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- uniapp封裝小程序雷達圖組件的完整代碼
view
<canvas id="radar-canvas" class="radar-canvas" type="2d"></canvas>
style
.radar-canvas
width 550rpx
height 550rpx
margin 0 auto
script
<script>
import { toRpx } from "@/utils/common"
const numCount = 5 //元素個(gè)數
const numSlot = 4 //一條線(xiàn)上的總節點(diǎn)數
const mW = toRpx(275) //Canvas的寬度
const mCenter = mW / 2 //中心點(diǎn)
const mAngle = Math.PI * 2 / numCount //角度
const mRadius = mCenter - toRpx(43) //半徑(減去的值用于給繪制的文本留空間)
let canvas = null // canvas
let canvasCtx = null // canvas context
export default {
name: 'RadarChart',
props: {
},
methods: {
// 初始化雷達圖，在組件掛載的時(shí)候執行
initDrawRadar() {
console.log('init')
const query = uni.createSelectorQuery().in(this)
query.select('#radar-canvas').fields({ node: true, size: true }).exec((res) => {
canvas = res[0].node
canvasCtx = canvas.getContext('2d')
const dpr = uni.getSystemInfoSync().pixelRatio
canvas.width = res[0].width * dpr
canvas.height = res[0].height * dpr
canvasCtx.scale(dpr, dpr)
})
},
// 開(kāi)始執行繪制
handleDraw(radarData) {
this.drawEdge()
this.drawLinePoint()
this.drawText(radarData)
this.drawSubText(radarData)
this.drawEdgeDot()
this.drawRegion(radarData, 'rgba(255, 105, 81, 0.4)')
},
// 繪制圓邊
drawEdge() {
canvasCtx.strokeStyle = '#EEEEEE'
for (let i = 0; i < numSlot; i++) {
// 計算半徑
let radius = mRadius / numSlot * (i + 1)
if (i === 3) {
canvasCtx.lineWidth = toRpx(4) // 設置線(xiàn)寬
canvasCtx.beginPath()
canvasCtx.arc(mCenter, mCenter, radius, 0, 2 * Math.PI,) // 開(kāi)始畫(huà)圓
canvasCtx.stroke()
} else {
canvasCtx.lineWidth = toRpx(1)
const space = 60 + 10 * (i+1)
this.drawDashCircle(mCenter, mCenter, radius, space)
}
}
},
// 繪制外邊框圓點(diǎn)
drawEdgeDot(x, y) {
canvasCtx.fillStyle = '#EEEEEF'
canvasCtx.beginPath()
for (let k = 0; k < numCount; k++) {
let x = mCenter + mRadius * Math.cos(mAngle * k - Math.PI / 2)
let y = mCenter + mRadius * Math.sin(mAngle * k - Math.PI / 2)
canvasCtx.arc(x, y, toRpx(5), Math.PI * 2, 0, true)
canvasCtx.closePath()
}
canvasCtx.fill()
},
// 繪制虛線(xiàn)圓
drawDashCircle(x, y, radius, space = 100) {
const gap = 2 * Math.PI / space
canvasCtx.lineCap ='square'
let start = 0; //從原點(diǎn)開(kāi)始畫(huà)
while (start <= 2 * Math.PI) {
let end = start + gap
canvasCtx.beginPath() //開(kāi)始一個(gè)新的路徑
canvasCtx.arc(x, y, radius, start, end, false)
start = gap + end
canvasCtx.stroke() //對當前路徑進(jìn)行描邊
}
},
// 繪制連接點(diǎn)
drawLinePoint() {
canvasCtx.lineWidth = toRpx(1)
canvasCtx.beginPath()
for (let k = 0; k < numCount; k++) {
let x = mCenter + mRadius * Math.cos(mAngle * k - Math.PI / 2)
let y = mCenter + mRadius * Math.sin(mAngle * k - Math.PI / 2)
canvasCtx.moveTo(mCenter, mCenter)
canvasCtx.lineTo(x, y)
}
canvasCtx.stroke()
},
// 繪制文本信息
drawText(mData) {
canvasCtx.fillStyle = '#222325'
canvasCtx.font = `bold ${toRpx(14)}px PingFangSC-Medium, PingFang SC` //設置字體
