【HTML】基于jsQR实现的HTML单页面扫码功能

前言

最近做了一个扫码签到的功能涉及到获取浏览器摄像头并扫码识别的功能。

选择jsQR的原因：

html5-qrcode：使用简单，识别率低，二维码小不可解析

@zxing/library： 识别率优于html5-qrcode，部分安卓模糊无法使用

jsQR：轻量小巧实用简单，识别率高，小型二维码也可解析，可以自动对焦

实现效果

点击扫码功能进入扫码页面

代码实现

完整代码如下，复制即可运行。（已修复重复扫码无法识别问题）

<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta
  name="viewport"
  content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no"
/>
<!-- 引入样式 自己的服务器资源，可自行替换CDN -->
<link rel="stylesheet" href="https://s3.gendome.net/shopify/css/element.css" />
<!-- 引入组件库 -->
<script src="https://s3.gendome.net/shopify/js/vue.js"></script>
<!-- 引入组件库 -->
<script src="https://s3.gendome.net/shopify/js/element.js"></script>
<script src="https://s3.gendome.net/shopify/js/axios.min.js"></script>
<script src="https://s3.gendome.net/activity/js/jsQR.js"></script>
<title></title>
<style>
  body {
    margin: 0;
    position: relative;
  }

  .cz-header {
    width: 100%;
    height: calc(100vw * 520 / 390);
    background-repeat: no-repeat;
    background-position: center center;
    background-size: 100% 100%;
    box-sizing: border-box;
    padding-top: calc(100vw * 130 / 390);
  }
  .cz-header-title {
    font-size: calc(100vw * 30 / 390);
    font-family: Poppins, Poppins;
    font-weight: 600;
    color: #ffffff;
    line-height: calc(100vw * 30 / 390);
    text-align: center;
    padding: 0 calc(100vw * 39 / 390);
  }
  .cz-nav {
    width: 100%;
    height: calc(100vw * 50 / 390);
    text-align: center;
    background-color: #181818;
    overflow: hidden;
  }
  .cz-nav-box {
    overflow-y: scroll;
    display: flex;
    height: 100%;
  }
  .cz-nav-item {
    /* display: inline-block; */
    padding: 0 calc(100vw * 20 / 390);
    font-size: calc(100vw * 12 / 390);
    font-family: Poppins, Poppins;
    font-weight: 600;
    color: #ffffff;
    white-space: nowrap;
    height: 100%;
    line-height: calc(100vw * 50 / 390);
  }
  .cz-nav-box::-webkit-scrollbar {
    display: none;
  }
  .cz-nav-item-act {
    background: linear-gradient(180deg, #0b95ec 0%, #0962cb 100%);
  }
  .cz-b4 {
    width: 100%;
    box-sizing: border-box;
    padding: calc(100vw * 40 / 390) calc(100vw * 20 / 390);
  }
  .cz-b4-title {
    font-size: calc(100vw * 30 / 390);
    font-family: Poppins, Poppins;
    font-weight: 600;
    color: #000000;
    line-height: calc(100vw * 35 / 390);
  }
  .cz-b4-subTxt {
    font-size: calc(100vw * 12 / 390);
    font-family: Poppins, Poppins;
    font-weight: 500;
    color: #212223;
    line-height: calc(100vw * 15 / 390);
    margin-top: calc(100vw * 9 / 390);
    margin-bottom: calc(100vw * 30 / 390);
  }
  .cz-input .el-input__inner {
    width: 100%;
    height: calc(100vw * 60 / 390);
    border-radius: calc(100vw * 9 / 390);
    font-size: calc(100vw * 16 / 390);
  }
  .cz-input .el-form-item__label {
    height: calc(100vw * 60 / 390);
    font-size: calc(100vw * 20 / 390);
    font-weight: bold;
    line-height: calc(100vw * 60 / 390);
  }
  .cz-form-btn {
    height: calc(100vw * 60 / 390);
    background: linear-gradient(180deg, #0b95ec 0%, #0962cb 100%);
    border-radius: calc(100vw * 9 / 390);
    font-size: calc(100vw * 20 / 390);
    font-family: Poppins, Poppins;
    font-weight: 500;
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: calc(100vw * 40 / 390);
  }
  .cz-content {
    width: 100%;
    /* height: calc(100vw * 100 / 390); */
    box-sizing: border-box;
    border: 1px solid #dcdfe6;
    border-radius: calc(100vw * 9 / 390);
    padding: calc(100vw * 20 / 390);
    margin-top: calc(100vw * 40 / 390);
  }
  .cz-content-item {
    margin-bottom: calc(100vw * 10 / 390);
  }
  .cz-mask {
    width: 100vw;
    height: 100vh;
    background: white;
    position: fixed;
    left: 0;
    top: 0;
  }
  .el-icon-close {
    position: absolute;
    top: calc(100vw * 30 / 390);
    right: calc(100vw * 30 / 390);
    z-index: 11;
    color: white;
  }
  .canvasBox {
    width: 100vw;
    height: 100vh;
    position: relative;

