微信小程序雷达图

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手机上测试效果：

主要参考网站：

http://blog.csdn.net/lecepin/article/details/60466711

但是有些地方不适用在小程序上，需要修改以下几点

1，函数的修改；比如将ctx.strokeStyle = mColorPolygon;修改为ctx.setStrokeStyle(mColorPolygon);将ctx.fillStyle = mColorText;修改为ctx.setFillStyle(mColorText);

2，要让雷达图自适应页面大小。需要修改canvas宽高，将宽高设置为屏幕的宽高

var sys = wx.getSystemInfoSync();//获取设备信息

var mW = sys.windowWidth;

var mH = sys.windowHeight;

3，给雷达图加动画

使用setinterval循环修改x.y值进行画图

 that.Interval = setInterval(function () {
 if (precent <= 1) {
 that.drawRegion(ctx);//画数据区域块
 } else {
 clearInterval(that.Interval);
 }
 }, spaceTime);

4.圆形图片

另起一个canvas，使用circleImg方法

整体代码：

wxss文件

.canvasCon{ 
 margin: 0 auto;
 margin-top: 50rpx;
 height: 670rpx;
}

.canvas{
 margin: 0 auto;
 position: absolute;
 left: 50%;
 transform: translateX(-50%);
}

wxml文件

 <view class='canvasCon' bindtap='clickCanvas'>
 <canvas class="canvas" canvas-id="radarcanvas1" disable-scroll="false" style="width:{{canvasW}}rpx; height:{{canvasH}}rpx;" />
 <canvas class="canvas" canvas-id="radarcanvas2" disable-scroll="false" style="width:{{canvasW}}rpx; height:{{canvasH}}rpx;" />
 <canvas class="canvas" canvas-id="radarcanvas3" disable-scroll="false" style="width:{{canvasW}}rpx; height:{{canvasH}}rpx;" />
 <canvas class="canvas" canvas-id="radarcanvas4" disable-scroll="false" style="width:{{canvasW}}rpx; height:{{canvasH}}rpx;" />
 <canvas class="canvas" canvas-id="radarcanvas5" disable-scroll="false" style="width:{{canvasW}}rpx; height:{{canvasH}}rpx;" />
 </view>

js文件

// pages/test/test.js
// start雷达图初始化数据

var sys = wx.getSystemInfoSync();

var windowWidth = sys.windowWidth;

var mW = sys.windowWidth * 0.85;

var mH = sys.windowHeight * 0.85;

var mdData = [['甜美', 30], ['时尚', 20], ['帅气', 20], ['典雅', 30], ['摩登', 40], ['文雅', 50], ['浪漫', 90], ['自然', 50]];//内心

var mdData2 = [['甜美', 70], ['时尚', 20], ['帅气', 90], ['典雅', 10], ['摩登', 40], ['文雅', 50], ['浪漫', 90], ['自然', 20]];//外在

var mData = [];

var mData2 = [];

var mCount = mdData.length; //边数 

var mCenter = ''; //中心点

var mRadius =''; //半径(减去的值用于给绘制的文本留空间)

var mAngle = Math.PI * 2 / mCount; //角度

var mCtx = null;

var mColorPolygon = '#000000'; //多边形颜色

var mColorLines = '#5e5e5e'; //伞骨颜色

var mColorText = '#000000';//文字颜色

var Interval = '';

var lineInterval = '';

var totalTime = 1000;//总执行时间

var spaceTime = 10;//每隔多久执行一次

var speed = spaceTime / totalTime;//每执行一次完成的进度百分比

var precent = 0;//当前完成的进度百分比

var precent2 = 0;

var lineprecent = 0;

var ctx1 = wx.createCanvasContext('radarcanvas1');

var ctx2 = wx.createCanvasContext('radarcanvas2');

var ctx3 = wx.createCanvasContext('radarcanvas3');

var ctx4 = wx.createCanvasContext('radarcanvas4');

var ctx5 = wx.createCanvasContext('radarcanvas5');

var topText = ["帅气", "时尚", "典雅", "甜美", "自然", "浪漫", "文雅", "摩登"];