for (let n = 0; n < numCount; n++) {
let x = mCenter + mRadius * Math.cos(mAngle * n - Math.PI / 2)
let y = mCenter + mRadius * Math.sin(mAngle * n - Math.PI / 2)
//通過(guò)不同的位置，調整文本的顯示位置
const text = mData[n][0]
if (n === 0) {
canvasCtx.fillText(text, x - toRpx(12), y - toRpx(30))
}
if (n === 1) {
canvasCtx.fillText(text, x + toRpx(12), y)
}
if (n === 2) {
canvasCtx.fillText(text, x + toRpx(12), y + toRpx(20))
}
if (n === 3) {
canvasCtx.fillText(text, x - toRpx(36), y + toRpx(20))
}
if (n === 4) {
canvasCtx.fillText(text, x - toRpx(40), y)
}
}
},
// 繪制文本信息
drawSubText(mData) {
canvasCtx.fillStyle = '#8D949B'
canvasCtx.font = `${toRpx(11)}px PingFangSC-Medium, PingFang SC` //設置字體
for (let n = 0; n < numCount; n++) {
const x = mCenter + mRadius * Math.cos(mAngle * n - Math.PI / 2)
const y = mCenter + mRadius * Math.sin(mAngle * n - Math.PI / 2)
//通過(guò)不同的位置，調整文本的顯示位置
const text = `(${mData[n][1]})`
if (n === 0) {
canvasCtx.fillText(text, x - canvasCtx.measureText(text).width / 2, y - toRpx(10))
}
if (n === 1) {
canvasCtx.fillText(text, x + canvasCtx.measureText(text).width, y + toRpx(16))
}
if (n === 2) {
canvasCtx.fillText(text, x + canvasCtx.measureText(text).width - toRpx(4), y + toRpx(40))
}
if (n === 3) {
canvasCtx.fillText(text, x - canvasCtx.measureText(text).width - toRpx(12), y + toRpx(40))
}
if (n === 4) {
canvasCtx.fillText(text, x - canvasCtx.measureText(text).width - toRpx(16), y + toRpx(16))
}
}
},
//繪制紅色數據區域(數據和填充顏色)
drawRegion(mData, color){
canvasCtx.strokeStyle = '#FF6951'
canvasCtx.lineWidth = toRpx(4) // 設置線(xiàn)寬
canvasCtx.beginPath()
for (let m = 0; m < numCount; m++){
let x = mCenter + mRadius * Math.cos(mAngle * m - Math.PI / 2) * mData[m][1] / 100
let y = mCenter + mRadius * Math.sin(mAngle * m - Math.PI / 2) * mData[m][1] / 100
canvasCtx.lineTo(x, y)
}
canvasCtx.closePath()
canvasCtx.fillStyle = color
canvasCtx.fill()
canvasCtx.stroke()
},
},
mounted() {
this.initDrawRadar()
}
}
</script>
要注意的點(diǎn)是，這里是封裝成組件調用，在初始化的時(shí)候，const query = uni.createSelectorQuery().in(this)，要加上in(this)，否則會(huì )報找不到node節點(diǎn)的錯誤信息
export function toRpx(val) {
const res = uni.getSystemInfoSync()
const scaleRate = res.windowWidth / 375
return val * scaleRate
}
在頁(yè)面中調用
<template>
<!--雷達圖-->
<radar-chart :radarData="radarData" ref="radarRef"></radar-chart>
</template>
import RadarChart from './components/radar'
export default {
components: {
RadarChart,
},
data() {
return {
radarData:[["聽(tīng)力", 0], ["口語(yǔ)",0], ["語(yǔ)法",0], ["詞匯",0], ["閱讀",0]],
}
},
methods: {
getData() {
// 請求數據返回后，調用組件方法渲染
this.$refs.radarRef.handleDraw(this.radarData)
}
}
}
到此這篇關(guān)于uniapp封裝小程序雷達圖組件的文章就介紹到這了,更多相關(guān)uniapp封裝小程序雷達圖組件內容請搜索腳本之家以前的文章或繼續瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！
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