javascript - 隐藏 CanvasJS 图中的所有系列按钮(javascript foreach 用法)

Question

这个问题与 CanvasJS 相关，但可能任何纯 JavaScript 专家都可以提供帮助。

我需要一个按钮来隐藏/取消隐藏canvasjs图中的所有元素。有一个工作代码可以使用数组索引隐藏元素:

chart.options.data[0].visible = !chart.options.data[0].visible;

我正在尝试遍历数组，但它不起作用，显然我的代码是错误的:

chart.options.data.forEach(visible = !visible);

我该如何解决这个问题？

完整的代码片段是:

 var chart = new CanvasJS.Chart("chartContainer",
    {
      title:{
      text: "Test Button to Hide All Series"  
      },
      
      legend: {
            cursor: "pointer",
            itemclick: function (e) {
                //console.log("legend click: " + e.dataPointIndex);
                //console.log(e);
                if (typeof (e.dataSeries.visible) === "undefined" || e.dataSeries.visible) {
                    e.dataSeries.visible = false;
                } else {
                    e.dataSeries.visible = true;
                }
 
                e.chart.render();
            }
        },
      
      data: [
      { 
        showInLegend: true,
        type: "line",
        dataPoints: [
        { x: 10, y: 5 },
        { x: 20, y: 9},
        { x: 30, y: 17 },
        { x: 40, y: 32 },
        { x: 50, y: 22 },
        { x: 60, y: 14 },
        { x: 70, y: 25 },
        { x: 80, y: 18 },
        { x: 90, y: 20}
      
        ]
      },
        {
        showInLegend: true,
        type: "line",
        dataPoints: [
        { x: 10, y: 31 },
        { x: 20, y: 35},
        { x: 30, y: 30 },
        { x: 40, y: 35 },
        { x: 50, y: 35 },
        { x: 60, y: 38 },
        { x: 70, y: 38 },
        { x: 80, y: 34 },
        { x: 90, y: 44}
      
        ]
      },
        {
        showInLegend: true,
        type: "line",
        dataPoints: [
        { x: 10, y: 25 },
        { x: 20, y: 30},
        { x: 30, y: 20 },
        { x: 40, y: 45 },
        { x: 50, y: 30 },
        { x: 60, y: 10 },
        { x: 70, y: 15 },
        { x: 80, y: 18 },
        { x: 90, y: 20}
      
        ]
      }
      ]
    });
 
    chart.render();
    
 document.getElementById("showAllSeries").onclick =  function(){
   //Works for a single element using index:
   chart.options.data[0].visible = !chart.options.data[0].visible;
   //Doesn't work, need to modify
   //chart.options.data.forEach(visible = !visible);
   chart.render();
 };

<script src="https://canvasjs.com/assets/script/canvasjs.min.js"></script>
<br/>
<div id="chartContainer" style="height: 300px; width: 100%;"></div>
<center><button id= "showAllSeries" style= "margin: 10px;">Show/Hide All series</button></center>

向上:找到了 for 循环的解决方案:

   for (var i = 0; i < chart.options.data.length; i++) {
   chart.options.data[i].visible = !chart.options.data[i].visible;
   }

但仍然有趣的是它应该如何与foreach一起使用

Answer 1

forEach 是一个数组方法，可用于对数组中的每个元素执行函数。另一方面，for 是一个更灵活的循环。

在您的情况下，您可以使用 for 或 forEach 隐藏所有 dataSeries onclick 按钮。检查下面的代码:

var chart = new CanvasJS.Chart("chartContainer", {
	title:{
		text: "Test Button to Hide All Series"  
	},

	legend: {
		cursor: "pointer",
		itemclick: function (e) {
			if (typeof (e.dataSeries.visible) === "undefined" || e.dataSeries.visible) {
				e.dataSeries.visible = false;
			} else {
				e.dataSeries.visible = true;
			}
			e.chart.render();
		}
	},

	data: [
		{ 
		showInLegend: true,
		type: "line",
		dataPoints: [
			{ x: 10, y: 5 },
			{ x: 20, y: 9 },
			{ x: 30, y: 17 },
			{ x: 40, y: 32 },
			{ x: 50, y: 22 },
			{ x: 60, y: 14 },
			{ x: 70, y: 25 },
			{ x: 80, y: 18 },
			{ x: 90, y: 20 }
		]
		},
		{
		showInLegend: true,
		type: "line",
		dataPoints: [
			{ x: 10, y: 31 },
			{ x: 20, y: 35 },
			{ x: 30, y: 30 },
			{ x: 40, y: 35 },
			{ x: 50, y: 35 },
			{ x: 60, y: 38 },
			{ x: 70, y: 38 },
			{ x: 80, y: 34 },
			{ x: 90, y: 44 }
		]
		},
		{
		showInLegend: true,
		type: "line",
		dataPoints: [
			{ x: 10, y: 25 },
			{ x: 20, y: 30 },
			{ x: 30, y: 20 },
			{ x: 40, y: 45 },
			{ x: 50, y: 30 },
			{ x: 60, y: 10 },
			{ x: 70, y: 15 },
			{ x: 80, y: 18 },
			{ x: 90, y: 20 }
		]
		}
	]
});

chart.render();

document.getElementById("showAllSeries").onclick =  function(){
	chart.options.data.forEach(function(dataSeries) {
  	if (typeof (dataSeries.visible) === "undefined" || dataSeries.visible) {
			dataSeries.visible = false;
		} else {
			dataSeries.visible = true;
		}
	});
	/*var dataSeries;
  	for(var i = 0; i < chart.data.length; i++){
  	dataSeries = chart.options.data[i];
		if (typeof (dataSeries.visible) === "undefined" || dataSeries.visible) {
			dataSeries.visible = false;
		} else {
			dataSeries.visible = true;
		}
	}*/  
	chart.render();
};

<script src="https://canvasjs.com/assets/script/canvasjs.min.js"></script>
<div id="chartContainer" style="height: 260px; width: 100%;"></div>
<center><button id= "showAllSeries" style= "margin: 10px;">Show/Hide All series</button></center>