快速上手 · uCharts高性能跨端图表

## **引用方法** >[info] import uCharts from '../../components/u-charts/u-charts.js'; > demo文件在uniapp插件市场的下载示例，不同版本（uniapp，原生）的在码云上 ## **模板写法** >[info] < canvas canvas-id="canvasColumn" id="canvasColumn" class="charts"></canvas> ## **样式写法** >[info] .charts{width: 750upx; height:500upx;background-color: #FFFFFF;} ## **实例化方法** >[info] `new uCharts({具体参数详见API参数章节})` ## **注意事项** >[danger] * 传入uCharts的`cWidth`和`cHeight`，要与样式中的width和height相等，否则会造成canvas大小与预期不符。 > * 其他问题详见下章[《常见问题》](https://www.kancloud.cn/qiun/ucharts/content/%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98.md) ## **代码示例** ``` <template> <view class="qiun-columns"> <view class="qiun-bg-white qiun-title-bar qiun-common-mt" > <view class="qiun-title-dot-light">柱状图</view> </view> <view class="qiun-charts">  <canvas canvas-id="canvasColumn" id="canvasColumn" class="charts" :style="{'width':cWidth*pixelRatio+'px','height':cHeight*pixelRatio+'px', 'transform': 'scale('+(1/pixelRatio)+')','margin-left':-cWidth*(pixelRatio-1)/2+'px','margin-top':-cHeight*(pixelRatio-1)/2+'px'}"></canvas>   <canvas canvas-id="canvasColumn" id="canvasColumn" class="charts"></canvas>  </view> </view> </template> <script> import uCharts from '../../components/u-charts/u-charts.js'; var _self; var canvaColumn=null; export default { data() { return { cWidth:'', cHeight:'', pixelRatio:1, serverData:'' } }, onLoad() { _self = this; //#ifdef MP-ALIPAY uni.getSystemInfo({ success: function (res) { if(res.pixelRatio>1){ //正常这里给2就行，如果pixelRatio=3性能会降低一点 //_self.pixelRatio =res.pixelRatio; _self.pixelRatio =2; } } }); //#endif this.cWidth=uni.upx2px(750); this.cHeight=uni.upx2px(500); this.getServerData(); }, methods: { getServerData(){ uni.request({ url: 'https://www.easy-mock.com/mock/5cc586b64fc5576cba3d647b/uni-wx-charts/chartsdata2', data:{ }, success: function(res) { console.log(res.data.data) //下面这个根据需要保存后台数据，我是为了模拟更新柱状图，所以存下来了 _self.serverData=res.data.data; let Column={categories:[],series:[]}; //这里我后台返回的是数组，所以用等于，如果您后台返回的是单条数据，需要push进去 Column.categories=res.data.data.Column.categories; //这里的series数据是后台做好的，如果您的数据没有和前面我注释掉的格式一样，请自行拼接数据 Column.series=res.data.data.Column.series; _self.showColumn("canvasColumn",Column); }, fail: () => { console.log("网络错误，小程序端请检查合法域名"); }, }); }, showColumn(canvasId,chartData){ canvaColumn=new uCharts({ $this:_self, canvasId: canvasId, type: 'column', legend:true, fontSize:11, background:'#FFFFFF', pixelRatio:_self.pixelRatio, animation: true, categories: chartData.categories, series: chartData.series, xAxis: { disableGrid:true, }, yAxis: { }, dataLabel: true, width: _self.cWidth*_self.pixelRatio, height: _self.cHeight*_self.pixelRatio, extra: { column: { width: _self.cWidth*_self.pixelRatio*0.45/chartData.categories.length } } }); }, changeData(){ canvaColumn.updateData({ series: _self.serverData.ColumnB.series, categories: _self.serverData.ColumnB.categories }); } } } </script> <style> page{background:#F2F2F2;width: 750upx;overflow-x: hidden;} .qiun-padding{padding:2%; width:96%;} .qiun-wrap{display:flex; flex-wrap:wrap;} .qiun-rows{display:flex; flex-direction:row !important;} .qiun-columns{display:flex; flex-direction:column !important;} .qiun-common-mt{margin-top:10upx;} .qiun-bg-white{background:#FFFFFF;} .qiun-title-bar{width:96%; padding:10upx 2%; flex-wrap:nowrap;} .qiun-title-dot-light{border-left: 10upx solid #0ea391; padding-left: 10upx; font-size: 32upx;color: #000000} /* 通用样式 */ .qiun-charts{width: 750upx; height:500upx;background-color: #FFFFFF;} .charts{width: 750upx; height:500upx;background-color: #FFFFFF;} </style> ``` 友情链接：[因卓诶-爱生活爱分享技术的博客](https://www.yinzhuoei.com)