使用chartjs-plugin-zoom为chartjs的图表添加缩放事件处理程序 [英] Add zoom event handler to charts for chartjs with chartjs-plugin-zoom

问题描述

但是，我不想首先显示重置缩放"按钮.相反，我想先隐藏它，然后监听缩放事件(在 chartjs-plugin-zoom 中，事件是鼠标滚轮和触摸屏的捏合)来显示它.

所以问题是，chartjs 中是否有一种方法可以使用 chartjs-plugin-zoom 向图表添加缩放事件处理程序(滚轮和捏合事件)?谢谢.

解决方案

很遗憾，您不能向图表添加鼠标滚动事件，因为 chartjs-plugin-zoom 将默认阻止该事件.

但是，您可以使用以下图表插件，它将为您完成工作......

插件:[{beforeDraw:函数(c){var reset_zoom = document.getElementById("reset_zoom");//复位按钮var ticks = c.scales['x-axis-0'].ticks.length;//x轴刻度数组var 标签 = c.data.labels.length;//标签数组if (ticks 

添加此插件，然后添加您的图表选项.

基本上，chartjs-plugin-zoom 的工作方式是，它在鼠标滚动时从/向 ticks 数组中删除/添加元素，并且上面的插件将检查为此，此后相应地显示/隐藏 rest zoom 按钮.

ᴡᴏʀᴋɪɴɢ ᴇxᴀᴍᴘʟᴇ ⧩

var ctx = document.getElementById("myChart");var myChart = 新图表(ctx，{类型:'酒吧'，数据: {标签:[红色"、蓝色"、黄色"、绿色"、紫色"、橙色"]、数据集:[{label: '# of Votes',数据:[12, 19, 3, 5, 2, 3]}]},选项: {平底锅: {启用:真，模式:'x'，},飞涨: {启用:真，模式:'x'，}},插件:[{beforeDraw:函数(c){var reset_zoom = document.getElementById("reset_zoom");//复位按钮var ticks = c.scales['x-axis-0'].ticks.length;//x轴刻度数组var 标签 = c.data.labels.length;//标签数组if (ticks 

.myChartDiv {最大宽度:600px；最大高度:400px；}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script><script src="https://npmcdn.com/Chart.Zoom.js@0.3.0/Chart.Zoom.min.js"></script><div class="myChartDiv"><canvas id="myChart" width="600" height="400"></canvas>

<button id="reset_zoom" hidden>重置缩放</button>

chartjs-plugin-zoom is a zoom and pan plugin for Chart.js

You can call chart.resetZoom() to programmatically resets the zoom to the default state. See this example on jsfiddle.

HTML:

<div class="myChartDiv">
    <canvas id="myChart" width="600" height="400"></canvas>
</div>

<button id="reset_zoom">
    Reset zoom
</button>

JavaScript:

var ctx = document.getElementById("myChart");
var myChart = new Chart(ctx, {
    type: 'bar',
    data: {
        labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
        datasets: [{
            label: '# of Votes',
            data: [12, 19, 3, 5, 2, 3]
        }]
    },
    options: {
        pan: {
            enabled: true,
            mode: 'x',
        },
        zoom: {
            enabled: true,                      
            mode: 'x',
        }
    }
});

$('#reset_zoom').click(function(){
    myChart.resetZoom();
});

And it looks like:

However, I don't want to show the Reset zoom button in the first place. Instead, I would like to hide it first, and then listen for a zoom event (In chartjs-plugin-zoom the event is mouse wheel and pinch for touch screens) to show it.

So the question is, is there a way in chartjs with chartjs-plugin-zoom to add a zoom event handler (wheel and pinch events) to a chart? Thanks.

解决方案

Unfortunately, you can not add mouse scroll event to the chart, as the chartjs-plugin-zoom will prevent that by default.

However, you can use the following chart plugin, which will get the job done for you ...

plugins: [{
   beforeDraw: function(c) {
      var reset_zoom = document.getElementById("reset_zoom"); //reset button
      var ticks = c.scales['x-axis-0'].ticks.length; //x-axis ticks array
      var labels = c.data.labels.length; //labels array
      if (ticks < labels) reset_zoom.hidden = false;
      else reset_zoom.hidden = true;
   }
}]

add this plugin followed by your chart options.

Basically, the way chartjs-plugin-zoom works is, it removes/adds elements from/to the ticks array on mouse scroll, and the above plugin will check for that, henceforth show / hide the rest zoom button accordingly.

ᴡᴏʀᴋɪɴɢ ᴇxᴀᴍᴘʟᴇ ⧩

var ctx = document.getElementById("myChart");
var myChart = new Chart(ctx, {
   type: 'bar',
   data: {
      labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
      datasets: [{
         label: '# of Votes',
         data: [12, 19, 3, 5, 2, 3]
      }]
   },
   options: {
      pan: {
         enabled: true,
         mode: 'x',
      },
      zoom: {
         enabled: true,
         mode: 'x',
      }
   },
   plugins: [{
      beforeDraw: function(c) {
         var reset_zoom = document.getElementById("reset_zoom"); //reset button
         var ticks = c.scales['x-axis-0'].ticks.length; //x-axis ticks array
         var labels = c.data.labels.length; //labels array
         if (ticks < labels) reset_zoom.hidden = false;
         else reset_zoom.hidden = true;
      }
   }]
});

$('#reset_zoom').click(function() {
   myChart.resetZoom();
});

.myChartDiv {
   max-width: 600px;
   max-height: 400px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
<script src="https://npmcdn.com/Chart.Zoom.js@0.3.0/Chart.Zoom.min.js"></script>
<div class="myChartDiv">
   <canvas id="myChart" width="600" height="400"></canvas>
</div>
<button id="reset_zoom" hidden>
   Reset zoom
</button>

这篇关于使用chartjs-plugin-zoom为chartjs的图表添加缩放事件处理程序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！