如何在折线图中始终显示工具提示

Question

我在谷歌搜索过，无法找到如何在折线图中显示工具提示。我正在使用angular-chart.js。

  $scope.labels = ["January", "February", "March", "April", "May", "June", "July"];
  $scope.series = ['Series A', 'Series B'];
  $scope.data = [
    [65, 59, 80, 81, 56, 55, 40],
    [28, 48, 40, 19, 86, 27, 90]
  ];
  $scope.onClick = function (points, evt) {
    console.log(points, evt);
  };
  $scope.datasetOverride = [{ yAxisID: 'y-axis-1' }, { yAxisID: 'y-axis-2' }];
  $scope.options = {
    scales: {
      yAxes: [
        {
          id: 'y-axis-1',
          type: 'linear',
          display: true,
          position: 'left'
        },
        {
          id: 'y-axis-2',
          type: 'linear',
          display: true,
          position: 'right'
        }
      ]
    }
  };
});

HTML

<canvas id="line" class="chart chart-line" chart-data="data"
chart-labels="labels" chart-series="series" chart-options="options"
chart-dataset-override="datasetOverride" chart-click="onClick">
</canvas>

我正在搜索类似的this，它会在工具提示上显示百分比。

我尝试过以下选项。（在angular-js问题中找到）。但它不起作用。

var options = {
      scaleShowLabelBackdrop : true,
      scaleShowLabels : true,
      scaleBeginAtZero : true,
      scaleLabel : "Percent",
      multiTooltipTemplate: "10% achieved"
}