var allSpaceTime = 50;//线程执行间隔时间
Page({

 /**
 * 页面的初始数据
 */
 data: {
 canvasW: mW * 2,
 canvasH: mH * 1.2,
 },

 /**
 * 生命周期函数--监听页面加载
 */
 onLoad: function (options) {
 var m = [];
 for (var i = 0; i < mCount; i++) {
 m[(i + 6) % mCount] = mdData[i];
 }
 mData = m;//内在

 var m2 = [];
 for (var i = 0; i < mCount; i++) {
 m2[(i + 6) % mCount] = mdData2[i];
 }
 mData2 = m2;//外在
 mCenter = this.rpx(mW); //中心点
 mRadius = mCenter - this.rpx(85); //半径(减去的值用于给绘制的文本留空间)
 },

 /**
 * 生命周期函数--监听页面初次渲染完成
 */
 onReady: function () {
 
 },

 /**
 * 生命周期函数--监听页面显示
 */
 onShow: function () {
 var that = this;
 that.radarcanvas1();//雷达图文字+边框
 that.clickCanvas();//调用画雷达图
 },
 // 单位转换
 rpx: function (param) {

 if (windowWidth == 0) {
 wx.getSystemInfo({
 success: function (res) {
 windowWidth = res.windowWidth;
 }
 });
 }
 return Number((windowWidth / 750 * param).toFixed(2));
 },
 // 绘制多边伞架
 drawPolygon: function (ctx) {
 ctx.save();
 ctx.setStrokeStyle(mColorPolygon);
 var r = mRadius / mCount; //单位半径
 //画8个圈
 for (var i = 0; i < mCount; i++) {
 ctx.beginPath();
 var currR = r * (i + 1); //当前半径
 //画8条边
 for (var j = 0; j < mCount; j++) {
 var x = mCenter + currR * Math.cos(mAngle * j);
 var y = mCenter + currR * Math.sin(mAngle * j);

 ctx.lineTo(x, y);
 }
 ctx.closePath()
 ctx.stroke();
 //ctx.draw(0, 0, 500, 500);
 }
 //ctx.restore();
 },