    background-image: linear-gradient(
        0deg,
        transparent 24%,
        rgba(32, 255, 77, 0.1) 25%,
        rgba(32, 255, 77, 0.1) 26%,
        transparent 27%,
        transparent 74%,
        rgba(32, 255, 77, 0.1) 75%,
        rgba(32, 255, 77, 0.1) 76%,
        transparent 77%,
        transparent
      ),
      linear-gradient(
        90deg,
        transparent 24%,
        rgba(32, 255, 77, 0.1) 25%,
        rgba(32, 255, 77, 0.1) 26%,
        transparent 27%,
        transparent 74%,
        rgba(32, 255, 77, 0.1) 75%,
        rgba(32, 255, 77, 0.1) 76%,
        transparent 77%,
        transparent
      );
    background-size: 3rem 3rem;
    background-position: -1rem -1rem;
    z-index: 10;
    background-color: #1110;
  }

  .box {
    width: 200px;
    height: 200px;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    overflow: hidden;
    border: 0.1rem solid rgba(0, 255, 51, 0.2);
    z-index: 11;
  }

  .line {
    height: calc(100% - 2px);
    width: 100%;
    background: linear-gradient(180deg, rgba(0, 255, 51, 0) 43%, #00ff33 211%);
    border-bottom: 3px solid #00ff33;
    transform: translateY(-100%);
    animation: radar-beam 2s infinite alternate;
    animation-timing-function: cubic-bezier(0.53, 0, 0.43, 0.99);
    animation-delay: 1.4s;
  }

  .box:after,
  .box:before,
  .angle:after,
  .angle:before {
    content: "";
    display: block;
    position: absolute;
    width: 3vw;
    height: 3vw;
    z-index: 12;
    border: 0.2rem solid transparent;
  }

  .box:after,
  .box:before {
    top: 0;
    border-top-color: #00ff33;
  }

  .angle:after,
  .angle:before {
    bottom: 0;
    border-bottom-color: #00ff33;
  }

  .box:before,
  .angle:before {
    left: 0;
    border-left-color: #00ff33;
  }

  .box:after,
  .angle:after {
    right: 0;
    border-right-color: #00ff33;
  }

  @keyframes radar-beam {
    0% {
      transform: translateY(-100%);
    }

    100% {
      transform: translateY(0);
    }
  }

  .msg {
    text-align: center;
    padding: 20rpx 0;
  }

  .box2 {
    width: 300px;
    height: 200px;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    z-index: 20;
  }

  .track {
    position: absolute;
    bottom: -100px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 20;
    color: #fff;
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .mask {
    position: absolute;
    z-index: 10;
    background-color: rgba(0, 0, 0, 0.55);
  }

  .mask1 {
    top: 0;
    left: 0;
    right: 0;
  }

  .mask2 {
    right: 0;
  }

  .mask3 {
    right: 0;
    left: 0;
    bottom: 0;
  }

  .mask4 {
    left: 0;
  }

  .error {
    color: #fff;
    padding: 40rpx;
    font-size: 24rpx;
    background-color: #333333;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 550rpx;
    border-radius: 20rpx;
  }

  .error .on1 {
    font-size: 30rpx;
  }
</style>
<div id="app">
  <div class="phone">
    <div class="cz-b4">
      <div class="cz-b4-title">CSDN <br />Clock in!</div>
      <div class="cz-b4-subTxt">Persist in creation!</div>

      <div v-on:click="startScan" class="cz-form-btn" v-loading="loading">
        扫码
      </div>
    </div>
  </div>

