Question

我想将我的图表setTimeout函数添加到更新的数据中。下面列出了代码，但控制台正在说未捕获的TypeError：无法读取属性＆＃39;数据＆＃39;未定义＆＃34; 如何访问数据数组？并把我的价值观？错误是在此代码的末尾记录。在var ChartLine中。或者，如果您有任何其他想法如何更新动态数据，请分享您的答案

 var ctx = document.getElementById('chart').getContext("2d");

    var myChart = new Chart(ctx, {
        type: 'line',
        data: {
            labels: ["JAN", "FEB", "MAR", "APR", "MAY", "JUN", "JUL"],
            datasets: [{
                label: "Data",
                borderColor: gradientStroke,
                pointBorderColor: gradientStroke,
                pointBackgroundColor: gradientStroke,
                pointHoverBackgroundColor: gradientStroke,
                pointHoverBorderColor: gradientStroke,
                pointBorderWidth: 5,
                pointHoverRadius: 5,
                pointHoverBorderWidth: 1,
                pointRadius: 3,
                fill: true,
                backgroundColor: gradientFill,
                borderWidth: 2,
                data: [50, 80, 130, 65, 100, 66, 86],
            }]
        },
        options: {
            legend: {
                position: "top"
            },
            scales: {
                yAxes: [{
                    ticks: {
                        fontColor: "rgba(255,255,255,0.5)",
                        fontStyle: "bold",
                        beginAtZero: true,
                        maxTicksLimit: 5,
                        padding: 20
                    },
                    gridLines: {
                        drawTicks: false,
                        display: false
                    }

                }],
                xAxes: [{
                    gridLines: {
                        zeroLineColor: "rgba(255,255,255,0.5)"
                    },
                    ticks: {
                        padding: 20,
                        fontColor: "rgba(255,255,255,0.5)",
                        fontStyle: "bold"
                    }
                }]
            }
        }
    });

   setTimeout(function addData(chart, label, data) {
        chart.data.labels.push(label);
        chart.data.datasets.forEach((dataset) => {
            dataset.data.push([45, 45, 45, 15, 3]);
        });
        chart.update();
    }, 2000);

感谢您的帮助

Answer 1

您应该按如下方式更新图表数据：

setTimeout(function() {
   addData(myChart, [45, 50, 30, 34, 61, 53, 42], 0);
}, 2000);

function addData(chart, data, datasetIndex) {
   chart.data.datasets[datasetIndex].data = data;
   chart.update();
}

工作示例

var gradientStroke = 'rgba(0, 119, 220, 0.6)',
    gradientFill = 'rgba(0, 119, 220, 0.4)';

var ctx = document.getElementById('chart').getContext("2d");

var myChart = new Chart(ctx, {
   type: 'line',
   data: {
      labels: ["JAN", "FEB", "MAR", "APR", "MAY", "JUN", "JUL"],
      datasets: [{
         label: "Data",
         borderColor: gradientStroke,
         pointBorderColor: gradientStroke,
         pointBackgroundColor: gradientStroke,
         pointHoverBackgroundColor: gradientStroke,
         pointHoverBorderColor: gradientStroke,
         pointBorderWidth: 5,
         pointHoverRadius: 5,
         pointHoverBorderWidth: 1,
         pointRadius: 3,
         fill: true,
         backgroundColor: gradientFill,
         borderWidth: 2,
         data: [50, 80, 130, 65, 100, 66, 86],
      }]
   },
   options: {
      responsive: false,
      legend: {
         position: "top"
      },
      scales: {
         yAxes: [{
            ticks: {
               fontColor: "rgba(255,255,255,0.5)",
               fontStyle: "bold",
               beginAtZero: true,
               maxTicksLimit: 5,
               padding: 20
            },
            gridLines: {
               drawTicks: false,
               display: false
            }

         }],
         xAxes: [{
            gridLines: {
               zeroLineColor: "rgba(255,255,255,0.5)"
            },
            ticks: {
               padding: 20,
               fontColor: "rgba(255,255,255,0.5)",
               fontStyle: "bold"
            }
         }]
      }
   }
});


setTimeout(function() {
   addData(myChart, [45, 50, 30, 34, 61, 53, 42], 0);
}, 2000);

function addData(chart, data, datasetIndex) {
   chart.data.datasets[datasetIndex].data = data;
   chart.update();
}

* { background: #111 }

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
<canvas id="chart" width="350" height="200"></canvas>

Chart.js更新数据

1 个答案: