为何不用Echarts

  • 相比Echarts及F2的复杂的设置,本插件几乎等于傻瓜式的配置。
  • Echarts在跨端使用更复杂,本插件只需要简单的两个<canvas>标签轻松区别搞定,代码整洁易维护。
  • Echarts在IOS端图表显示错位,只能引用网页解决。
  • 本插件打包后的体积相比Echarts小很多很多,所以性能更好
  • 如果您是uni-app初学者,那么强烈建议您使用uCharts,并且目前可以跨全端通用,减少工作量,增强一致性体验。
  • 图表样式均可自定义,懂js的都可以读懂插件源码,直接修改u-charts.js源码即可。
  • 本插件经过大量测试,反复论证并加以改造而成,请各位放心使用。

扫码体验:

 以下代码参考官方示例:/pages/basic/line/curve.vue,下载地址:https://ext.dcloud.net.cn/plugin?id=271

以曲线图为例介绍使用步骤:

1、将u-charts.js拷贝到components目录下

 2、引入组件

import uCharts from '@/components/u-charts/u-charts.js';

3、模板写法:

<view class="qiun-charts" >
            <!--#ifdef MP-ALIPAY -->
            <canvas canvas-id="canvasLineA" id="canvasLineA" class="charts" :width="cWidth*pixelRatio" :height="cHeight*pixelRatio" 
          :style="{'width':cWidth+'px','height':cHeight+'px'}" @touchstart="touchLineA"></canvas> <!--#endif--> <!--#ifndef MP-ALIPAY --> <canvas canvas-id="canvasLineA" id="canvasLineA" class="charts" @touchstart="touchLineA"></canvas> <!--#endif--> </view>

如果是支付宝小程序用上面那种,即

<view class="qiun-charts" >
            <!--#ifdef MP-ALIPAY -->
            <canvas canvas-id="canvasLineA" id="canvasLineA" class="charts" :width="cWidth*pixelRatio" :height="cHeight*pixelRatio" 
          :style="{'width':cWidth+'px','height':cHeight+'px'}" @touchstart="touchLineA"></canvas> <!--#endif--> </view>

支付宝以外用下面那种,即

<view class="qiun-charts" >
            <!--#ifndef MP-ALIPAY -->
            <canvas canvas-id="canvasLineA" id="canvasLineA" class="charts" @touchstart="touchLineA"></canvas>
            <!--#endif-->
        </view>

4、样式写法

.qiun-charts{
        width: 750upx; 
        height:500upx;
        background-color: #FFFFFF;
        }
    .charts{
        width: 750upx; 
        height:500upx;
        background-color: #FFFFFF;
        }

5、实例化方法

showLineA(canvasId,chartData){
                canvaLineA=new uCharts({
                    $this:_self,
                    canvasId: canvasId,
                    type: 'line',
                    fontSize:11,
                    padding:[15,20,0,15],
                    legend:{
                        show:true,
                        padding:5,
                        lineHeight:11, // 控制标题的行高
                        margin:0, // 控制标题的margin
                    },
                    dataLabel:true,
                    dataPointShape:true,
                    background:'#FFFFFF',
                    pixelRatio:_self.pixelRatio,
                    categories: chartData.categories,
                    series: chartData.series,
                    animation: true,
                    xAxis: {
                        type:'grid',
                        gridColor:'#CCCCCC',
                        gridType:'dash',
                        dashLength:8,
            boundaryGap:'justify'
                    },
                    yAxis: {
                        gridType:'dash',
                        gridColor:'#CCCCCC',
                        dashLength:8,
                        splitNumber:5,
                        format:(val)=>{return val.toFixed(0)+''}
                    },
                    width: _self.cWidth*_self.pixelRatio,
                    height: _self.cHeight*_self.pixelRatio,
                    extra: {
                        line:{
                            type: 'curve'
                        }
                    }
                });
                //下面是默认选中索引
                let cindex=3;
                //下面是自定义文案
                let textList=[{text:'我是一个标题',color:null},{text:'自定义1:值1',color:'#2fc25b'},{text:'自定义2:值2',color:'#facc14'},
                  {text:'自定义3:值3',color:'#f04864'}]; //下面是event的模拟,tooltip的Y坐标值通过这个mp.changedTouches[0].y控制 let tmpevent={mp:{changedTouches:[{x: 0, y: 80}]}}; setTimeout(()=>{ canvaLineA.showToolTip( tmpevent , { index:cindex, textList:textList }); },200) }, touchLineA(e) { canvaLineA.touchLegend(e); canvaLineA.showToolTip(e, { format: function (item, category) { return category + ' ' + item.name + ':' + item.data } }); },

数据模型中拷贝以下参数

data() {
            return {
                cWidth:'',
                cHeight:'',
                pixelRatio:1,
                textarea:''
            }
        },

6、在实际项目中,我们是从后台获取数据存入chartData中,并调用实例化方法。这里我们先在数据模型中给出chartData的默认值,并在onLoad中调用实例化方法

onLoad(options) {
            this.showLineA("canvasLineA",this.chartData)
        },

chartData数据示例:

{
    "categories":["2012","2013","2014","2015","2016","2017"],
    "series":[
        {"name":"成交量A","data":[35,8,25,37,4,20]}
    ]
}

7、在onLoad生命周期函数中初始化cWidth和cHeight,来控制图标的宽和高

this.cWidth=uni.upx2px(750);
            this.cHeight=uni.upx2px(500);

8、定义canvaLineA

var canvaLineA=null;

效果如下图所示

 完整代码如下:

<template>
    <view class="container">
        <view class="qiun-charts" >
            <!--#ifndef MP-ALIPAY -->
            <canvas canvas-id="canvasLineA" id="canvasLineA" class="charts" @touchstart="touchLineA"></canvas>
            <!--#endif-->
        </view>
    </view>
</template>

<script>
    import uCharts from '@/components/u-charts/u-charts.js';
  var canvaLineA=null;
export
default { data(){ return { cWidth:'', cHeight:'', pixelRatio:1, textarea:'', chartData:{ "categories":["2012","2013","2014","2015","2016","2017"], "series":[ {"name":"成交量A","data":[35,8,25,37,4,20]} ] } } }, onLoad(options) { console.log(options)this.cWidth = uni.upx2px(720); this.cHeight = uni.upx2px(420); this.showLineA("canvasLineA",this.chartData) }, methods:{ showLineA(canvasId,chartData){ canvaLineA=new uCharts({ $this:this, canvasId: canvasId, type: 'line', fontSize:11, padding:[15,20,0,15], legend:{ show:true, padding:5, lineHeight:11, margin:0, }, dataLabel:true, dataPointShape:true, background:'#FFFFFF', pixelRatio:this.pixelRatio, categories: chartData.categories, series: chartData.series, animation: true, xAxis: { type:'grid', gridColor:'#CCCCCC', gridType:'dash', dashLength:8, boundaryGap:'justify' }, yAxis: { gridType:'dash', gridColor:'#CCCCCC', dashLength:8, splitNumber:5, format:(val)=>{return val.toFixed(0)+'元'} }, width: this.cWidth*this.pixelRatio, height: this.cHeight*this.pixelRatio, extra: { line:{ type: 'curve' } } }); //下面是默认选中索引 let cindex=3; //下面是自定义文案 let textList=[{text:'我是一个标题',color:null},{text:'自定义1:值1',color:'#2fc25b'},{text:'自定义2:值2',color:'#facc14'},
                  {text:'自定义3:值3',color:'#f04864'}]; //下面是event的模拟,tooltip的Y坐标值通过这个mp.changedTouches[0].y控制 let tmpevent={mp:{changedTouches:[{x: 0, y: 80}]}}; setTimeout(()=>{ canvaLineA.showToolTip( tmpevent , { index:cindex, textList:textList }); },200) }, touchLineA(e) { canvaLineA.touchLegend(e); canvaLineA.showToolTip(e, { format: function (item, category) { return category + ' ' + item.name + ':' + item.data } }); }, } } </script> <style lang="scss" scoped> .qiun-charts{ width: 750upx; height:500upx; background-color: #FFFFFF; } .charts{ width: 750upx; height:500upx; background-color: #FFFFFF; } </style>

touchLegend(e) 图例点击交互事件

showToolTip(e) 图表中展示数据详细内容

 legend中的两个属性position和float来修改标题的位置:

legend:{
                        show:true,
                        padding:5,
                        lineHeight:11,
                        margin:0,
                        position: 'top',
                        float: 'right'
                    },

dataLabel属性用来修改曲线上是否显示数组,值为true表示显示数据,值为false表示隐藏数据

dataPointShape属性用来控制曲线上是否显示点。值为true表示显示点,值为false表示隐藏点

xAxis.labelCount:默认series.data.length,X轴可见区域标签数量(即X轴数刻度标签单屏幕限制显示的数量)

boundaryGap:折线图、区域图起画点结束点方法:center为单元格中间起画,justify为0点起画即两端对齐

当值为justify时是这样的:

 

 当值为justify时是这样的:

 

 toFixed() 方法可把 Number 四舍五入为指定小数位数的数字。toFixed(0)表示小数位数为0.

 

posted on 2021-03-26 10:29  周文豪  阅读(16417)  评论(1编辑  收藏  举报