  <div class="cz-mask" v-if="scanVisible">
    <div class="canvasBox">
      <template v-if="isUse">
        <div class="box">
          <div class="line"></div>
          <div class="angle"></div>
        </div>
        <div class="box2" v-if="isUseTorch">
          <div class="track" @click="openTrack">
            <svg
              t="1653920715959"
              class="icon"
              divBox="0 0 1024 1024"
              version="1.1"
              xmlns="http://www.w3.org/2000/svg"
              p-id="1351"
              width="32"
              height="32"
            >
              <path
                d="M651.353043 550.479503H378.752795L240.862609 364.315031c-3.688944-4.897391-5.660621-10.876025-5.660621-17.045466v-60.040745c0-15.773416 12.847702-28.621118 28.621118-28.621118h502.459627c15.773416 0 28.621118 12.847702 28.621118 28.621118v59.977143c0 6.105839-1.971677 12.084472-5.660621 17.045466l-137.890187 186.228074zM378.752795 598.308571v398.024348c0 15.328199 12.402484 27.667081 27.667081 27.667081h217.266087c15.328199 0 27.667081-12.402484 27.66708-27.667081V598.308571H378.752795z m136.300124 176.942112c-14.564969 0-26.331429-11.76646-26.331428-26.331428v-81.283975c0-14.564969 11.76646-26.331429 26.331428-26.331429 14.564969 0 26.331429 11.76646 26.331429 26.331429v81.283975c0 14.564969-11.76646 26.331429-26.331429 26.331428zM512 222.608696c-17.554286 0-31.801242-14.246957-31.801242-31.801243V31.801242c0-17.554286 14.246957-31.801242 31.801242-31.801242s31.801242 14.246957 31.801242 31.801242v159.006211c0 17.554286-14.246957 31.801242-31.801242 31.801243zM280.932174 205.881242c-9.47677 0-18.889938-4.197764-25.122981-12.275279L158.242981 67.991056a31.864845 31.864845 0 0 1 5.597019-44.648944 31.864845 31.864845 0 0 1 44.648944 5.597018l97.502609 125.551305a31.864845 31.864845 0 0 1-5.597019 44.648944c-5.787826 4.579379-12.656894 6.741863-19.46236 6.741863zM723.987081 205.881242c-6.805466 0-13.674534-2.162484-19.462361-6.678261a31.794882 31.794882 0 0 1-5.597018-44.648944l97.566211-125.551304a31.794882 31.794882 0 0 1 44.648944-5.597019 31.794882 31.794882 0 0 1 5.597019 44.648944l-97.566211 125.551305c-6.360248 8.077516-15.709814 12.27528-25.186584 12.275279z"
                fill="#ffffff"
                p-id="1352"
              ></path>
            </svg>
            {{ trackStatus ? '关闭闪光灯' : '打开闪光灯' }}
          </div>
        </div>

        <div class="mask1 mask" :style="'height:' + maskHeight + 'px;'"></div>
        <div
          class="mask2 mask"
          :style="'width:' + maskWidth + 'px;top:' + maskHeight + 'px;height:' + canvasHeight + 'px'"
        ></div>
        <div class="mask3 mask" :style="'height:' + maskHeight + 'px;'"></div>
        <div
          class="mask4 mask"
          :style="'width:' + maskWidth + 'px;top:' + maskHeight + 'px;height:' + canvasHeight + 'px'"
        ></div>
      </template>
      <template v-else>
        <slot name="error">
          <div class="error">
            <div class="on1">相机权限被拒绝，请尝试如下操作：</div>
            <div>· 刷新页面后重试；</div>
            <div>· 在系统中检测当前App或浏览器的相机权限是否被禁用；</div>
            <div>· 如果依然不能体验，建议在微信中打开链接；</div>
          </div>
        </slot>
      </template>
    </div>
    <i class="el-icon-close" v-on:click="stopScan"></i>
  </div>
</div>

<script>
  new Vue({
    el: "#app",
    data() {
      return {
        continue: false, // false 监听一次   true 持续监听,
        exact: "environment", // environment 后摄像头  user 前摄像头,
        size: "whole", // whole 全屏  balf 半屏,
        definition: false, // fasle 正常  true 高清

        windowWidth: 0,
        windowHeight: 0,
        video: null,
        canvas2d: null,
        canvas2d2: null,
        canvasWidth: 200,
        canvasHeight: 200,
        maskWidth: 0,
        maskHeight: 0,
        inter: 0,

        track: null,
        isUseTorch: false,
        trackStatus: false,

        isParse: false,
        isUse: true,

        scanVisible: false,
        loading: false,
      };
    },
    computed: {},
    mounted() {
      if (origin.indexOf("https") === -1)
        throw "请在 https 环境中使用摄像头组件。";

      this.windowWidth =
        document.documentElement.clientWidth || document.body.clientWidth;
      this.windowHeight =
        document.documentElement.clientHeight || document.body.clientHeight;
      this.windowHeight =
        this.size === "whole" ? this.windowHeight : this.windowHeight / 2;
    },
    destroyed() {
      this.closeCamera();
    },
    methods: {
      // 成功回调
      success(data) {
        this.scanVisible = false;
        this.closeCamera();
        this.$alert(data, "扫码结果", {
          confirmButtonText: "确定",
          callback: (action) => {
            //do things...
          },
        });
      },
      // 失败回调
      error() {
        //do things...
      },
      // 打开扫码
      startScan() {
        this.scanVisible = true;
        this.$nextTick(() => {
          this.isParse = true;
          this.createMsk();
          this.openScan();
        });
      },
      //关闭扫码
      stopScan() {
        this.scanVisible = false;
        this.closeCamera();
      },
      openScan() {
        const width = this.transtion(this.windowHeight);
        const height = this.transtion(this.windowWidth);
        const videoParam = {
          audio: false,
          video: {
            facingMode: { exact: this.exact },
            width,
            height,
          },
        };
        navigator.mediaDevices
          .getUserMedia(videoParam)
          .then((stream) => {
            this.video = document.createElement("video");
            this.video.width = this.windowWidth;
            this.video.height = this.windowHeight;

