = d3.format(".0%");

var x = d3.scale.ordinal()
    .rangeRoundBands([0, width], .1);

var y = d3.scale.linear()
    .range([height, 0]);

var xAxis = d3.svg.axis()
    .scale(x)
    .orient("bottom");

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left");

var tip = d3.tip()
  .attr('class', 'd3-tip')
  .offset([-10, 0])
  .html(function(d) {
    return "<strong>Number of days:</strong> <span style='color:red'>" + d.frequency + "</span>"+"</b><br/>Attach date: " + d.attachdate;
  })

var svg = d3.select("body").append("svg")
.attr("align","center")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")

    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

svg.call(tip);

d3.tsv("data.tsv", type, function(error, data) {
  x.domain(data.map(function(d) { return d.letter; }));
  y.domain([0, 60]);

  svg.append("g")
   .attr("class", "x axis")
   .attr("transform", "translate(0,400)")
   .call(xAxis)
     .selectAll("text")  
     .style("text-anchor", "end")
     .attr("dx", "-.8em")
     .attr("dy", ".15em")
     .attr("transform", "rotate(-65)");


  svg.append("g")
      .attr("class", "y axis")
      .call(yAxis)
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", ".71em")
      .style("text-anchor", "end")
      .text("Number of days");

  svg.selectAll(".bar")
      .data(data)
    .enter().append("rect")
      .attr("class", "bar")
      .attr("x", function(d) { return x(d.letter); })
      .attr("width", x.rangeBand())
      .attr("y", function(d) { return y(d.frequency); })
      .attr("height", function(d) { return height - y(d.frequency); })
      .on('mouseover', tip.show)
      .on('mouseout', tip.hide)
});


svg.append("text")
        .attr("x", (width / 2))       
        .attr("y", 0 - (margin.top / 2))
        .attr("text-anchor", "middle")  
        .style("font-size", "18px" ) 
        .style("text-decoration", "underline")  
        .style("fill", "red")
        .text("Some heading");


function type(d) {
  d.frequency = +d.frequency;
  return d;
}

</script>
</body>

Answer 1

任何不明白的理由：

public partial class UpdateFeedPage : ContentPage
    {
        public static List<FileObject> CurrentSelectedFile = new List<FileObject>();
        public static string PostText = "";

        public UpdateFeedPage()
        {
            InitializeComponent();
            Title = "New Update";
            UpdateFeedEditor.Text = PostText;
        }

        protected override void OnAppearing()
        {
            AttachedFilesListView.ItemsSource = CurrentSelectedFile;
            UpdateFeedEditor.Focus();
            base.OnAppearing();
        }

        async void onPostClicked(object sender, EventArgs e)
        {
            await Navigation.PopAsync();
        }

        async void onAttachFileClicked(object sender, EventArgs e)
        {
            await Navigation.PushAsync(new FilePickerPage());
        }
    }

等

Answer 2

正如@Stephen所说，你基本上可以利用class属性来管理你的酒吧的颜色。另一种方法是使用fill属性并使用函数返回所需的值。

svg.selectAll(".bar")
    .data(data)
    .enter().append("rect")
    .attr("class", "bar")
    .attr("x", function(d) { return x(d.letter); })
    .attr("width", x.rangeBand())
    .attr("y", function(d) { return y(d.frequency); })
    .attr("height", function(d) { return height - y(d.frequency); })
    .attr("fill", function(d) {
      if (d.frequency >= 30) {
        return 'red';
      }
      return 'green';
    });

至于你想画的线你可能会做这样的事情：

svg.append("line")
   .attr("x1", 0)
   .attr("y1", y(30))
   .attr("x2", width)
   .attr("y2", y(30))
   .style("stroke", "#828282")
   .attr('stroke-dasharray', '2,2')
   .attr('stroke-width', '1')

以下是一个代码与您的代码类似的plunker：https://plnkr.co/edit/3danSMezWDsbnJZXEUTH?p=preview

根据D3中的阈值保持值更改Bar的颜色

2 个答案: