`from PySide6 import QtWidgets, QtCore
from vnpy_tts.gateway.tts_gateway import TtsGateway, TtsMdApi

from vnpy_ctp.gateway.ctp_gateway import CtpMdApi

class SimpleWidget(QtWidgets.QWidget):
"""简单图形控件"""

singal = QtCore.Signal(str) # QtCore.Signal

def __init__(self) -> None:
    """构造函数"""
    super().__init__() # 调用Qt对象c++中的构造函数

    self.api = None
    self.gateway_name: str = "CTP"

    self.log_monitor = QtWidgets.QTextEdit()
    self.log_monitor.setReadOnly(True)

    self.subscribe_button = QtWidgets.QPushButton("订阅")
    self.symbol_line = QtWidgets.QLineEdit()
    self.subscribe_button.clicked.connect(self.subscribe_symbol)

    self.singal.connect(self.log_monitor.append)

    # 设置布局组合
    vbox = QtWidgets.QVBoxLayout()
    vbox.addWidget(self.log_monitor)
    vbox.addWidget(self.symbol_line)
    vbox.addWidget(self.subscribe_button)

    self.setLayout(vbox)

def subscribe_symbol(self):
    symbol =self.symbol_line.text()
    self.api.subscribeMarketData(symbol)

class CtpMdApi(TtsMdApi):

class CtpMdApi(CtpMdApi):

def __init__(self, widget) -> None:
    super().__init__(widget)
    self.widget = widget
    self.gateway_name: str = "CTP"

def onFrontConnected(self):
    self.widget.signal.emit("服务器连接成功")
    ctp_req = {
            "UserID":"9643",
            "Password":"123456",
            "BrokerID":"9999"
            }
    self.reqUserLogin(ctp_req, 1)

def onFrontDisconnected(self, reason):
    self.widget.signal.emit("服务器连接断开", reason)

def onRspUserLogin(self, data, error, reqid, last):
    if not error["ErrorID"]:
        self.widget.signal.emit("行情服务器登录成功")
        self.subscribeMarketData("rb2410")
    else:
        self.widget.signal.emit("行情服务器登录失败 {error}")

def onRtnDepthMarketData(self, data):
    self.widget.signal.emit(str(data))

def main():

app = QtWidgets.QApplication()

widget = SimpleWidget()
widget.show()

api = CtpMdApi(widget)
# api = CtpMdApi(widget.log_monitor)
widget.api = api

api.createFtdcMdApi(".")
# api.registerFront("tcp://122.51.136.165:20004")
api.registerFront("tcp://114.80.54.218:41213")
api.init()

app.exec()

if name == "main":
main()

`