Python在tkinter中发送websocket消息

Question

我无法在python 2.7中的tkinter中发送websocket消息。我目前有一个tkinter和一个websocket客户端运行在一个线程中，所以他们两个循环同时工作，见here。问题是，每当我尝试输入消息并按下发送按钮，我就会得到一个NameError。我正在使用的websocket客户端是here。

这是我的代码：

from Tkinter import * 
from websocket import * 
from threading import * 

master = Tk() 
master.wm_title("Websocket Test") 
minwidth = master.winfo_screenwidth()/4*3 
minheight = master.winfo_screenheight()/4*3 
master.minsize(width=minwidth, height=minheight) 
master.resizable(0,0) 

def sendmsg(): 
    msg = entry.get() 
    ws.send(msg) 
    return 

text = Text(master) 
text.pack(side=TOP, expand=True,fill=BOTH) 
entry = Entry(master) 
entry.pack(side=BOTTOM, expand=True, fill=BOTH) 
button = Button(master, text="SEND", command=sendmsg) 
button.pack(side=BOTTOM, expand=True, fill=BOTH) 

def on_message(ws, message): 
    text.insert(END, "Received: "+message+"\n") 
    print "Received: "+message 
    return 

def on_error(ws, error): 
    text.insert(END, error+"\n") 
    print error 
    return 

def on_close(ws): 
    text.insert(END, "### closed ###\n") 
    print "### closed ###" 
    return 

def on_open(ws): 
    ws.send("hello") 
    ws.send("testing") 
    return 

def connection(): 
    enableTrace(True) 
    ws = WebSocketApp("ws://echo.websocket.org/", on_message = on_message, on_error = on_error, on_close = on_close) 
    ws.on_open = on_open 

    ws.run_forever() 
    return 

t = Thread(target=connection) 
t.start() 

master.mainloop() 

这是错误消息我在空闲状态，每当我试图发送一个消息：

Exception in Tkinter callback 
Traceback (most recent call last): 
    File "C:\Python27\lib\lib-tk\Tkinter.py", line 1486, in __call__ 
    return self.func(*args) 
    File "C:\Users\User\Desktop\thing.py", line 14, in sendmsg 
    ws.send(msg) 
NameError: global name 'ws' is not defined 

我觉得这事做的线程，但我不确定是什么导致了这个问题。 websocket on_open函数使用ws.send（）将消息成功发送到服务器，但sendmsg函数不会。所有的帮助表示赞赏，因为我对线程完全陌生。

Answer 1

那是因为你做

def sendmsg(): 
    msg = entry.get() 
    ws.send(msg) 
    return 

您需要先初始化的WebSocket：

def sendmsg(): 
    ws = WebSocketApp("ws://echo.websocket.org/", on_message = on_message, on_error = on_error, on_close = on_close) 
    msg = entry.get() 
    ws.send(msg) 
    return 

它看起来像你这样做以后创建WS实例，内connection()，你做ws = WebSocketApp("ws://echo.websocket.org/", on_message = on_message, on_error = on_error, on_close = on_close)。在使用ws之前，请确保你已经完成了这个工作，因为那是它被定义的地方。