            const canvas = document.createElement("canvas");
            canvas.id = "canvas";
            canvas.width = this.transtion(this.canvasWidth);
            canvas.height = this.transtion(this.canvasHeight);
            canvas.style = "display:none;";
            //canvas.style = 'position: fixed;top: 0;z-index: 999;left:0'
            this.canvas2d = canvas.getContext("2d");

            // 设置当前宽高 满屏
            const canvasBox = document.querySelector(".canvasBox");
            canvasBox.append(this.video);
            canvasBox.append(canvas);
            canvasBox.style = `width:${this.windowWidth}px;height:${this.windowHeight}px;`;

            // 创建第二个canvas
            const canvas2 = document.createElement("canvas");
            canvas2.id = "canvas2";
            canvas2.width = this.canvasWidth;
            canvas2.height = this.canvasHeight;
            canvas2.style =
              "position: absolute;top: 50%;left: 50%;z-index: 20;transform: translate(-50%, -50%);";
            this.canvas2d2 = canvas2.getContext("2d");
            canvasBox.append(canvas2);

            this.video.srcObject = stream;
            this.video.setAttribute("playsinline", true);
            this.video.play();
            this.tick();

            this.track = stream.getVideoTracks()[0];
            setTimeout(() => {
              this.isUseTorch = this.track.getCapabilities().torch || null;
            }, 500);
          })
          .catch((err) => {
            this.isUse = false;
            // this.$emit("error", err);
            this.error(err);
          });
      },

      closeCamera() {
        this.isParse = false;
        if (this.video && this.video.srcObject) {
          this.video.srcObject.getTracks().forEach((track) => {
            track.stop();
          });
        }
      },

      tick() {
        if (!this.isParse) return;
        if (this.video.readyState === this.video.HAVE_ENOUGH_DATA) {
          this.canvas2d.drawImage(
            this.video,
            this.transtion(this.maskWidth),
            this.transtion(this.maskHeight),
            this.transtion(200),
            this.transtion(200),
            0,
            0,
            this.transtion(this.canvasWidth),
            this.transtion(this.canvasHeight)
          );

          const imageData = this.canvas2d.getImageData(
            0,
            0,
            this.transtion(this.canvasWidth),
            this.transtion(this.canvasHeight)
          );

          const code = jsQR(imageData.data, imageData.width, imageData.height, {
            inversionAttempts: "dontInvert",
          });

          this.canvas2d2.clearRect(0, 0, this.canvasWidth, this.canvasHeight);
          if (code) {
            this.drawLine(
              code.location.topLeftCorner,
              code.location.topRightCorner
            );
            this.drawLine(
              code.location.topRightCorner,
              code.location.bottomRightCorner
            );
            this.drawLine(
              code.location.bottomRightCorner,
              code.location.bottomLeftCorner
            );
            this.drawLine(
              code.location.bottomLeftCorner,
              code.location.topLeftCorner
            );
            if (code.data) {
              this.getData(code.data);
            }
          }
        }
        requestAnimationFrame(this.tick);
      },
      drawLine(begin, end, color = "#FF3B58") {
        this.canvas2d2.beginPath();
        this.canvas2d2.moveTo(
          this.nutranstion(begin.x),
          this.nutranstion(begin.y)
        );
        this.canvas2d2.lineTo(this.nutranstion(end.x), this.nutranstion(end.y));
        this.canvas2d2.lineWidth = 4;
        this.canvas2d2.strokeStyle = color;
        this.canvas2d2.stroke();
      },

      getData(data) {
        // this.$emit("success", data);
        this.success(data);
        if (!this.continue) {
          this.closeCamera();
        }
      },

      openTrack() {
        this.trackStatus = !this.trackStatus;
        this.track.applyConstraints({
          advanced: [{ torch: this.trackStatus }],
        });
      },

      createMsk() {
        this.maskWidth = this.windowWidth / 2 - this.canvasWidth / 2;
        this.maskHeight = this.windowHeight / 2 - this.canvasHeight / 2;
      },

      transtion(number) {
        return this.definition ? number * 2.8 : number * 1.8;
      },
      nutranstion(number) {
        return this.definition ? number / 2.8 : number / 1.8;
      },
    },
  });
</script>

注意： 需要https环境才能使用！！！

结语

完整代码，详细注释，拒绝废话，看官自取，动动小手，留下鼓励～