问题描述
我正在尝试制作一个连接到选定串行端口的 Tkinter 应用程序，并将发送和接收的数据显示到文本小部件。我不知道如何在这样的应用程序中处理来自串行端口的数据的不断检查，因为我最初的方法导致应用程序窗口在几秒钟后没有响应。更具体地说，在用户选择一个端口并连接到它之后，我尝试连续运行 2 个函数。一个从串行端口读取任何数据（如果有任何可用）（ receive_data() ），另一个用于使用任何新数据刷新文本小部件（ refresh_comms() ）。非常感谢对此事的任何帮助，也欢迎对整体代码发表评论！这是代码：
import serial
import tkinter as tk
from tkinter import ttk
import time
import threading
class Application(tk.Tk):
rel_entrywidth_y= 0.02
baud_rate_list = [1200,1800,2400,4800,7200,9600,14400,19200]
HEIGHT = 650
WIDTH = 750
def __init__(self):
super().__init__()
self.title("SERIAL COMMUNICATION")
self.default_com = 'COM13'
self.connect_state = "Not Connected"
self.data = []
self.temp = []
self.createWidgets()
def createWidgets(self):
self.canvas = tk.Canvas(self,width=self.WIDTH,height=self.HEIGHT,bg='#adadad')
self.canvas.pack()
self.port_label = tk.Label(self.canvas,text="Select Port:",font="Courier 12",bg = '#adadad')
self.port_label.place(anchor='nw',relx=0.01,rely=self.rel_entrywidth_y,relwidth=0.18,relheight=0.05)
self.port_entry = tk.Entry(self.canvas,text='COM1',bg='#A6CCF0',justify='center')
self.port_entry.insert(0,self.default_com)
self.port_entry.place(anchor='nw',relx=0.21,relheight=0.05)
self.baud_rate_var = tk.StringVar(self.canvas)
self.baud_rate_var.set(self.baud_rate_list[5]) # set default baud rate
self.baud_label = tk.Label(self.canvas,text=" Baud Rate:",bg = '#adadad')
self.baud_label.place(anchor='nw',relx=0.4,relheight=0.05)
self.baud_menu = tk.OptionMenu(self,self.baud_rate_var,*self.baud_rate_list)
self.baud_menu.config(font='Courier 12',bg='#A6CCF0')
self.baud_menu.place(anchor='nw',relx=0.6,relheight=0.05)
self.connect_button = tk.Button(self.canvas,text='Connect',font='Courier 12 bold',command=self.connect_func)
self.connect_button.place(anchor='nw',relx=0.815,relwidth=0.15,relheight=0.05)
self.canvas.create_line(0,60,self.WIDTH,width=1)
#self.canvas.create_line(0,570,WIDTH,width=1)
#self.separator1 = ttk.Separator(self.canvas,orient='horizontal',bg='#adadad')
#self.separator1.place(relx=0,rely=0.5,relwidth=1,relheight=0.5)
self.comm_text = tk.Text(self,width=40,height=10,font='Courier 12',state='disabled')
self.comm_text.place(anchor='n',relx=0.63,rely=0.1,relwidth=0.7,relheight=0.75)
self.comm_vsb = tk.Scrollbar(self,orient='vertical',command=self.comm_text.yview)
self.comm_vsb.place(anchor='n',relx=0.985,rely=0.101,relwidth=0.03,relheight=0.749)
self.send_button = tk.Button(self.canvas,text='Send',command=threading.Thread(target=self.send_data).start())
self.send_button.place(anchor='n',relx=0.9,rely=0.89,relheight=0.07)
self.data_entry = tk.Entry(self.canvas,font="Courier 14",bg='#d1d1d1',justify='left')
self.data_entry.place(anchor='n',relx=0.41,rely=0.875,relwidth=0.8,relheight=0.1)
self.img = tk.PhotoImage(file='serial.png')
self.img = self.img.subsample(9)
self.canvas.create_image(50,500,anchor='nw',image=self.img)
def connect_func(self):
if self.connect_state == "Not Connected":
self.com_port = self.port_entry.get()
self.baud_rate = self.baud_rate_var.get()
self.connect_button['text'] = "Close"
self.update_idletasks() # making sure it changes to "Close"
print("COM PORT IS : ",self.com_port)
print("BAUD RATE IS : ",self.baud_rate)
try:
self.ser = serial.Serial(self.com_port,self.baud_rate)
self.connect_state = "Connected"
print("Connected to",self.com_port,"successfully!")
self.after(500,threading.Thread(target=self.receive_data()).start())
except Exception as e:
print("Error connecting to port "," ... ",e)
self.connect_button['text'] = "Connect"
self.connect_state = "Not Connected"
elif self.connect_state == "Connected":
self.ser.close()
print("Closing serial connection with port",self.com_port)
self.connect_button['text'] = "Connect"
self.connect_state = "Not Connected"
def send_data(self):
if self.connect_state == "Connected":
self.send_data = self.data_entry.get()
self.ser.write(self.send_data.encode())
print("SENDING... : " + self.send_data)
self.data.append(self.send_data)
self.refresh_comms(self.send_data)
else:
print("Connect to a serial port first...")
def refresh_comms(self,d):
#print("temp : ",self.temp)
#print("data : ",d)
if len(self.temp) < len(d): # if data has been added
self.comm_text.configure(state='normal')
self.comm_text.insert('end',d[len(d)-1] + '\n')
self.comm_text.see('end') # scroll text
self.comm_text.configure(state='disabled')
self.update_idletasks()
self.temp.append(d[len(d)-1])
self.update_idletasks()
self.after(500,self.receive_data)
def receive_data(self):
if self.ser.in_waiting:
received = self.ser.readline().decode()
self.data.append(str(self.com_port) + ' : ' + received)
print("I received :",received)
self.update_idletasks()
self.after(500,self.refresh_comms(self.data))
app = Application()
app.resizable(False,False)
app.mainloop()
解决方法
为了回答我自己的问题，在对该主题进行了一些研究之后，我让它起作用了。这做到了：
- 为 receive_data 函数创建一个线程，另一个用于更新 gui，在我连接到串行端口后调用它们。
- 不要让这两个函数相互调用，单独运行。 这是代码的一部分，对于任何对细节感兴趣的人：
连接后在线程中调用这两个函数：
self.thread1 = threading.Thread(target=self.receive_data)
self.thread1.daemon = True
self.thread1.start()
self.thread2 = threading.Thread(target=self.update_gui)
self.thread2.daemon = True
self.thread2.start()
receive_data 函数和 update_gui 函数本身：
def update_gui(self):
while True:
try:
if len(self.temp) < len(self.data) and self.ser != None: # if data has been added
self.comm_text.configure(state='normal')
self.comm_text.insert('end',self.data[len(self.data)-1] + '\n')
self.comm_text.see('end') # scroll text
self.comm_text.configure(state='disabled')
self.temp.append(self.data[len(self.data)-1])
time.sleep(0.2)
except:
pass
def receive_data(self):
while True:
if self.ser != None:
try:
self.received = self.ser.readline().decode().replace('\n','')
self.data.append(str(self.com_port) + ': ' + self.received)
print("I received :",self.received)
except:
pass
time.sleep(0.2)