#鸿蒙通关秘籍#如何在HarmonyOS NEXT中实现WebSocket客户端的基本通信功能

在HarmonyOS NEXT中，实现WebSocket客户端通信，需要按照以下步骤创建和配置应用：

1. 创建Empty Ability项目：启动HarmonyOS IDE，创建一个新的Empty Ability项目。

2. 配置权限：在module.json5文件中添加访问互联网的权限声明：

   "requestPermissions": [
     {
       "name": "ohos.permission.INTERNET"
     }
   ]
   

3. 实现WebSocket客户端功能：在Index.ets文件中，导入WebSocket模块，并编写WebSocket客户端通信逻辑：

   import webSocket from '@ohos.net.webSocket';
   
   let wsSocket = webSocket.createWebSocket();
   
   @Entry
   @Component
   struct Index {
     @State msgHistory: string = '';
     @State sendMsg: string = '';
     @State wsServerUrl: string = "ws://192.168.100.100:8081/websocket";
     @State canConnect: boolean = false;
     @State canSend: boolean = false;
     scroller: Scroller = new Scroller();
     eventHandleBinded:boolean=false;
   
     bindEventHandle() {
       if(this.eventHandleBinded) {
         return;
       }
       wsSocket.on('open', (err, value) => {
         this.msgHistory += "连接打开: status:" + value['status'] + ", message:" + value['message'] + "\r\n";
         this.scroller.scrollEdge(Edge.Bottom);
       });
       wsSocket.on('message', (err, value) => {
         this.msgHistory += "服务端: " + value + "\r\n";
         this.scroller.scrollEdge(Edge.Bottom);
       });
       wsSocket.on('error', (err) => {
         this.msgHistory += "出现异常: " + JSON.stringify(err) + "\r\n";
         this.scroller.scrollEdge(Edge.Bottom);
       });
       this.eventHandleBinded = true;
     }
   
     build() {
       Row() {
         Column() {
           Text("WebSocket通讯示例")
             .fontSize(14)
             .fontWeight(FontWeight.Bold)
             .width('100%')
             .textAlign(TextAlign.Center)
             .padding(10);
   
           Flex({ justifyContent: FlexAlign.Start, alignItems: ItemAlign.Center }) {
             Text("服务端url：").fontSize(12).width(70).flexGrow(0);
             TextInput({ text: this.wsServerUrl }).onChange((value) => { this.wsServerUrl = value; }).width(110).fontSize(11).flexGrow(1);
             Button("连接").onClick(() => { this.connect2Server(); }).width(60).fontSize(14).flexGrow(0);
           }.width('100%').padding(10);
   
           Flex({ justifyContent: FlexAlign.Start, alignItems: ItemAlign.Center }) {
             TextInput({ placeholder: "输入要发送的消息" }).onChange((value) => { this.sendMsg = value; }).width(200).flexGrow(1);
             Button("发送").enabled(this.canSend).width(60).fontSize(14).flexGrow(0).onClick(() => { this.sendMsg2Server(); });
           }.width('100%').padding(10);
   
           Scroll(this.scroller) {
             Text(this.msgHistory).textAlign(TextAlign.Start).padding(10).width('100%').backgroundColor(0xeeeeee);
           }.align(Alignment.Top).backgroundColor(0xeeeeee).height(300).flexGrow(1)
           .scrollable(ScrollDirection.Vertical).scrollBar(BarState.On).scrollBarWidth(20);
         }.width('100%').justifyContent(FlexAlign.Start).height('100%');
       }.height('100%');
     }
   
     sendMsg2Server() {
       wsSocket.send(this.sendMsg + "\r\n")
         .then((value) => { this.msgHistory += "我:" + this.sendMsg + "\r\n"; })
         .catch((e) => { this.msgHistory += '发送失败' + e.message + "\r\n"; });
     }
   
     connect2Server() {
       this.bindEventHandle();
   
       wsSocket.connect(this.wsServerUrl)
         .then((value) => {
           this.msgHistory += 'connect success ' + "\r\n";
           this.canSend = true;
         })
         .catch((e) => {
           this.msgHistory += 'connect fail ' + e.message + "\r\n";
         });
     }
   }
   

4. 运行应用：编译并运行应用，可以选择使用模拟器或真实设备进行测试。连接到WebSocket服务器后，即可发送和接收消息。