973301d9创建于 2025年1月27日历史提交

使用WebRTC进行Web视频会议

Web组件可以通过W3C标准协议接口拉起摄像头和麦克风，通过onPermissionRequest接口接收权限请求通知，需在配置文件中声明相应的音频权限。

使用摄像头和麦克风功能前请在module.json5中添加音频相关权限，权限的添加方法请参考在配置文件中声明权限。

 // src/main/resources/base/element/string.json
 {
   "name": "reason_for_camera",
   "value": "reason_for_camera"
 },
 {
   "name": "reason_for_microphone",
   "value": "reason_for_microphone"
 }

  // src/main/module.json5
  "requestPermissions":[
    {
      "name" : "ohos.permission.CAMERA",
      "reason": "$string:reason_for_camera",
      "usedScene": {
        "abilities": [
          "EntryAbility"
        ],
        "when":"inuse"
      }
    },
    {
      "name" : "ohos.permission.MICROPHONE",
      "reason": "$string:reason_for_microphone",
      "usedScene": {
        "abilities": [
          "EntryAbility"
        ],
        "when":"inuse"
      }
    }
  ],

通过在JavaScript中调用W3C标准协议接口navigator.mediaDevices.getUserMedia()，该接口用于拉起摄像头和麦克风。constraints参数是一个包含了video和audio两个成员的MediaStreamConstraints对象，用于说明请求的媒体类型。

在下面的示例中，点击前端页面中的开起摄像头按钮再点击onConfirm，打开摄像头和麦克风。

应用侧代码。

// xxx.ets
import { webview } from '@kit.ArkWeb';
import { BusinessError } from '@kit.BasicServicesKit';
import { abilityAccessCtrl } from '@kit.AbilityKit';

@Entry
@Component
struct WebComponent {
  controller: webview.WebviewController = new webview.WebviewController()

  aboutToAppear() {
    // 配置Web开启调试模式
    webview.WebviewController.setWebDebuggingAccess(true);
    // 获取权限请求通知，点击onConfirm按钮后，拉起摄像头和麦克风。
    let atManager = abilityAccessCtrl.createAtManager();
    atManager.requestPermissionsFromUser(getContext(this), ['ohos.permission.CAMERA', 'ohos.permission.MICROPHONE'])
      .then((data) => {
        console.info('data:' + JSON.stringify(data));
        console.info('data permissions:' + data.permissions);
        console.info('data authResults:' + data.authResults);
      }).catch((error: BusinessError) => {
      console.error(`Failed to request permissions from user. Code is ${error.code}, message is ${error.message}`);
    })
  }

  build() {
    Column() {
      Web({ src: $rawfile('index.html'), controller: this.controller })
        .onPermissionRequest((event) => {
          if (event) {
            AlertDialog.show({
              title: 'title',
              message: 'text',
              primaryButton: {
                value: 'deny',
                action: () => {
                  event.request.deny();
                }
              },
              secondaryButton: {
                value: 'onConfirm',
                action: () => {
                  event.request.grant(event.request.getAccessibleResource());
                }
              },
              cancel: () => {
                event.request.deny();
              }
            })
          }
        })
    }
  }
}

前端页面index.html代码。

<!-- index.html -->
<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
</head>
<body>
<video id="video" width="500px" height="500px" autoplay="autoplay"></video>
<canvas id="canvas" width="500px" height="500px"></canvas>
<br>
<input type="button" title="HTML5摄像头" value="开启摄像头" onclick="getMedia()"/>
<script>
  function getMedia()
  {
    let constraints = {
      video: {width: 500, height: 500},
      audio: true
    };
    // 获取video摄像头区域
    let video = document.getElementById("video");
    // 返回的Promise对象
    let promise = navigator.mediaDevices.getUserMedia(constraints);
    // then()异步，调用MediaStream对象作为参数
    promise.then(function (MediaStream) {
      video.srcObject = MediaStream;
      video.play();
    });
  }
</script>
</body>
</html>