PyStand
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skywind3000
执行 subprocess.Popen 会重复启动 Qt 主窗口直到内存耗尽
参考过上面的链接，但是上面是 multiprocessing.Process，我这个是 subprocess.Popen
# app.py
from nicegui import ui, app
@app.get("/health")
def health():
return {"status": "ok"}
@ui.page("/")
async def page_index():
ui.label("nicegui 已启动").classes("mx-auto")
if __name__ in {"__main__", "__mp_main__"}:
ui.run(
title="笔记管理系统",
host="localhost",
port=9999,
native=False,
show=False,
reload=False
)
# main.py
import sys
import subprocess
import atexit
from PySide6.QtWidgets import QApplication, QVBoxLayout, QWidget
from PySide6.QtCore import QTimer, QUrl, QObject
from PySide6.QtWebEngineWidgets import QWebEngineView
from PySide6.QtNetwork import QNetworkAccessManager, QNetworkRequest, QNetworkReply
def terminate_process_gracefully(proc, timeout=5):
if proc and proc.poll() is None:
print("Terminating backend process...")
proc.terminate()
try:
proc.wait(timeout=timeout)
except subprocess.TimeoutExpired:
print("Backend did not terminate gracefully; killing it.")
proc.kill()
class MainWindow(QWidget):
def __init__(self, backend_process):
super().__init__()
self.backend_process = backend_process
self.setWindowTitle("笔记管理系统")
layout = QVBoxLayout(self)
self.view = QWebEngineView()
layout.addWidget(self.view)
self.resize(1200, 900)
# 初始化网络管理器
self.network_manager = QNetworkAccessManager(self)
self.network_manager.finished.connect(self.on_health_check_response)
# 显示加载页
self.show_loading_page()
# 开始检查后端
self._retry_count = 0
QTimer.singleShot(100, self.check_backend_ready)
def check_backend_ready(self):
health_url = "http://127.0.0.1:9999/health"
request = QNetworkRequest(QUrl(health_url))
request.setTransferTimeout(1000) # 1秒超时
reply = self.network_manager.get(request)
reply.setProperty("request_type", "health") # 标记类型
def on_health_check_response(self, reply):
req_type = reply.property("request_type")
print(f"Request type: {req_type}")
if reply.error() == QNetworkReply.NetworkError.NoError:
status_code = reply.attribute(QNetworkRequest.Attribute.HttpStatusCodeAttribute)
if status_code == 200:
print("Backend is ready!")
index_url = "http://127.0.0.1:9999/"
self.view.load(QUrl(index_url))
reply.deleteLater()
return
# 请求失败、超时、连接拒绝等
print(f"Health check failed: {reply.errorString()}")
reply.deleteLater()
self._retry_count += 1
if self._retry_count < 20:
QTimer.singleShot(100, self.check_backend_ready)
else:
self.show_error_page()
def show_loading_page(self):
html = """
<html>
<head>
<style>
body {
margin: 0;
padding: 0;
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
background-color: #f5f5f5;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
color: #333;
}
.loading {
text-align: center;
font-size: 24px;
}
.spinner {
border: 4px solid rgba(0, 0, 0, 0.1);
border-left-color: #0078d7;
border-radius: 50%;
width: 40px;
height: 40px;
animation: spin 1s linear infinite;
margin: 0 auto 20px;
}
@keyframes spin {
to { transform: rotate(360deg); }
}
</style>
</head>
<body>
<div class="loading">
<div class="spinner"></div>
<p>正在启动后端服务，请稍候...</p>
</div>
</body>
</html>
"""
self.view.setHtml(html)
def show_error_page(self):
html = """
<html>
<head>
<style>
body {
margin: 0;
padding: 0;
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
background-color: #fff5f5;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
color: #c00;
}
.error {
text-align: center;
font-size: 20px;
max-width: 600px;
padding: 20px;
}
</style>
</head>
<body>
<div class="error">
<h2>❌ 无法连接到后端服务</h2>
<p>后端进程未能及时启动。请检查日志或手动重启应用。</p>
</div>
</body>
</html>
"""
self.view.setHtml(html)
print("Backend did not start in time.")
def start_backend():
cmd = [sys.executable, "app.py"]
return subprocess.Popen(cmd, cwd=".")
def main():
app = QApplication(sys.argv)
backend_proc = start_backend()
atexit.register(lambda: terminate_process_gracefully(backend_proc, timeout=3))
window = MainWindow(backend_proc)
window.show()
sys.exit(app.exec())
if __name__ == "__main__":
main()
哦，我懂了，subprocess.Popen([sys.executable, "app.py"]) 的 sys.executable 实际指向的是 pystand.exe，所以才会出现重复启动 Qt 主窗口的情况。subprocess.Popen 应该用 runtime/python.exe。
只不过这样的话，runtime 目录中的 python312._pth 得改成这样：
python312.zip
.
../site-packages
# Uncomment to run site.main() automatically
import site
不然找不到第三方库
只不过这样的话，runtime 目录中的 python312._pth 得改成这样：
python312.zip . ../site-packages
Uncomment to run site.main() automatically
import site 不然找不到第三方库
用pythonw就行了呀
