#过年不停更#HarmonyOS 基于JS封装渐变圆环进度条组件 原创 精华

props: {
    // 圆环宽度
    cWidth: {
      type: Number,
      default: 200,
    },
    // 圆环高度
    cHeight: {
      type: Number,
      default: 200,
    },
    // 缩放级，值越大，越清晰，渲染压力越大
    staticScale:{
      type: Number,
      default: 4,
    },
    // 显示文本
    text: {
      type: String,
      default: '',
    },
    // 圆环宽度
    lineWidth: {
      type: Number,
      default: 20
    },
    // 当前进度
    cRate: {
      type: Number,
      default: 0
    },
    // 进度颜色，当只有一个颜色值时为纯色进度，最多只支持两个颜色，使用半角逗号分开
    cColor: {
      type: String,
      default: '#86C1FF,#2B5BF9'
    },
    // 背景色
    bgColor:{
      type: String,
      default: '#e9ebed'
    },
   // 文字大小 
    textSize: {
      type: Number,
      default: 32
    }
  },
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<element name="khCircle" src="../../../share/component/khCircle/khCircle"></element>
<div class="container">
    <khCircle
      c-width="{{cWidth}}"
      c-weight="{{cHeight}}"
      line-width="{{lineWidth}}"
      c-rate="{{cRate}}"
      static-scale="{{staticScale}}"
      c-color="{{cColor}}"
      bg-color="{{bgColor}}"
      text="{{cRate + '%'}}"
      text-size="40"
    ></khCircle>
</div>
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<canvas id="canvas" class="canvas" ref="canvas"></canvas>
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initCanvas(){
    let canvas = this.$refs.canvas;
    this.ctx = canvas.getContext('2d');
    canvas.width = this.cWidth * this.staticScale;
    canvas.height = this.cHeight * this.staticScale;
  },
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this.ctx.beginPath();
this.ctx.lineCap = "round"; //向线条的每个末端添加圆形线帽
this.ctx.lineWidth = 20;  //绘制圆的边框
this.ctx.strokeStyle = '#ff9800'; //绘制边框的颜色
this.ctx.arc(100,100,100,Math.PI * 1.5,(Math.PI * 1.5 * Math.PI * 2));  
this.ctx.stroke();
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// 将hex表示方式转换为rgb表示方式(这里返回rgb数组模式)
  hexToRgb(sColor){
    var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/;
    sColor = sColor.toLowerCase();
    if(sColor && reg.test(sColor)){
      if(sColor.length === 4){
        var sColorNew = "#";
        for(var i=1; i<4; i+=1){
          sColorNew += sColor.slice(i,i+1).concat(sColor.slice(i,i+1));
        }
        sColor = sColorNew;
      }
      //处理六位的颜色值
      var sColorChange = [];
      for(let i=1; i<7; i+=2){
        sColorChange.push(parseInt("0x"+sColor.slice(i,i+2)));
      }
      return sColorChange;
    }else{
      return sColor;
    }
  },
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/**
   * @description: 封装颜色渐变之间值
   * @param {String} startColor 开始颜色hex
   * @param {Number} endColor 结束颜色hex
   * @param {Number} step 渐变精度
   * @return {Array}
   */
  gradientColor(startColor,endColor,step){
    let startRGB = this.hexToRgb(startColor);//转换为rgb数组模式
    let endRGB = this.hexToRgb(endColor);
    
    let sR = (endRGB[0]-startRGB[0])/step;//总差值
    let sG = (endRGB[1]-startRGB[1])/step;
    let sB = (endRGB[2]-startRGB[2])/step;
    var colorArr = [];
    for(var i=0;i<step;i++){
      //计算每一步的hex值
      var hex = this.rgbToHex('rgb('+parseInt((sR*i+startRGB[0]))+','+parseInt((sG*i+startRGB[1]))+','+parseInt((sB*i+startRGB[2]))+')');
      colorArr.push(hex);
    }
    return colorArr;
  },
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// 将rgb表示方式转换为hex表示方式
  rgbToHex(rgb){
    var _this = rgb;
    var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/;
    if(/^(rgb|RGB)/.test(_this)){
      var aColor = _this.replace(/(?:(|)|rgb|RGB)*/g,"").split(",");
      var strHex = "#";
      for(var i=0; i<aColor.length; i++){
        var hex = Number(aColor[i]).toString(16);
        hex = hex<10 ? 0+''+hex :hex;// 保证每个rgb的值为2位
        if(hex === "0"){
          hex += hex;
        }
        strHex += hex;
      }
      if(strHex.length !== 7){
        strHex = _this;
      }
      return strHex;
    }else if(reg.test(_this)){
      var aNum = _this.replace(/#/,"").split("");
      if(aNum.length === 6){
        return _this;
      }else if(aNum.length === 3){
        var numHex = "#";
        for(let i=0; i<aNum.length; i+=1){
          numHex += (aNum[i]+aNum[i]);
        }
        return numHex;
      }
    }else{
      return _this;
    }
  }
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  /**
   * @description: 圆弧切片绘制
   * @param {Number} percent 圆环展示的进度（0~100
   * @param {String} startColor 开始颜色
   * @param {String} endColor 结束颜色
  */
  paint(percent,startColor,endColor){
    percent = percent / 100;
    !endColor ? endColor = startColor : '';

    // 渐变精度，值越小，渐变越缓和
    const unit = 0.01;

    let division = parseInt((Math.PI * 2)/unit);
    // 生成渐变色数组
    let gradient = this.gradientColor(startColor,endColor,division);
    let arr = gradient.slice(this.num, parseInt(percent*gradient.length));
    this.num = parseInt(percent*gradient.length);
    for(let i=0; i < arr.length; i++){
      this.endAngle = this.startAngle+unit;
      this.drawCircle(arr[i],this.startAngle,this.endAngle);
      this.startAngle+=unit;
    }
  },
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<div class="kh-circle">
  <div class="circle-box" style="width: {{cWidth}}px; height: {{cHeight}}px;">
    <canvas id="canvas" class="canvas" ref="canvas"></canvas>
    <text class="text" show="{{text ? true : false}}" style="font-size: {{textSize}}px;">
      {{text}}
    </text>
  </div>
</div>
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.circle-box{
  position: relative;
}
.canvas{
  width: 100%;
  height: 100%;
}
.text{
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%,-50%);
  z-index: 10;
  text-align: center;
}
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