步骤 4：发送和接收第一条消息

使用聊天令牌连接到聊天室并发送第一条消息。以下是 JavaScript 示例代码。此外，还提供了 IVS 客户端 SDK：请参阅 Chat SDK: Android Guide、Chat SDK: iOS Guide 和 Chat SDK: JavaScript Guide。

区域服务：以下示例代码是指您的“受支持的选择区域”。Amazon IVS Chat 提供了可用于发出请求的区域端点。对于 Amazon IVS Chat Messaging API，区域端点的一般语法为：

• wss://edge.ivschat.<region-code>.amazonaws.com

例如，美国西部（俄勒冈州）区域的端点为 wss://edge.ivschat.us-west-2.amazonaws.com。有关受支持区域的列表，请参阅《AWS 一般参考》中 Amazon IVS 页面上的 Amazon IVS 聊天功能信息。

/*
1. To connect to a chat room, you need to create a Secure-WebSocket connection
using the client token you created in the previous steps. Use one of the provided 
endpoints in the Chat Messaging API, depending on your AWS region.
*/
const chatClientToken = "GENERATED_CHAT_CLIENT_TOKEN_HERE";
const socket = "wss://edge.ivschat.us-west-2.amazonaws.com"; // Replace “us-west-2” with supported region of choice.
const connection = new WebSocket(socket, chatClientToken);

/*
2. You can send your first message by listening to user input 
in the UI and sending messages to the WebSocket connection.
*/
const payload = {
  "Action": "SEND_MESSAGE",
  "RequestId": "OPTIONAL_ID_YOU_CAN_SPECIFY_TO_TRACK_THE_REQUEST",
  "Content": "text message",
  "Attributes": {
    "CustomMetadata": "test metadata"
  }
}
connection.send(JSON.stringify(payload));

/*
3. To listen to incoming chat messages from this WebSocket connection 
and display them in your UI, you must add some event listeners.
*/
connection.onmessage = (event) => {
  const data = JSON.parse(event.data);
  displayMessages({
    display_name: data.Sender.Attributes.DisplayName,
    message: data.Content,
    timestamp: data.SendTime
  });
}

function displayMessages(message) {
  // Modify this function to display messages in your chat UI however you like.
  console.log(message);
}

/*
4. Delete a chat message by sending the DELETE_MESSAGE action to the WebSocket 
connection. The connected user must have the "DELETE_MESSAGE" permission to 
perform this action.
*/

function deleteMessage(messageId) {
  const deletePayload = {
    "Action": "DELETE_MESSAGE",
    "Reason": "Deleted by moderator",
    "Id": "${messageId}"
  }
  connection.send(deletePayload);
}

恭喜您，一切准备就绪！现在，您已拥有一个简单的聊天应用程序，可以发送或接收消息。