创建 IF 以更改 chart.js 条形颜色

Question

我是 JavaScript 新手，我正在使用 chart.js 创建一些数据可视化，我需要将整个条形的颜色更改为不同的值，我目前的代码如下，但我不能让它工作，这没有给我任何错误，所以我不知道要走了。

var dData1 = 90; ///////CARREGAR DADOS  DE FACTURAÇÃO (for developer)
var dData2 = 70; ///////CARREGAR DADOS  DE FACTURAÇÃO (for developer)

    var barChartData = {
            labels: ["MÊS", "ANO"],
            datasets: [{
                fillColor: "#f37c8a",
                strokeColor: "none",
                data: [dData1, dData2]
                }]
        }

    if (dData1 < 75)
        {
            barChartData.datasets[0].fillColor = "#f37c8a";
        }
         else if (dData1 > 76 && dData1 < 85) 
        {
            barChartData.datasets[0].fillColor = "#f3e97c";
        } 
        else if (dData1 > 86)
        {
            barChartData.datasets[0].fillColor = "#9ae27d";
        } else 
        {
            barChartData.datasets[0].fillColor = "#fff";
        };  

    if (dData2 < 75)
        {
            barChartData.datasets[0].fillColor = "#f37c8a";
        }
         else if (dData2 > 76 && dData1 < 85) 
        {
            barChartData.datasets[0].fillColor = "#f3e97c";
        } 
        else if (dData2 > 86)
        {
            barChartData.datasets[0].fillColor = "#9ae27d";
        } else 
        {
            barChartData.datasets[0].fillColor = "#fff";
        };

Answer 1

您需要为bars在生成图表后设置颜色。您需要设置 fillColor、highlightFill 和 _saved.fillColor（Chart.js 用于在工具提示悬停后恢复条形颜色）

所以你需要类似的东西

if (dData1 < 75)
{
    barChart.datasets[0].bars[0].fillColor = barChart.datasets[0].bars[0].highlightFill = barChart.datasets[0].bars[0]._saved.fillColor = "#f37c8a";
}
else if (dData1 > 76 && dData1 < 85) 
{
    barChart.datasets[0].bars[0].fillColor = barChart.datasets[0].bars[0].highlightFill = barChart.datasets[0].bars[0]._saved.fillColor = "#f3e97c";
} 
else if (dData1 > 86)
{
    barChart.datasets[0].bars[0].fillColor = barChart.datasets[0].bars[0].highlightFill = barChart.datasets[0].bars[0]._saved.fillColor = "#9ae27d";
} else 
{
    barChart.datasets[0].bars[0].fillColor = barChart.datasets[0].bars[0].highlightFill = barChart.datasets[0].bars[0]._saved.fillColor = "#fff";
};  

对于第一个块，barChart 是您的图表对象。请注意，上面的代码假定单个系列包含 2 个元素。

---

小提琴 - https://jsfiddle.net/2a86gqsa/

请注意，您在第二个块中有 dData1 < 85 - 我将其更改为 dData2 < 85。看到这 2 个块的大部分代码很常见，您可能希望将其移动到函数中。

Answer 2

解决了，我把图书馆里面的东西叫错了。

    var dData1 = 90; ///////CARREGAR DADOS  DE FACTURAÇÃO
    var dData2 = 70; ///////CARREGAR DADOS  DE FACTURAÇÃO

    var barChartData = {
            labels: ["MÊS", "ANO"],
            datasets: 

                 [{
                fillColor: "rgba(220,220,220,1)",
                strokeColor: "rgba(220,220,220,0.0)",
                highlightFill: "rgba(220,220,220,0.0)",
                highlightStroke: "rgba(220,220,220,0)",
                data: [dData1, dData2]
                }]
        }

    var ctx = document.getElementById("myChart").getContext("2d");
    var myChart = new Chart(ctx).Bar(barChartData, {
      responsive: true,
      barValueSpacing: 10
    });

    if (barChartData.datasets[0].data=[dData1] < 75)
        { 
            console.log("vermelho");
            myChart.datasets[0].bars[0].fillColor = "rgba(243,124,138,1.00)";
            myChart.update();
        }
         else if (dData1 > 76 && dData1 < 85) 
        {
            console.log("amarelo");
            myChart.datasets[0].bars[0].fillColor = "rgba(243,233,7,1.00)";
            myChart.update();
        } 
        else if (dData1 > 86)
        {
            console.log("verde");
            myChart.datasets[0].bars[0].fillColor = "rgba(154,226,125,1.00)";
            myChart.update();
        } else 
        {
            console.log("branco");
            myChart.datasets[0].bars[0].fillColor = "rgba(255,255,255,1)";
            myChart.update();
        };  



    if (barChartData.datasets[0].data=[dData2] < 75)
        { 
            console.log("vermelho2");
            myChart.datasets[0].bars[1].fillColor = "rgba(243,124,138,1.00)";
            myChart.update();
        }
         else if (dData2 > 76 && dData2 < 85) 
        {
            console.log("amarelo2");
            myChart.datasets[0].bars[1].fillColor = "rgba(243,233,7,1.00)";
            myChart.update();
        } 
        else if (dData2 > 86)
        {
            console.log("verde2");
            myChart.datasets[0].bars[1].fillColor = "rgba(154,226,125,1.00)";
            myChart.update();
        } else 
        {
            console.log("branco2");
            myChart.datasets[0].bars[1].fillColor = "rgba(255,255,255,1)";
            myChart.update();
        };