uniapp实现条码扫描 可开闪光灯，原生H5调用，不需要任何sdk。

主要思路

使用QuaggaJs这个库。调用摄像头使用的 navigator.mediaDevices.getUserMedia 这个H5的api。通过 video 和 canvas 把摄像头获取到的数据展现到页面上，同时调用监听Quagga解析。

1. 获取设备摄像头权限,用于后续开启摄像头。
2. 创建video元素显示摄像头画面,和canvas元素用于QuaggaJS进行图像处理和解码。
3. 初始化QuaggaJS,设置解码参数和回调。
4. 开启摄像头,开始扫描循环tick。
5. 在tick中捕获video画面,绘制到canvas上。
6. 将canvas图像数据传入QuaggaJS,进行解码识别。
7. 解码成功后,在回调中处理识别结果。
8. 关闭摄像头和QuaggaJS,释放资源。
9. 通过组件props设置扫描相关参数,如是否高清模式、需要激活的解码器等。

功能预览

兼容说明

需要https环境才能使用，本地测试可以在 manifest.json 中点击源码展示，找到h5 ，添加："devServer" : { "https" : true},并且打开闪光灯只有在安装chrome内核中可以使用，

一、安装QuaggaJs

官网链接 https://serratus.github.io/quaggaJS/#installing
NPM安装

npm install quagga

当然也可以直接引入mainJs文件

二、获取设备摄像头权限

在mounted钩子中,使用uni.request()获取设备权限:

mounted() {
   
   
  uni.request({
   
   
    name: 'camera',
    success: () => {
   
   
      this.openScan() 
    } 
  })
}

三、创建video和canvas元素

video = document.createElement('video')
video.id = 'video'
video.width = 300
video.height = 200

canvas = document.createElement('canvas')  
canvas.id = 'canvas' 
canvas.width = 300   
canvas.height = 200
canvas.style = 'display:none'

canvas2 = document.createElement('canvas') 
canvas2.id = 'canvas2'
canvas2.width = 300    
canvas2.height = 200

四、初始化Quagga并开始扫描

在openScan方法中初始化Quagga,并开始扫描循环tick:

openScan() {
   
   
  this.isScanning = true

  let width = 300 * this.definition
  let height = 200 * this.definition

  Quagga.init(this.config, (err) => {
   
   
    if (err) throw err
    Quagga.start()
    this.tick()
  })
}

五、图像处理和解码

在tick方法中,不断从video中捕获图像,绘制到canvas上,然后使用Quagga对canvas进行解码:

tick() {
   
   
  if (!this.isScanning) return 
  if (this.video.readyState === this.video.HAVE_ENOUGH_DATA) {
   
   
    this.canvas2d.drawImage(video, 0, 0, width, height)
    const inputStream = {
   
   
      size: width * height * 4,
      canvas: this.canvas
    }
    Quagga.decodeSingle(inputStream, result => {
   
    
      // 解码成功后的处理逻辑
    })
  } else {
   
   
    requestAnimationFrame(this.tick)
  }
}

六、关闭摄像头和Quagga

在beforeDestroy钩子中,关闭摄像头和Quagga:

beforeDestroy() {
   
    
  this.isScanning = false
  Quagga.stop()
  if (this.video.srcObject) {
   
   
    this.video.srcObject.getTracks().forEach(track => {
   
   
      track.stop()
    })
  }
}

参数解析

readers是一维码类型，一般使用code_128_reader，可带字母。一些电子产品类别的一维码就是这个编码ean_reader ：商品常用需要更具实际需求填入。数组中可填多个，但是不推荐，因为不同类型中的一维码可能会被其他类型给解码出来，这样会导致解码不正确。具体类型规则如下图：

         props: {
   
   
            continue: {
   
   
                type: Boolean,
                default: false // ,设置自动扫描次数false  一次   true 持续扫描
            },
            exact: {
   
   
                type: String,
                default: 'environment' // environment 后摄像头  user 前摄像头
            },
            definition: {
   
   
                type: Boolean,
                default: false // fasle 正常  true 高清
            },
            readers: {
   
   
                // 一维码类型
                type: Array,
                default: () => ['code_128_reader']
            }
        }

基于上面所诉内容，我这里有现成的组件代码，复制就可以使用！！quaggaJs的文件可以私我，我发给各位。

组件完整代码

<template>
    <view class="canvasBox">
        <view class="box">
            <view class="line"></view>
            <view class="angle"></view>
        </view>
        <view class="box2" v-if="isUseTorch">
            <view class="track" @click="openTrack">
                <svg t="1653920715959" class="icon" viewBox="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' }}
            </view>
        </view>
        <view class="mask1 mask" :style="'height:' + maskHeight + 'px;'"></view>
        <view class="mask2 mask" :style="'width:' + maskWidth + 'px;top:' + maskHeight + 'px'"></view>
        <view class="mask3 mask" :style="'height:' + maskHeight + 'px;'"></view>
        <view class="mask4 mask" :style="'width:' + maskWidth + 'px;top:' + maskHeight + 'px'"></view>
    </view>
</template>
<script>
    import Quagga from './quagga.min.js'
    export default {
    
    
        props: {
    
    
            continue: {
    
    
                type: Boolean,
                default: false // false 监听一次   true 持续监听
            },
            exact: {
    
    
                type: String,
                default: 'environment' // environment 后摄像头  user 前摄像头
            },
            definition: {
    
    
                type: Boolean,
                default: false // fasle 正常  true 高清
            },
            readers: {
    
