Question

我正在创建一个Tkinter程序，该程序创建一个画布，根据保存到文本文件的角度显示车辆位置。我遇到的问题是程序只在启动时才读取文本文件，并且不会继续检查。我知道它应该相当简单，但我已经查看了很多网站，但找不到办法。这是我的代码

$ awk '$4==1{$4="NA"} $4==2{$4=$3; $3="NA"} 1' OFS='\t' 1.txt
008     750     16.3763 NA
028     572     NA      -91.1915
031     421     -19.2564        NA
113     265     -5.05956        NA
147     099     38.017  NA
154     161     -4.43984        NA
170     101     28.2171 NA
179     728     NA      -31.2691

Answer 1

使用root.after(miliseconds, function_name)定期运行将再次读取文件并在画布上移动线条的功能。

在代码中我只创建一次行（在车辆之前），然后我只改变行位置。

from Tkinter import *
import math
import time

w = 800
h = 480

# --- functions ---

def update_line():

    deg_angle = open("current_angle.txt")
    deg_angle = deg_angle.read()[:-2]
    deg_angle = float(deg_angle)

    if deg_angle > 90 or deg_angle <-90:
        deg_angle -= 180

    if deg_angle == 90 or deg_angle == -90: # you need 
        centertopx = 0
        centertopy = h / 2
        centerbottomx = w
        centerbottomy = h / 2
    else:    # deg_angle > -90 and deg_angle < 90:

        angle = math.radians(deg_angle)

        #Center Line
        centertopx = (w/2) + ((h/1.5)*math.tan(angle))
        centertopy = 0
        centerbottomx = (w/2) + ((h - (h/1.5))*math.tan(-angle))
        centerbottomy = h

    # move line
    livemap.coords(line, centertopx, centertopy, centerbottomx, centerbottomy)

    # repeat after 200 ms (0.2s)
    root.after(200, update_line)

# --- main ---

root = Tk()
root.geometry("800x480")
root.configure(background='darkgrey')

content = Frame(root,)
livemap = Canvas(root, width=w, height=h)
livemap.create_rectangle(0, 0, w, h, outline="black", width=5, fill="#9E9E9E")

# create line (without angle) before vehicle
line = livemap.create_line(w/2, 0, w/2, h, fill="red", width=4)

#Triangle that represents vehicle
livemap.create_polygon(
    (w/2)-(w*0.04), (h/1.5)+(h*0.1),
    (w/2)+(w*0.04), (h/1.5)+(h*0.1),
    w/2, h/1.5,
    outline="black", fill="darkorange", width=2)

livemap.create_line(w/2, (h/1.5)+(h*0.07), w/2, h/1.5, fill="black", width=2)

livemap.create_polygon(
    (w/2)-(w*0.04), (h/1.5)+(h*0.1),
    (w/2)+(w*0.04), (h/1.5)+(h*0.1),
    w/2, (h/1.5)+(h*0.07),
    outline="black", fill="darkorange", width=2)

livemap.grid(column=0, row=0, columnspan=4, rowspan=4)

# update line first time
update_line()

root.mainloop()

尝试根据文本文件更新Tkinter中的行位置

1 个答案: