使用Chart.js插件在.NET-6 Razor页面中实现条形图

4uqofj5v 于 2022-11-23 发布在 Chart.js

关注(0)|答案(1)|浏览(169)

图表正在显示，但垂直条未显示。数据来自处理程序，但无法分配到变量“data：data. datasets”。请帮助我。*
模型类别
ChartVM.cs*用于定义图表显示的属性 *

public class ChartVM
{
   public List<string> Labels{get;set;}
   public List<DataSetRow> Datasets{get;set;}
        
}
public class DataSetRow
{
   public List<int> Data{get;set;}
   public string BackgroundColor { get;set;}
   public string Color { get; set; }
}

图表演示.cs

public JsonResult OnGetBarChart()
    {
            var vm = new ChartVM();
            vm.Labels = new List<string>();
            vm.Datasets = new List<DataSetRow>();

            var result = context.CountryPopulations.ToList();
            vm.Labels = result.Select(x => x.Name).ToList();

            var ds1 = new DataSetRow
            {
                BackgroundColor = "#f2f2f2",
                Color = "#24248f",
                Data = result.Select(x => x.Male).ToList()
            };
            var ds2 = new DataSetRow
            {
                BackgroundColor = "#f2f2f2",
                Color = "#ff0080",
                Data = result.Select(x => x.Female).ToList()
            };
            vm.Datasets.Add(ds1);
            vm.Datasets.Add(ds2);
            return new JsonResult(vm);

     }

图表演示.cshtml
HTML代码

<div>
    <canvas id="myChart" style="max-height:400px; max-width:500px"></canvas>
</div>

Java脚本

<script src="~/lib/jquery/dist/jquery.js"></script>
    <script src="~/js/chart.min.js" asp-append-version="true"></script>
    <script type="text/javascript">
        $(document).ready(function () {
            BarChart();
        });
        function BarChart() {
            var XaxisTitle = 'Colour Bar';
            var Yaxistitle = 'Rupees';
            var legendTitle = 'Months';
            const ctx = document.getElementById('myChart');
            debugger;
            $.ajax({
                type:'GET',
                url:'?handler=BarChart',
                data:{},
                success:function(data){
                    new Chart(ctx, {
                        type: 'bar',
                        data: {
                            labels:data.labels,
                            datasets: [{
                                label: legendTitle,
                                data:data.datasets,
                                borderWidth: 1,                                                        
                            }]
                        },
                        options: {
                            scales: {
                                x: {
                                    display: true,
                                    beginAtZero: true,
                                    title: {
                                        display: true,
                                        text: XaxisTitle,
                                        color: '#911',
                                        font: {
                                            family: 'Comic Sans MS',
                                            size: 20,
                                            weight: 'bold',
                                            lineHeight: 1.2,
                                        },
                                        padding: { top: 20, left: 0, right: 0, bottom: 0 }
                                    }
                                },

                                y: {
                                    display: true,
                                    title: {
                                        display: true,
                                        text: Yaxistitle,
                                        color: '#191',
                                        font: {
                                            family: 'Times',
                                            size: 20,
                                            style: 'normal',
                                            lineHeight: 1.2
                                        },
                                        padding: { top: 30, left: 0, right: 0, bottom: 0 }
                                    }
                                }
                            }
                        }
                    });
                },
                error:function(){
                    alert('Something went wrong!!');
                }
            });

            

        }
    </script>

查看输出图像垂直条未显示

chart.js

来源：https://stackoverflow.com/questions/74500027/implementing-bar-chart-in-net-6-razor-pages-using-chart-js-plugin

1条答案

按热度按时间

pepwfjgg1#

但它不能赋值给变量“data：data.datasets”
错误就在这里：

datasets: [{
            label: legendTitle,
            data:data.datasets,
            borderWidth: 1,                                                        
          }]

chartjs中的单个数据集是具有数据点和选项的复杂对象。
因此，在提供的示例中，您尝试将数据集串传递给data points属性（基元整数值数组）。
快速修复：

data: {
       labels:data.labels,
       datasets: [...data.datasets]                           
       }

更改颜色并从here中删除数据。
显示排名前10位的国家：

public JsonResult OnGetBarChart()
{
    var vm = new ChartVM();
    vm.Datasets = new List<DataSetRow>();

    var result = context.Populations.OrderByDescending(x => x.TotalPop).Take(10).ToList();
    vm.Labels = result.Select(x => x.Name).ToList();

    var ds1 = new DataSetRow
    {
        Label = "Male",
        BackgroundColor = "#ffA500",
        BorderColor = "#ffA500",
        Data = result.Select(x => x.MalePop).ToList()
    };
    var ds2 = new DataSetRow
    {
        Label = "Female",
        BackgroundColor = "#00B612",
        BorderColor = "#00B612",
        Data = result.Select(x => x.FemalePop).ToList()
    };
    vm.Datasets.Add(ds1);
    vm.Datasets.Add(ds2);

    return new JsonResult(vm);
}

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使用Chart.js插件在.NET-6 Razor页面中实现条形图

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