 //绘制伞骨
 drawLines: function (ctx) {
 ctx.save();
 ctx.beginPath();
 ctx.setStrokeStyle(mColorLines);
 for (var i = 0; i < mCount; i++) {
 var x = mCenter + mRadius * Math.cos(mAngle * i) * lineprecent;
 var y = mCenter + mRadius * Math.sin(mAngle * i) * lineprecent;
 ctx.moveTo(mCenter, mCenter);
 ctx.lineTo(x, y);
 }
 ctx.stroke();
 //ctx.restore();
 //ctx.draw(0, 0, 500, 500);
 var oldPrectet = lineprecent;
 lineprecent = lineprecent + speed;
 if (oldPrectet < 1 && lineprecent > 1) {
 lineprecent = 1;
 }
 },
 //绘制顶点文本
 drawText: function (ctx) {
 ctx.save();
 var fontSize = mCenter / 12 * 1;
 // ctx.font = fontSize + 'px Microsoft Yahei';
 ctx.setFontSize(fontSize);
 ctx.setFillStyle(mColorText);
 for (var i = 0; i < mCount; i++) {
 var x = mCenter + mRadius * Math.cos(mAngle * i);
 var y = mCenter + mRadius * Math.sin(mAngle * i);
 //通过不同的位置，调整文本的显示位置
 if (mAngle * i >= 0 && mAngle * i < Math.PI / 2) {
 ctx.fillText(mData[i][0], x + 15, y + fontSize - 5);
 } else if (mAngle * i == Math.PI / 2) {
 ctx.fillText(mData[i][0], x - 10, y + fontSize + 10);
 } else if (mAngle * i > Math.PI / 2 && mAngle * i <= Math.PI) {
 ctx.fillText(mData[i][0], x - 40, y + fontSize - 10);
 } else if (mAngle * i > Math.PI && mAngle * i <= Math.PI * 3 / 2) {
 ctx.fillText(mData[i][0], x - 15, y - 10);
 } else {
 ctx.fillText(mData[i][0], x, y - 8);
 }
 }
 //ctx.restore();
 //ctx.draw(0, 0, 500, 500);
 },
 //绘制用户圆形头像
 drawPhoto: function (ctx) {
 var that = this;
 ctx.save();
 that.circleImg(ctx, "../images/detail2/detail7.jpg", mCenter - 32, mCenter - 32, 32);
 //ctx5.stroke();
 //ctx5.restore();
 ctx5.draw(0, 0, mW, mH);
 },
 circleImg: function (ctx, img, x, y, r) {
 ctx.save();
 var d = 2 * r;
 var cx = x + r;
 var cy = y + r;
 ctx.beginPath();
 ctx.arc(cx, cy, r, 0, 2 * Math.PI);
 ctx.clip();
 ctx.drawImage(img, x, y, d, d);
 },
 //绘制数据区域 外在
 drawRegion: function (ctx, outColor) {
 ctx.save();
 ctx.beginPath();
 for (var i = 0; i < mCount; i++) {
 var x = mCenter + mRadius * Math.cos(mAngle * i) * mData[i][1] / 100 * precent;
 var y = mCenter + mRadius * Math.sin(mAngle * i) * mData[i][1] / 100 * precent;
 ctx.lineTo(x, y);
 }
 ctx.closePath();
 ctx.save();
 ctx.setFillStyle(outColor);
 ctx.fill();
 ctx.draw(0, 0, 500, 500);
 var oldPrectet = precent;
 precent = precent + speed;
 if (oldPrectet < 1 && precent > 1) {
 precent = 1;
 }
 },
 //绘制数据区域2 内心
 drawRegion2: function (ctx, innerColor) {
 ctx.save();
 ctx.beginPath();
 for (var i = 0; i < mCount; i++) {
 var x = mCenter + mRadius * Math.cos(mAngle * i) * mData2[i][1] / 100 * precent2;
 var y = mCenter + mRadius * Math.sin(mAngle * i) * mData2[i][1] / 100 * precent2;
 ctx.lineTo(x, y);
 }
 ctx.closePath();
 ctx.save();
 ctx.setFillStyle(innerColor);
 ctx.fill();
 ctx.draw(0, 0, 500, 500);
 var oldPrectet = precent2;
 precent2 = precent2 + speed;
 if (oldPrectet < 1 && precent2 > 1) {
 precent2 = 1;
 }
 },

 //画雷达
 clickCanvas: function () {
 var that = this;
 precent = 0;
 precent2 = 0;
 lineprecent = 0;
 clearInterval(that.Interval);
 clearInterval(that.lineInterval);
 ctx1.clearRect(0, 0, mW, mH);
 ctx2.clearRect(0, 0, mW, mH);
 ctx3.clearRect(0, 0, mW, mH);
 ctx4.clearRect(0, 0, mW, mH);
 ctx5.clearRect(0, 0, mW, mH);
 var outColor = "rgba(183, 179, 156, 0.8)";
 var innerColor = "rgba(228,215,182,0.8)";
 that.lineInterval = setInterval(function () {//渐进画伞骨
 if (lineprecent <= 1) {
 that.drawLines(ctx2);
 ctx2.draw(0, 0, 500, 500);
 } else {
 clearInterval(that.lineInterval);
 }
 }, spaceTime - 20);

 setTimeout(function () {//渐进画数据区域块
 that.Interval = setInterval(function () {
 if (precent <= 1) {
 that.drawRegion(ctx3, outColor);
 that.drawRegion2(ctx4, innerColor);
 } else {
 clearInterval(that.Interval);
 }
 }, spaceTime - 20);
 }, 10);
 that.drawPhoto(ctx5);
 console.info("我点击canvas")
 },
 radarcanvas1: function () {
 var that = this;
 const ctx1 = wx.createCanvasContext('radarcanvas1');
 precent = 0;
 lineprecent = 0;
 that.drawPolygon(ctx1);//画伞架
 that.drawText(ctx1);//画文字 
 ctx1.draw(0, 0, 500, 500);
 },
 /**
 * 生命周期函数--监听页面隐藏
 */
 onHide: function () {
 
 },

 /**
 * 生命周期函数--监听页面卸载
 */
 onUnload: function () {
 
 },

 /**
 * 页面相关事件处理函数--监听用户下拉动作
 */
 onPullDownRefresh: function () {
 
 