打印经过的时间并通过单击按钮进行重置的计时器

Question

我有一个GUI，用户可以点击一个名为" next set ";这样他们就可以转移到下一个任务。我想添加一个计时器，当他们启动应用程序时就会启动，并运行计时器，直到他们按下"下一个设置"按钮。当点击时，我想打印经过的时间，计时器重新启动，直到他们按下"下一个设置"。按钮一次。我想定时器自动启动时，代码运行。目前，"下一集"按钮有两个动作，一个是检索下一组图像和我试图包括的另一个动作是重置定时器和打印时间流逝。我还只包含了感觉相关的部分代码，因为它很长。

import time
import tkinter as tk
import csv
from pathlib import Path
import PIL.Image
import PIL.ImageDraw
import PIL.ImageTk
MAX_HEIGHT = 500
IMAGES_PATH = Path("Images")
CSV_LABELS_KEY = "New Labels"
CSV_FILE_NAME_KEY = "FolderNum_SeriesNum"
CSV_BOUNDING_BOX_KEY = "correct_flip_bbox"
counter = 0
timer_id = None
class App(tk.Frame):
def __init__(self, master=None):
super().__init__(master)  # python3 style
self.config_paths = ["config 1.yaml", "config 2.yaml", "config 3.yaml"]
self.config_index = 0
self.clickStatus = tk.StringVar()
self.loadedImages = dict()
self.loadedBoxes = dict()  # this dictionary will keep track of all the boxes drawn on the images
self.master.title('Slideshow')
frame = tk.Frame(self)
tk.Button(frame, text="  Next set ", command=lambda:[self.get_next_image_set(), self.reset()]).pack(side=tk.RIGHT)
tk.Button(frame, text="  Exit  ", command=self.destroy).pack(side=tk.RIGHT)
frame.pack(side=tk.TOP, fill=tk.BOTH)
self.canvas = tk.Canvas(self)
self.canvas.pack()
self._load_dataset()
self.reset()
self.start_timer = None
t = time()
t.start()
def start_timer(self, evt=None):
if self._start_timer is not None:
self._start_timer = time.perf_counter()
# global counter
# counter += 1
# label.config(text=str(counter))
# label.after(1000, count)
def reset(self):
if self._start_timer is None:
elapsed_time = time.perf_counter() - self._start_timer
self._start_timer = None
print('Time elapsed (hh:mm:ss.ms) {}'.format(elapsed_time))

def _load_dataset(self):
try:
config_path = self.config_paths[self.config_index]
self.config_index += 1
except IndexError:
return
image_data = loadData(config_path)
# drawing the image on the label
self.image_data = image_data
self.currentIndex = 0
# start from 0th image
self._load_image()
def _load_image(self):
imgName = self.image_data[self.currentIndex]['image_file']
if imgName not in self.loadedImages:
self.im = PIL.Image.open(self.image_data[self.currentIndex]['image_file'])
ratio = MAX_HEIGHT / self.im.height
# ratio divided by existing height -> to get constant amount
height, width = int(self.im.height * ratio), int(self.im.width * ratio)
# calculate the new h and w and then resize next
self.canvas.config(width=width, height=height)
self.im = self.im.resize((width, height))
if self.im.mode == "1":
self.img = PIL.ImageTk.BitmapImage(self.im, foreground="white")
else:
self.img = PIL.ImageTk.PhotoImage(self.im)
imgData = self.loadedImages.setdefault(self.image_data[self.currentIndex]['image_file'], dict())
imgData['image'] = self.img
imgData['shapes'] = self.image_data[self.currentIndex]['shapes']
# for next and previous so it loads the same image adn don't do calculations again
self.img = self.loadedImages[self.image_data[self.currentIndex]['image_file']]['image']
self.canvas.create_image(0, 0, anchor=tk.NW, image=self.img)
self.show_drag_box()
def loadData(fname):
with open(fname, mode='r') as f:
return yaml.load(f.read(), Loader=yaml.SafeLoader)

if __name__ == "__main__":
data = loadData('config 1.yaml')
app = App(data)
app.pack()  # goes here
app.mainloop()

Answer 1

我使用了datetime而不是time，因为减去两个datetime对象将得到包含小时和分钟的输出，而减去两个time对象只会得到秒。但是，这两种方法都可以工作，您可能只需要使用时间进行更多的重新格式化。

读取应用程序启动时的当前时间并存储它。每次你按下按钮，从当前时间减去你存储的时间，这给你你的时间流逝。然后只需存储您的新当前时间，直到下一个按钮按下。下面的代码演示了这一点。

import tkinter as tk
import datetime as dt
class TimeButton(tk.Frame):
def __init__(self, parent):
super().__init__(parent)
# Start timer
self.current_time = dt.datetime.today()
# Button
self.next_set = tk.Button(self, text='Next Set', command = self.clicked)
self.next_set.pack()
def clicked(self):
now = dt.datetime.today()
time_elapsed = now - self.current_time

print(time_elapsed)
self.current_time = now

if __name__ == "__main__":
window = tk.Tk()
button = TimeButton(window)
button.pack()
window.mainloop()