Flutter音视频通话插件cometchat_calls_sdk的使用

一、概述

CometChat Calls SDK for Flutter 是一个强大的工具包，开发者可以利用它快速将可靠的、功能齐全的聊天和音视频通话功能集成到现有的或新的应用程序中。它消除了从零开始构建聊天基础设施的复杂性，从而加速开发过程并缩短上市时间。

二、前提条件

• Flutter >=3.10.5
• Dart >=3.0.5
• Android Studio 2022.2
• Android 7.0, API 24 及以上
• Xcode 15
• iOS 12.0

三、开始使用

要设置Flutter SDK并使用CometChat进行聊天和通话功能，您需要按照以下步骤操作：

1. 注册并创建应用

• 在 CometChat Dashboard 注册以创建一个账户。
• 登录后，创建一个新的应用。创建完成后，CometChat会生成一个Auth Key和App ID。请妥善保管这些凭据，因为稍后会用到它们。
• 查看关键概念，了解CometChat的基本组件。
• 参考集成步骤文档，将SDK集成到您的Flutter应用中。

四、完整示例Demo

import 'dart:math';
import 'package:cometchat_calls_sdk/cometchat_calls_sdk.dart';
import 'package:flutter/material.dart';

// 替换为您的App ID和Region
String appId = "YOUR_APP_ID"; 
String region = "YOUR_APP_REGION";

class CometChatCallsDemo extends StatefulWidget {
  const CometChatCallsDemo({Key? key}) : super(key: key);

  [@override](/user/override)
  State<CometChatCallsDemo> createState() => _CometChatCallsDemoState();
}

class _CometChatCallsDemoState extends State<CometChatCallsDemo>
    implements CometChatCallsEventsListener {
  String? sessionId;
  String? generateTokenResult;
  Widget? videoContainer;

  [@override](/user/override)
  void initState() {
    super.initState();
    initCometChatCallsSDK();
  }

  // 1. 初始化CometChatCalls SDK
  initCometChatCallsSDK() {
    CallAppSettings callAppSettings = (CallAppSettingBuilder()
          ..appId = appId
          ..region = region)
        .build();
    CometChatCalls.init(callAppSettings, onSuccess: (String successMessage) {
      debugPrint("Initialization completed successfully: $successMessage");
      generateToken(); // 成功初始化后生成Token
    }, onError: (CometChatCallsException e) {
      debugPrint("Initialization failed with exception: ${e.message}");
    });
  }

  // 2. 生成Token
  Future<void> generateToken() async {
    String? userAuthToken = ""; // 获取用户认证Token的方法：CometChat.getUserAuthToken()
    CometChatCalls.generateToken(generateNewSessionId(), userAuthToken,
        onSuccess: (GenerateToken generateToken) {
      debugPrint("generateToken success: ${generateToken.token}");
      startCall(generateToken.token!); // 生成Token成功后启动通话
    }, onError: (CometChatCallsException e) {
      debugPrint("generateToken Error: $e");
    });
  }

  // 3. 启动通话
  startCall(String generatedToken) async {
    // 可选设置
    MainVideoContainerSetting videoSettings = MainVideoContainerSetting();
    videoSettings.setMainVideoAspectRatio(VideoStreamsMode.ASPECT_RATIO_CONTAIN);
    videoSettings.setNameLabelParams(
        VideoStreamsPosition.POSITION_TOP_LEFT, true, "#000");
    videoSettings.setZoomButtonParams(
        VideoStreamsPosition.POSITION_TOP_RIGHT, true);
    videoSettings.setUserListButtonParams(
        VideoStreamsPosition.POSITION_TOP_RIGHT, true);
    videoSettings.setFullScreenButtonParams(
        VideoStreamsPosition.POSITION_TOP_RIGHT, true);

    // 通话设置构建器
    CallSettings callSettings = (CallSettingsBuilder()
          ..enableDefaultLayout = true
          ..setMainVideoContainerSetting = videoSettings
          ..listener = this)
        .build();

    // 启动通话
    CometChatCalls.startSession(generatedToken, callSettings,
        onSuccess: (Widget? callingWidget) {
      setState(() {
        videoContainer = callingWidget;
      });
    }, onError: (CometChatCallsException e) {
      debugPrint("Error: StartSession: $e");
    });
  }

  // 生成新的会话ID
  String generateNewSessionId() {
    return "${generateRandomString(4)}-${generateRandomString(4)}-${generateRandomString(4)}";
  }

  // 随机字符串生成器
  String generateRandomString(int len) {
    var r = Random();
    const chars = 'AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz';
    return List.generate(len, (index) => chars[r.nextInt(chars.length)]).join();
  }

  // 通话回调方法
  [@override](/user/override)
  void onAudioModeChanged(List<AudioMode> devices) {
    debugPrint("onAudioModeChanged: ${devices.length}");
  }

  [@override](/user/override)
  void onCallEndButtonPressed() {
    debugPrint("onCallEndButtonPressed");
  }

  [@override](/user/override)
  void onCallEnded() {
    debugPrint("onCallEnded");
  }

  [@override](/user/override)
  void onCallSwitchedToVideo(CallSwitchRequestInfo info) {
    debugPrint("onCallSwitchedToVideo: ${info.requestAcceptedBy}");
  }

  [@override](/user/override)
  void onError(CometChatCallsException ce) {
    debugPrint("onError: ${ce.message}");
  }

  [@override](/user/override)
  void onRecordingToggled(RTCRecordingInfo info) {
    debugPrint("onRecordingToggled: ${info.user?.name}");
  }

  [@override](/user/override)
  void onUserJoined(RTCUser user) {
    debugPrint("onUserJoined: ${user.name}");
  }

  [@override](/user/override)
  void onUserLeft(RTCUser user) {
    debugPrint("onUserLeft: ${user.name}");
  }

  [@override](/user/override)
  void onUserListChanged(List<RTCUser> users) {
    debugPrint("onUserListChanged: ${users.length}");
  }

  [@override](/user/override)
  void onUserMuted(RTCMutedUser muteObj) {
    debugPrint("onUserMuted: ${muteObj.mutedBy}");
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xFF333333),
      body: SafeArea(
        child: videoContainer ??
            const Center(
              child: CircularProgressIndicator(
                color: Colors.white,
              ),
            ),
      ),
    );
  }
}