Vue WebSocket

最近项目在使用websocket，自己研究了下，详细概念性的知识点可以看这里，vue使用websocket可以参考这篇文章，

我这里分享下开发代码，系统理解下使用方法

后面还有一篇文章，是关于websocket的案例的，看这里。

// 初始化websocket
initWebSocket() { 
        const vm = this
        // 创建一个websocket连接
        vm.websocket = new WebSocket(process.env.WEBSOCKET_API)
        // 看下websocket到底是什么  打印见下文
        console.log(vm.websocket) 

        // websocket建立连接时会触发此方法
        vm.websocket.onopen = function() {
          // console.log('websocket onopen')
          vm.isSocket = true
        }
        // 客户端接收服务端数据时触发
        vm.websocket.onmessage = function(evt) {
          const obj = JSON.parse(evt.data)
          console.log('websocket请求回来的数据')
          console.log(obj)
          switch (obj.Command) {
            case '8801':
              vm.fullscreenLoading = false
              if (obj.code === 0) { // 抓拍成功
                vm.photograph = obj.Body.photoUrl
                vm.getRecordInfo()
                vm.$message.success(obj.Msg)
              } else {
                vm.code = 1
                vm.$message.error(obj.Msg)
              }
              break
            case '8300':
              // vm.$alert('发送成功！', '提示', {
              //   confirmButtonText: '确定'
              // })
              vm.$message.success(obj.Msg)
              vm.selectTempId = null
              vm.textSend = ''
              break
            default :
              // vm.$alert('失败！', '提示', {
              //   confirmButtonText: '确定'
              // })
              vm.$message.error(obj.Msg)
              vm.selectTempId = null
              vm.textSend = ''
              vm.photograph = ''
              break
          }
        }
        // 通信发生错误时触发
        vm.websocket.onerror = function() { // 如果请求出错则再次连接
          vm.initWebSocket()
        }
      },
     }

     /**
       * 切换处理页面(点击tab切换页面)
       * @param index
       */
      openPlan(tab, event) {
        if (this.activeCode === '1' || this.activeCode === '2' && !this.isSocket) {
          console.log('------this.activeCode------')
          console.log(this.activeCode)
          this.initWebSocket()
        }

// 控制台输出 websocket
WebSocket {url: "ws://116.62.56.33:6950/", readyState: 0, bufferedAmount: 0, onopen: null, onerror: null, …}
binaryType: "blob"
bufferedAmount: 0
extensions: ""
onclose: null
onerror: ƒ ()
arguments: [Exception: TypeError: 'caller', 'callee', and 'arguments' properties may not be accessed on strict mode functions or the arguments objects for calls to them at Function.invokeGetter (<anonymous>:2:14)]
caller: [Exception: TypeError: 'caller', 'callee', and 'arguments' properties may not be accessed on strict mode functions or the arguments objects for calls to them at Function.invokeGetter (<anonymous>:2:14)]
length: 0
name: ""
prototype: {constructor: ƒ}
__proto__: ƒ ()
[[FunctionLocation]]: AlarmInfo.vue?637e:1046
[[Scopes]]: Scopes[3]
onmessage: ƒ (evt)
arguments: [Exception: TypeError: 'caller', 'callee', and 'arguments' properties may not be accessed on strict mode functions or the arguments objects for calls to them at Function.invokeGetter (<anonymous>:2:14)]
caller: [Exception: TypeError: 'caller', 'callee', and 'arguments' properties may not be accessed on strict mode functions or the arguments objects for calls to them at Function.invokeGetter (<anonymous>:2:14)]
length: 1
name: ""
prototype:
constructor: ƒ (evt)
__proto__: Object
__proto__: ƒ ()
apply: ƒ apply()
arguments: (...)
bind: ƒ bind()
call: ƒ call()
caller: (...)
constructor: ƒ Function()
length: 0
name: ""
toString: ƒ toString()
Symbol(Symbol.hasInstance): ƒ [Symbol.hasInstance]()
get arguments: ƒ ()
set arguments: ƒ ()
get caller: ƒ ()
set caller: ƒ ()
__proto__: Object
[[FunctionLocation]]: <unknown>
[[Scopes]]: Scopes[0]
[[FunctionLocation]]: AlarmInfo.vue?637e:1010
[[Scopes]]: Scopes[3]
onopen: ƒ ()
arguments: (...)
caller: (...)
length: 0
name: ""
prototype: {constructor: ƒ}
__proto__: ƒ ()
[[FunctionLocation]]: AlarmInfo.vue?637e:1006
[[Scopes]]: Scopes[3]
protocol: ""
readyState: 1
url: "ws://116.62.56.33:6950/"
__proto__: WebSocket

<!-- 部分代码   点击图片抓拍，切换tab，可点击拍照-->
<div class="tab-box-header-right">
  <el-button type="primary" 
             @click="camera"  // 拍照按钮，上图中未显示
             size="small" 
             v-loading.fullscreen.lock="fullscreenLoading" 
             element-loading-text="抓拍中,请稍后..." 
             element-loading-spinner="el-icon-loading" 
             element-loading-background="rgba(255, 255, 255, 0)">拍照</el-button>
</div>

// 当前方法在用户点击拍照时调用
camera() {
        if (this.isSocket) {
          this.fullscreenLoading = true
          this.subscribe()
        }
      }

// websocket向服务器发送消息
subscribe() {
        const v = this
        const data = {
          Command: 8801,
          CommandType: 'command',
          Token: getToken(),
          Body: {
            data: {
              vehicleIds: [this.monInfo.vehicleId],
              channelId: this.cameraValue,
              deviceType: this.eqValue
            }
          }
        }
        // console.log('ws请求参数：', data)
        // 判断websocket当前连接状态
        if (this.websocket.readyState === 1) {
          // 发送数据
          this.websocket.send(JSON.stringify(data))
          console.log(data)
          console.log('消息发送成功')
          console.log(v.photograph)
          setTimeout(() => {
            if (v.code !== 1) {
              if (v.photograph !== null && v.photograph !== '') {
                v.fullscreenLoading = false
                v.$message.error('终端响应超时, 请重试!') // 一个弹窗组件
              }
            }
          }, 10000)
        } else {
          console.log('websocket信息发送失败')
        }
      }

// 关闭页面时，关闭websocket连接
destroyed() {
   this.websocket.close()
}