我已经实现了一个启动画面，当我的应用程序在启动时从远程云存储加载数据库时显示。通过调用.update（），启动屏幕保持活动状态（其上有一个进度条），并在单独的加载过程结束后销毁。在此之后，主循环启动并且应用程序正常运行。
以下代码用于在我的Mac上使用python 3.6和tcl / tk 8.5.9正常工作。但是，在更新到Sierra之后，我被迫将tk更新为ActiveTcl 8.5.18。现在，在单独的进程完成之前不会显示启动画面，但随后会出现并与根窗口一起停留在屏幕上（即使调用了.destroy（）方法）。
import tkinter as tk
import tkinter.ttk as ttk
import multiprocessing
import time
class SplashScreen(tk.Toplevel):
def __init__(self, root):
tk.Toplevel.__init__(self, root)
self.geometry('375x375')
self.overrideredirect(True)
self.columnconfigure(0, weight=1)
self.rowconfigure(0, weight=1)
self.label = ttk.Label(self, text='My Splashscreen', anchor='center')
self.label.grid(column=0, row=0, sticky='nswe')
self.center_splash_screen()
print('initialized splash')
def center_splash_screen(self):
w = self.winfo_screenwidth()
h = self.winfo_screenheight()
x = w / 2 - 375 / 2
y = h / 2 - 375 / 2
self.geometry("%dx%d+%d+%d" % ((375, 375) + (x, y)))
def destroy_splash_screen(self):
self.destroy()
print('destroyed splash')
class App(tk.Tk):
def __init__(self):
tk.Tk.__init__(self)
self.start_up_app()
self.title("MyApp")
self.columnconfigure(0, weight=1)
self.rowconfigure(0, weight=1)
self.application_frame = ttk.Label(self, text='Rest of my app here', anchor='center')
self.application_frame.grid(column=0, row=0, sticky='nswe')
self.mainloop()
def start_up_app(self):
self.show_splash_screen()
# load db in separate process
process_startup = multiprocessing.Process(target=App.startup_process)
process_startup.start()
while process_startup.is_alive():
# print('updating')
self.splash.update()
self.remove_splash_screen()
def show_splash_screen(self):
self.withdraw()
self.splash = SplashScreen(self)
@staticmethod
def startup_process():
# simulate delay while implementation is loading db
time.sleep(5)
def remove_splash_screen(self):
self.splash.destroy_splash_screen()
del self.splash
self.deiconify()
if __name__ == '__main__':
App()
我不明白为什么会这样，以及如何解决它。有人可以帮忙吗？谢谢！
如果您取消注释行self.overrideredirect(True)，则会正确显示启动画面。但是，我不想要窗口装饰，它仍然保留在脚本末尾的屏幕上。它正在被内部销毁，任何进一步的方法调用self.splash（例如.winfo_... - 方法）都会导致_tkinter.TclError: bad window path name ".!splashscreen"。
此外，此代码在windows和tcl / tk 8.6下运行正常。这是Mac上tcl / tk 8.5.18窗口管理的错误/问题吗？
答案 0 :(得分：0)
显然，这是由于在调用overrideredirect(True)后窗口管理器没有装饰窗口时窗口堆叠顺序出现问题。它似乎也出现在其他平台上。
使用Python 3.6.1和tcl / tk 8.5.18在macOS 10.12.5上运行以下代码，在按钮“打开”后不显示顶层窗口。点击：
import tkinter as tk
class TL(tk.Toplevel):
def __init__(self):
tk.Toplevel.__init__(self)
self.overrideredirect(True)
# self.after_idle(self.lift)
tl_label = tk.Label(self, text='this is a undecorated\ntoplevel window')
tl_label.grid(row=0)
b_close = tk.Button(self, text='close', command=self.close)
b_close.grid(row=1)
def close(self):
self.destroy()
def open():
TL()
root = tk.Tk()
label = tk.Label(root, text='This is the root')
label.grid(row=0)
b_open = tk.Button(root, text='open', command=open)
b_open.grid(row=1)
root.mainloop()
取消注释行self.after_idle(self.lift)可以解决问题（只需调用self.lift()也可以。但是使用after_idle()会阻止窗口在移动到其之前闪烁几分之一秒位置和调整大小，这是我经常与tkinter经历的另一个问题，让我想知道我是否应该继续学习PyQT或PySide2 ......）。
关于在原始问题中关闭未修饰窗口的问题：调用after_idle（window.destroy（））而不是window.destroy（）似乎也解决了这个问题。我不明白为什么。
如果其他人重现这一点，并且有人暗示我将这个报告为错误，我很乐意这样做。
答案 1 :(得分：0)
我在寻找有关如何制作不依赖于时间的 tkinter 启动画面的示例时遇到了这个问题（大多数其他示例都是如此）。 Sam 的版本按原样对我有用。我决定让它成为一个可扩展的独立类来处理所有逻辑，这样它就可以直接放入现有程序中：
# Original Stackoverflow thread:
# https://stackoverflow.com/questions/44802456/tkinter-splash-screen-multiprocessing-outside-of-mainloop
import multiprocessing
import tkinter as tk
import functools
class SplashScreen(tk.Toplevel):
def __init__(self, root, **kwargs):
tk.Toplevel.__init__(self, root, **kwargs)
self.root = root
self.elements = {}
root.withdraw()
self.overrideredirect(True)
self.columnconfigure(0, weight=1)
self.rowconfigure(0, weight=1)
# Placeholder Vars that can be updated externally to change the status message
self.init_str = tk.StringVar()
self.init_str.set('Loading...')
