javascript - Chart.js 折线图数据不显示

Question

我试图在 ASP.net 项目中使用 Chart.js 制作折线图，但没有任何数据显示:/image/vFcjT.png这是我的代码:

<script src="~/Scripts/Chart.js"></script>
<div>
    <canvas id="CO2Chart" width="800" height="450"></canvas>
</div>

<script>
    var CO2data = {
        labels: [1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019],
        datasets: {
            data: [315.97, 316.91, 317.64, 318.45, 318.99, 319.62, 320.04, 321.38, 322.16, 323.04, 324.62, 325.68, 326.32, 327.45, 329.68, 330.18, 331.11, 332.04, 333.83, 335.4, 336.84, 338.75, 340.11, 341.45, 343.05, 344.65, 346.12, 347.42, 349.19, 351.57, 353.12, 354.39, 355.61, 356.45, 357.1, 358.83, 360.82, 362.61, 363.73, 366.7, 368.38, 369.55, 371.14, 373.28, 375.8, 377.52, 379.8, 381.9, 383.79, 385.6, 387.43, 389.9, 391.65, 393.85, 396.52, 398.65, 400.83, 404.24, 406.55, 408.52, 411.44],
            label: "CO2 Atmospheric Concentration",
            fill: true,
            lineTension: 0.8,
            borderColor: "#000000",
            backgroundColor: "#000000",
            borderWidth: 5

        }
    }
    var CO2options = {
        scales: {
            yAxes: [{
                ticks: {
                    beginAtZero: true,
                    min: 300,
                    max: 475,
                    stepsize: 5
                }
            }]
        }
    }
    var ctx = document.getElementById('CO2Chart').getContext('2d');
    var CO2Chart = new Chart(ctx, {
        type: "line",
        data: CO2data,
        options: CO2options
    }
    );

Answer 1

问题是在CO2data内部，您没有将datasets定义为数组。它应该如下所示:

var CO2data = {
  labels: [...],
  datasets: [{
    ...
  }]
};

For further details, consult Dataset Configuration from Chart.js documentation.

请查看下面修改后的代码。

var CO2data = {
  labels: [1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019],
  datasets: [{
    data: [315.97, 316.91, 317.64, 318.45, 318.99, 319.62, 320.04, 321.38, 322.16, 323.04, 324.62, 325.68, 326.32, 327.45, 329.68, 330.18, 331.11, 332.04, 333.83, 335.4, 336.84, 338.75, 340.11, 341.45, 343.05, 344.65, 346.12, 347.42, 349.19, 351.57, 353.12, 354.39, 355.61, 356.45, 357.1, 358.83, 360.82, 362.61, 363.73, 366.7, 368.38, 369.55, 371.14, 373.28, 375.8, 377.52, 379.8, 381.9, 383.79, 385.6, 387.43, 389.9, 391.65, 393.85, 396.52, 398.65, 400.83, 404.24, 406.55, 408.52, 411.44],
    label: "CO2 Atmospheric Concentration",
    fill: true,
    lineTension: 0.8,
    borderColor: "#000000",
    backgroundColor: "#000000",
    borderWidth: 5
  }]
};

var CO2options = {
  scales: {
    yAxes: [{
      ticks: {
        beginAtZero: true,
        min: 300,
        max: 475,
        stepsize: 5
      }
    }]
  }
};

var ctx = document.getElementById('CO2Chart').getContext('2d');
var CO2Chart = new Chart(ctx, {
  type: "line",
  data: CO2data,
  options: CO2options
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.min.js"></script>
<div>
    <canvas id="CO2Chart" width="800" height="450"></canvas>
</div>