    
                // 一维码类型
                type: Array,
                default: () => ['code_128_reader']
            }
        },
        data() {
    
    
            return {
    
    
                windowWidth: 0,
                windowHeight: 0,
                video: null,
                canvas2d: null,
                canvasDom: null,
                canvasDom2: null, // 用于画框
                canvas2d2: null,
                canvasWidth: 300,
                canvasHeight: 200,
                maskWidth: 0,
                maskHeight: 0,
                cpu: 1,
                inter: 0,

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

                isParse: false,

                data1: '',
                data2: ''
            }
        },
        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.isParse = true
            this.$nextTick(() => {
    
    
                this.video = document.createElement('video')
                this.video.width = this.windowWidth
                this.video.height = this.windowHeight

                const canvas = document.createElement('canvas')
                this.canvas = canvas
                canvas.id = 'canvas'
                canvas.width = this.canvasWidth
                canvas.height = this.canvasHeight
                canvas.style = 'display:none;'

                // 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;`

                this.canvas2d = canvas.getContext('2d')

                // 创建第二个canvas
                const canvas2 = document.createElement('canvas')
                this.canvas2 = canvas2
                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.cpu = 1 // navigator.hardwareConcurrency || 1
                //    console.log(navigator.hardwareConcurrency )

                this.createMsk()
                setTimeout(() => {
    
    
                    this.openScan()
                }, 500)
            })
        },
        methods: {
    
    
            openScan() {
    
    
                let width = this.transtion(this.windowHeight)
                let height = this.transtion(this.windowWidth)

                const videoParam = {
    
    
                    audio: false,
                    video: {
    
    
                        facingMode: {
    
    
                            exact: this.exact
                        },
                        width,
                        height
                    }
                }

                navigator.mediaDevices
                    .getUserMedia(videoParam)
                    .then(stream => {
    
    
                        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 => {
    
    
                        console.log('设备不支持', err)
                    })
            },
            tick() {
    
    
                if (!this.isParse) return
                try {
    
    
                    if (this.video.readyState === this.video.HAVE_ENOUGH_DATA) {
    
    
                        this.canvas2d.drawImage(
                            this.video,
                            this.transtion(this.maskWidth),
                            this.transtion(this.maskHeight),
                            this.transtion(300),
                            this.transtion(200),
                            0,
                            0,
                            this.canvasWidth,
                            this.canvasHeight
                        )
                        const img = this.canvas.toDataURL('image/jpg')

                        Quagga.decodeSingle({
    
    
                                inputStream: {
    
    
                                    size: 300 * 2
                                },
                                locator: {
    
    
                                    patchSize: 'large',
                                    halfSample: true
                                },
                                numOfWorkers: this.cpu,
                                decoder: {
    
    
                                    readers: this.readers
                                },
                                locate: true,
                                src: img
                            },
                            result => {
    
    
                                this.canvas2d2.clearRect(0, 0, this.canvasWidth, this.canvasHeight)
                                requestAnimationFrame(this.tick)
                                if (!result || !result.codeResult) return

                                if (!this.data1) return (this.data1 = result.codeResult.code)
                                this.data2 = result.codeResult.code
                                console.log(this.data1, '-', this.data2)
                                if (this.data2 !== this.data1) return (this.data1 = '')
                                this.drawLine(result.box, result.line)
                                if (!this.continue) {
    
    
                                    this.closeCamera()
                                }
                                this.$emit('success', result.codeResult.code)
                            }
                        )
                    } else {
    
    
                        requestAnimationFrame(this.tick)
                    }
                } catch (e) {
    
    
                    console.log('出错了');
                    requestAnimationFrame(this.tick)
                }
            },

            drawLine(box, line) {
    
    
                if (!line[0] || !line[0]['x']) return
                this.canvas2d2.beginPath()
                this.canvas2d2.moveTo(line[0]['x'] / 2, line[0]['y'] / 2)
                this.canvas2d2.lineTo(line[1]['x'] / 2, line[1]['y'] / 2)
                this.canvas2d2.lineWidth = 2
                this.canvas2d2.strokeStyle = '#FF3B58'
                this.canvas2d2.stroke()
            },

            createMsk() {
    
    
                this.maskWidth = this.windowWidth / 2 - 150
                this.maskHeight = this.windowHeight / 2 - 100
            },
            closeCamera() {
    
    
                this.isParse = false
                if (this.video.srcObject) {
    
    
                    this.video.srcObject.getTracks().forEach(track => {
    
    
                        track.stop()
                    })
                }
            },

            transtion(number) {
    
    
                return this.definition ? number * 2.6 : number * 1.6
            },

            openTrack() {
    
    
                this.trackStatus = !this.trackStatus
                this.track.applyConstraints({
    
    
                    advanced: [{
    
    
                        torch: this.trackStatus
                    }]
                })
            }
        },
        beforeDestroy() {
    
    
            this.closeCamera()
        }
    }
</script>
<style scoped>
    page {
    
    
        background-color: #333333;
    }

    .canvasBox {
    
    
        width: 100vw;
        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: 300px;
        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;
    }

    .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;
    }

    .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;
    }

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

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

    .mask2 {
    
    
        right: 0;
        height: 200px;
    }

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

    .mask4 {
    
    
        left: 0;
        height: 200px;
    }
</style>

总结

以上就是整个uniapp条码扫描组件的主要逻辑和步骤。如果在理解和使用上有任何疑问,欢迎随时提出。我会提供更详细的解释和指导。欢迎大家交流