angular 图表中显示未定义的图例

Question

我正在使用 angular-chart.js 在我的应用程序中绘制图表。但我面临一个问题。图表图例显示 未定义 而不是标签。

我的js代码：

        $scope.labels_std = ['Total Students', 'Submitted fee', 'Has to submit'];
        $scope.options = {legend: {display: true, position: 'bottom'}};
        $scope.colors = ['#4D5360', '#949FB1', '#97BBCD'];
        $scope.data_std = [
                    $scope.allCount.students, 
                    $scope.allCount.fees, 
                    $scope.allCount.students - $scope.allCount.fees
                ];

标记为:

<canvas id="bar" class="chart chart-bar" chart-labels="labels_std" chart-data="data_std" chart-colors="colors" chart-options="options"></canvas>

但是结果是这样的：

Answer 1

它显示 undefined 因为您还没有为数据集定义 label 属性。

您需要在 $scope.datasetOverride 模型中为每个数据集设置 label 属性。另外，在您的视图标记中为其添加指令。

ᴡᴏʀᴋɪɴɢ ᴇxᴀᴍᴘʟᴇ

var app = angular.module('app', ['chart.js']);

app.controller("BarCtrl", function($scope) {
   $scope.labels = ['Total Students', 'Submitted fee', 'Has to submit'];
   $scope.colors = ['#4D5360', '#949FB1', '#97BBCD'];
   $scope.std = 65, $scope.fee = 59, $scope.nfee = 80;
   $scope.data = [
      [$scope.std, $scope.fee, $scope.nfee],
      [$scope.std, $scope.fee, $scope.nfee],
      [$scope.std, $scope.fee, $scope.nfee]
   ];
   $scope.options = {
      legend: {
         display: true
      }
   }
   $scope.datasetOverride = [{
      label: 'My First Dataset'
   }, {
      label: 'My Second Dataset'
   }, {
      label: 'My Third Dataset'
   }];
});

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.4/angular.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
<script src="https://cdn.jsdelivr.net/angular.chartjs/latest/angular-chart.min.js"></script>
<div ng-app="app" ng-controller="BarCtrl">
   <canvas id="bar" class="chart chart-bar" chart-data="data" chart-colors="colors" chart-labels="labels" chart-series="series" chart-options="options" chart-dataset-override="datasetOverride"></canvas>
</div>

Answer 2

我通过我曾经在互联网上找到的一个函数解决了这个问题，该函数寻找图例标签上的省略号。

您只需从您的选项->图例对象中调用该函数

$scope.labels_std = ['Total Students', 'Submitted fee', 'Has to submit'];
$scope.options = {legend: {
    display: true, 
    position: 'bottom',
    labels: {
        generateLabels: function(chart){
            var dataset = chart.data.datasets[0];
            var arcOpts = chart.options.elements.arc;

            //iterate the labels to return legend item interface 
            return chart.data.labels.map(function(label, i) {
                return {
                    text: label,
                    //lines below to emulate the default legend behaviour
                    fillStyle: Chart.helpers.getValueAtIndexOrDefault(dataset.backgroundColor, i , arcOpts.backgroundColor),
                    strokeStyle: Chart.helpers.getValueAtIndexOrDefault(dataset.borderColor, i , arcOpts.borderColor),
                    lineWidth: Chart.helpers.getValueAtIndexOrDefault(dataset.borderWidth, i , arcOpts.borderWidth),
                    hidden: isNaN(dataset.data[i]) || chart.getDatasetMeta(0).data[i].hidden,
                    index: i
                };
            });
        }
    }
}};

$scope.colors = ['#4D5360', '#949FB1', '#97BBCD'];

$scope.data_std = [
    $scope.allCount.students, 
    $scope.allCount.fees, 
    $scope.allCount.students - $scope.allCount.fees
];

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