Vue实现调用PC端摄像头实时拍照

<!-- 打开模态框按钮-->
        <el-form-item label="*照片：" prop="headImage">
          <el-input type="text" v-model="imgSrc" />
            <el-col :span="1.5">
              <el-button
                @click="onTake"
                icon="el-icon-camera"
                size="small">
                拍照上传
              </el-button>
            </el-col>
        </el-form-item>
        <!--拍照后显示图片-->
        <el-form-item label="" prop="imgSrc">
          <img v-if="imgSrc"  :src="imgSrc" style="width: 200px;height: 240px;" />
</el-form-item>

<!--拍照模态框-->
    <el-dialog
      title="拍照上传"
      :visible.sync="visible"
      @close="onCancel"
      width="1065px">
      <div class="box">
        <video id="videoCamera" class="canvas" :width="videoWidth" :height="videoHeight" autoPlay></video>
        <canvas id="canvasCamera" class="canvas" :width="videoWidth" :height="videoHeight"></canvas>
      </div>
      <div slot="footer">
        <el-button
          @click="drawImage"
          icon="el-icon-camera"
          size="small">
          拍照
        </el-button>
        <el-button
          v-if="os"
          @click="getCompetence"
          icon="el-icon-video-camera"
          size="small">
          打开摄像头
        </el-button>
        <el-button
          v-else
          @click="stopNavigator"
          icon="el-icon-switch-button"
          size="small">
          关闭摄像头
        </el-button>
        <el-button
          @click="resetCanvas"
          icon="el-icon-refresh"
          size="small">
          重置
        </el-button>
        <el-button
          @click="onCancel"
          icon="el-icon-circle-close"
          size="small">
          完成
        </el-button>
   </div>
</el-dialog>

<script>
export default {
  name: "XXX",
  data() {
    return {
      visible: false,//弹窗
      loading: false,//上传按钮加载
      os: false,//控制摄像头开关
      thisVideo: null,
      thisContext: null,
      thisCancas: null,
      videoWidth: 500,
      videoHeight: 400,
      postOptions:[],
      CertCtl:'',
      // 遮罩层
      loading: true,
      // 选中数组
      ids: [],
      // 非单个禁用
      single: true,
      // 非多个禁用
      multiple: true,
      // 总条数
      total: 0,
      // 项目人员表格数据
      akworkerList: [],
      //工种类别数据字典
      workerTypeOptions:[],
      // 弹出层标题
      title: "",
      // 是否显示弹出层
      open: false,
      // 查询参数
      queryParams: {
        pageNum: 1,
        pageSize: 10,
        imgSrc:undefined,
      },
      // 表单参数
      form: {},
      // 表单校验
      rules: {
      }
    };
  },
  created() {
  },
  methods: {
    /*调用摄像头拍照开始*/
    onTake() {
      this.visible = true;
      this.getCompetence();
    },
    onCancel() {
      this.visible = false;
     /* this.resetCanvas();*/
      this.stopNavigator();
    },
    // 调用摄像头权限
    getCompetence() {
      //必须在model中render后才可获取到dom节点,直接获取无法获取到model中的dom节点
      this.$nextTick(() => {
        const _this = this;
        this.os = false;//切换成关闭摄像头
        this.thisCancas = document.getElementById('canvasCamera');
        this.thisContext = this.thisCancas.getContext('2d');
        this.thisVideo = document.getElementById('videoCamera');
        // 旧版本浏览器可能根本不支持mediaDevices，我们首先设置一个空对象
        if (navigator.mediaDevices === undefined) {
          navigator.menavigatordiaDevices = {}
        }
        // 一些浏览器实现了部分mediaDevices，我们不能只分配一个对象
        // 使用getUserMedia，因为它会覆盖现有的属性。
        // 这里，如果缺少getUserMedia属性，就添加它。
        if (navigator.mediaDevices.getUserMedia === undefined) {
          navigator.mediaDevices.getUserMedia = function (constraints) {
            // 首先获取现存的getUserMedia(如果存在)
            let getUserMedia = navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.getUserMedia;
            // 有些浏览器不支持，会返回错误信息
            // 保持接口一致
            if (!getUserMedia) {
              return Promise.reject(new Error('getUserMedia is not implemented in this browser'))
            }
            // 否则，使用Promise将调用包装到旧的navigator.getUserMedia
            return new Promise(function (resolve, reject) {
              getUserMedia.call(navigator, constraints, resolve, reject)
            })
          }
        }
        const constraints = {
          audio: false,
          video: {width: _this.videoWidth, height: _this.videoHeight, transform: 'scaleX(-1)'}
        };
        navigator.mediaDevices.getUserMedia(constraints).then(function (stream) {
          // 旧的浏览器可能没有srcObject
          if ('srcObject' in _this.thisVideo) {
            _this.thisVideo.srcObject = stream
          } else {
            // 避免在新的浏览器中使用它，因为它正在被弃用。
            _this.thisVideo.src = window.URL.createObjectURL(stream)
          }
          _this.thisVideo.onloadedmetadata = function (e) {
            _this.thisVideo.play()
          }
        }).catch(err => {
          this.$notify({
            title: '警告',
            message: '没有开启摄像头权限或浏览器版本不兼容.',
            type: 'warning'
          });
        });
      });
    },
    //绘制图片
    drawImage() {
      // 点击，canvas画图
      this.thisContext.drawImage(this.thisVideo, 0, 0, this.videoWidth, this.videoHeight);
      // 获取图片base64链接
      this.imgSrc = this.thisCancas.toDataURL('image/png');
      /*const imgSrc=this.imgSrc;*/
    },
    //清空画布
    clearCanvas(id) {
      let c = document.getElementById(id);
      let cxt = c.getContext("2d");
      cxt.clearRect(0, 0, c.width, c.height);
    },
    //重置画布
    resetCanvas() {
      this.imgSrc = "";
      this.clearCanvas('canvasCamera');
    },
    //关闭摄像头
    stopNavigator() {
      if (this.thisVideo && this.thisVideo !== null) {
        this.thisVideo.srcObject.getTracks()[0].stop();
        this.os = true;//切换成打开摄像头
      }
    },
  /*调用摄像头拍照结束*/
  }
};
</script>