如何在Google Line Chart中动态更改线宽？

Question

我有一个复杂的折线图，想要在数据集上移动鼠标时突出显示（变胖）线条。事件＆＃34;选择＆＃34;和＆＃34; onmouseover＆＃34;我可以捕获，但如何动态更改数据集的线宽？或者是否还有其他可能突出显示所选行？

Answer 1

根据Customizing Lines，Google Chart中的行可以通过两种略有不同的方式进行自定义：使用colors选项更改图表调色板，或使用series选项指定特定系列的颜色。

以下示例演示如何突出显示选择事件的行：

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google.load('visualization', '1.1', { packages: ['corechart'] });
google.setOnLoadCallback(drawChart);

function drawChart() {

    var data = new google.visualization.DataTable();
    data.addColumn('number', 'Day');
    data.addColumn('number', 'Guardians of the Galaxy');
    data.addColumn('number', 'The Avengers');
    data.addColumn('number', 'Transformers: Age of Extinction');

    data.addRows([
        [1, 37.8, 80.8, 41.8],
        [2, 30.9, 69.5, 32.4],
        [3, 25.4, 57, 25.7],
        [4, 11.7, 18.8, 10.5],
        [5, 11.9, 17.6, 10.4],
        [6, 8.8, 13.6, 7.7],
        [7, 7.6, 12.3, 9.6],
        [8, 12.3, 29.2, 10.6],
        [9, 16.9, 42.9, 14.8],
        [10, 12.8, 30.9, 11.6],
        [11, 5.3, 7.9, 4.7],
        [12, 6.6, 8.4, 5.2],
        [13, 4.8, 6.3, 3.6],
        [14, 4.2, 6.2, 3.4]
    ]);

    var options = {
        chart: {
            title: 'Box Office Earnings in First Two Weeks of Opening',
            subtitle: 'in millions of dollars (USD)'
        },
        series: {
            0: { lineWidth: 1 },
            1: { lineWidth: 1 },
            2: { lineWidth: 1 }
        },
        width: 900,
        height: 500
    };

    var chart = new google.visualization.LineChart(document.getElementById('chart'));
    google.visualization.events.addListener(chart, 'select', function() { highlightLine(chart,data, options); });

    chart.draw(data, options);
}


function highlightLine(chart,data,options) {
    var selectedLineWidth = 4;
    var selectedItem = chart.getSelection()[0];
    //reset series line width to default value
    for(var i in options.series) {
        options.series[i].lineWidth = 1;
    }
    options.series[selectedItem.column-1].lineWidth = selectedLineWidth; //set selected line width
    chart.draw(data, options);   //redraw
}

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<script type="text/javascript" src="https://www.google.com/jsapi"></script>
<div id="chart"></div>

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