self.init_int = tk.IntVar()
self.init_float = tk.DoubleVar()
self.init_bool = tk.BooleanVar()
def _position(self, x=.5,y=.5):
screen_w = self.winfo_screenwidth()
screen_h = self.winfo_screenheight()
splash_w = self.winfo_reqwidth()
splash_h = self.winfo_reqheight()
x_loc = (screen_w*x) - (splash_w/2)
y_loc = (screen_h*y) - (splash_h/2)
self.geometry("%dx%d+%d+%d" % ((splash_w, splash_h) + (x_loc, y_loc)))
def update(self, thread_queue=None):
super().update()
if thread_queue and not thread_queue.empty():
new_item = thread_queue.get_nowait()
if new_item and new_item != self.init_str.get():
self.init_str.set(new_item)
def _set_frame(self, frame_funct, slocx=.5, sloxy=.5, ):
"""
Args:
frame_funct: The function that generates the frame
slocx: loction on the screen of the Splash popup
sloxy:
init_status_var: The variable that is connected to the initialization function that can be updated with statuses etc
Returns:
"""
self._position(x=slocx,y=sloxy)
self.frame = frame_funct(self)
self.frame.grid(column=0, row=0, sticky='nswe')
def _start(self):
for e in self.elements:
if hasattr(self.elements[e],'start'):
self.elements[e].start()
@staticmethod
def show(root, frame_funct, function, callback=None, position=None, **kwargs):
"""
Args:
root: The main class that created this SplashScreen
frame_funct: The function used to define the elements in the SplashScreen
function: The function when returns, causes the SplashScreen to self-destruct
callback: (optional) A function that can be called after the SplashScreen self-destructs
position: (optional) The position on the screen as defined by percent of screen coordinates
(.5,.5) = Center of the screen (50%,50%) This is the default if not provided
**kwargs: (optional) options as defined here: https://www.tutorialspoint.com/python/tk_toplevel.htm
Returns:
If there is a callback function, it returns the result of that. Otherwise None
"""
manager = multiprocessing.Manager()
thread_queue = manager.Queue()
process_startup = multiprocessing.Process(target=functools.partial(function,thread_queue=thread_queue))
process_startup.start()
splash = SplashScreen(root=root, **kwargs)
splash._set_frame(frame_funct=frame_funct)
splash._start()
while process_startup.is_alive():
splash.update(thread_queue)
process_startup.terminate()
SplashScreen.remove_splash_screen(splash, root)
if callback: return callback()
return None
@staticmethod
def remove_splash_screen(splash, root):
splash.destroy()
del splash
root.deiconify()
class Screen(tk.Frame):
# Options screen constructor class
def __init__(self, parent):
tk.Frame.__init__(self, master=parent)
self.grid(column=0, row=0, sticky='nsew')
self.columnconfigure(0, weight=1)
self.rowconfigure(0, weight=1)
### Demo ###
import time
def splash_window_constructor(parent):
"""
Function that takes a parent and returns a frame
"""
screen = SplashScreen.Screen(parent)
label = tk.Label(screen, text='My Splashscreen', anchor='center')
label.grid(column=0, row=0, sticky='nswe')
# Connects to the tk.StringVar so we can updated while the startup process is running
label = tk.Label(screen, textvariable=parent.init_str, anchor='center')
label.grid(column=0, row=1, sticky='nswe')
return screen
def startup_process(thread_queue):
# Just a fun method to simulate loading processes
startup_messages = ["Reticulating Splines","Calculating Llama Trajectory","Setting Universal Physical Constants","Updating [Redacted]","Perturbing Matrices","Gathering Particle Sources"]
r = 10
for n in range(r):
time.sleep(.2)
thread_queue.put_nowait(f"Loading database.{'.'*n}".ljust(27))
time.sleep(1)
for n in startup_messages:
thread_queue.put_nowait(n)
time.sleep(.2)
for n in range(r):
time.sleep(.2)
thread_queue.put_nowait(f"Almost Done.{'.'*n}".ljust(27))
for n in range(r):
time.sleep(.5)
thread_queue.put_nowait("Almost Done..........".ljust(27))
time.sleep(.5)
thread_queue.put_nowait("Almost Done......... ".ljust(27))
def callback(text):
# To be run after the splash screen completes
print(text)
class App(tk.Tk):
def __init__(self):
tk.Tk.__init__(self)
self.callback_return = SplashScreen.show(root=self,
frame_funct=splash_window_constructor,
function=startup_process,
callback=functools.partial(callback,"Callback Done"))
self.title("MyApp")
self.columnconfigure(0, weight=1)
self.rowconfigure(0, weight=1)
self.application_frame = tk.Label(self, text='Rest of my app here', anchor='center')
self.application_frame.grid(column=0, row=0, sticky='nswe')
self.mainloop()
if __name__ == "__main__":
App()