摘要：
FastAPI WebSocket 简单演示 FastAPI WebSocket是一个简单的演示。我下午看到了WebSocket。我觉得很有趣。这比编写CRUD更有趣。正式文件https://fastapi.tiangolo.com/advanced/websockets/效果WebSocket服务使用Python FastAPI框架官方网站demofromtypengimportListfromfastapiimportFastAPI，WebSocket，WebSocketDisconnectapp=FastAPI（）classConnectionManager:def__init__:#存储活动的ws连接对象self.active_connections:List[WebSocket]=[]asyncdefconnect:#等待连接激活ws。accept（）#存储ws连接对象自身。active_连接。appenddefdisconnect：#关闭时删除ws对象self.active_connections.remove@staticmethodasyncdefsend_personal_message：#发送个人消息awaitws.Send _ Textasyncdefbroadcast：#连接自身的广播消息。active_ connections:awaitconnection.send _ textmanager=ConnectionManager（）@app.websocketasyncdefwebsocket _ endpoint：awaitmanager.connectawaitmanager。broadcasttry：whileTrue：data=awaitwebsocket.receive _ text（）awaitmanager.send _ personal _ messageawaitmanager.broadcastexceptWebSocketDisconnect:manager.disconnectawaitmanager.broadcastif__ name __=“__main__”：Importuvicorn#官方建议使用命令启动uvicornmain:app--host=127.0.0.1--port=8010--reloaduvicorn。run前端的前端只是一个简单的演示，并不验证连接。
下午没事看了看WebSocket，感觉这个挺好玩的，比写CRUD有意思。就复制了官网的demo演示看了看。
官方文档https://fastapi.tiangolo.com/advanced/websockets/
效果
WebSocket 服务
使用Python FastAPI框架官网demo
from typing import List
from fastapi import FastAPI, WebSocket, WebSocketDisconnect
app = FastAPI()
class ConnectionManager:
def __init__(self):
# 存放激活的ws连接对象
self.active_connections: List[WebSocket] = []
async def connect(self, ws: WebSocket):
# 等待连接
await ws.accept()
# 存储ws连接对象
self.active_connections.append(ws)
def disconnect(self, ws: WebSocket):
# 关闭时 移除ws对象
self.active_connections.remove(ws)
@staticmethod
async def send_personal_message(message: str, ws: WebSocket):
# 发送个人消息
await ws.send_text(message)
async def broadcast(self, message: str):
# 广播消息
for connection in self.active_connections:
await connection.send_text(message)
manager = ConnectionManager()
@app.websocket("/ws/{user}")
async def websocket_endpoint(websocket: WebSocket, user: str):
await manager.connect(websocket)
await manager.broadcast(f"用户{user}进入聊天室")
try:
while True:
data = await websocket.receive_text()
await manager.send_personal_message(f"你说了: {data}", websocket)
await manager.broadcast(f"用户:{user} 说: {data}")
except WebSocketDisconnect:
manager.disconnect(websocket)
await manager.broadcast(f"用户-{user}-离开")
if __name__ == "__main__":
import uvicorn
# 官方推荐是用命令后启动 uvicorn main:app --host=127.0.0.1 --port=8010 --reload
uvicorn.run(app='main:app', host="127.0.0.1", port=8010, reload=True, debug=True)
前端
前端只是简单使用演示, 没有对连接做鉴权处理。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>聊天1</title>
</head>
<body>
<h1>User1 Chat</h1>
<form action="" onsubmit="sendMessage(event)">
<input type="text" autocomplete="off"/>
<button>Send</button>
</form>
<ul id='messages'>
</ul>
<script>
var ws = new WebSocket("ws://127.0.0.1:8010/ws/user1");
ws.onmessage = function(event) {
var messages = document.getElementById('messages')
var message = document.createElement('li')
var content = document.createTextNode(event.data)
message.appendChild(content)
messages.appendChild(message)
};
function sendMessage(event) {
var input = document.getElementById("messageText")
ws.send(input.value)
input.value = ''
event.preventDefault()
}
</script>
</body>
</html>
用户2， 和上面的用户1没什么区别，只是连接WebSocket 参数变化区分，
其他地方一样，就是url参数变化了。
<script>
var ws = new WebSocket("ws://127.0.0.1:8010/ws/user2");
ws.onmessage = function(event) {
var messages = document.getElementById('messages')
var message = document.createElement('li')
var content = document.createTextNode(event.data)
message.appendChild(content)
messages.appendChild(message)
};
function sendMessage(event) {
var input = document.getElementById("messageText")
ws.send(input.value)
input.value = ''
event.preventDefault()
}
</script>
总结
WebSocket使用还是很简单的，但是封装鉴权，前端断线重连等等操作还是很耗时的。