在Beaglebone上使用Python Tkinter：显示闪烁

Question

下面是在BeagleBone上使用Python和Tkinter在监视器上显示数据的代码。它工作得很好，但显示数据的文本闪烁。有什么想法吗？

#!/usr/bin/python

import alsaaudio as aa
import audioop
import Tkinter as tk
import tkFont
import threading
import Queue

started = False

class Display(object):

    def __init__(self, parent, queue):
        self.parent = parent
        self.queue = queue

        self._geom = '200x200+0+0'
        parent.geometry("{0}x{1}+0+0".format(
            parent.winfo_screenwidth(), parent.winfo_screenheight()))
        parent.overrideredirect(1)

        parent.title('Listen')
        parent.configure(background='#000000')
        parent.displayFont = tkFont.Font(family="Unit-Bold", size=150)
        self.process_queue()

    def process_queue(self):
        try:
            scaled_vol = self.queue.get(0)
            self.print_message(scaled_vol)
        except Queue.Empty:
            pass

        self.parent.after(100, self.process_queue)

    def print_message(self, messageString):
        print 'message', messageString
        self.message = tk.Message(
            self.parent, text=messageString, bg="#000000",
            font=self.parent.displayFont, fg="#777777", justify="c")
        self.message.place(relx=.5, rely=.5, anchor="c")


def setup_audio(queue, stop_event):
    data_in = aa.PCM(aa.PCM_CAPTURE, aa.PCM_NONBLOCK, 'hw:1')
    data_in.setchannels(2)
    data_in.setrate(44100)
    data_in.setformat(aa.PCM_FORMAT_S16_LE)

    data_in.setperiodsize(256)

    while not stop_event.is_set():
        # Read data from device
        l, data = data_in.read()
        if l:
            # catch frame error
            try:
                max_vol = audioop.rms(data, 2)
                scaled_vol = max_vol // 4680
                print scaled_vol

                if scaled_vol <= 3:
                    # Too quiet, ignore
                    continue

                total_vol += scaled_vol / 10.0

                if started and total_vol > 200.0:
                    started = False
                elif started:
                    queue.put(scaled_vol)

            except audioop.error, e:
                if e.message != "not a whole number of frames":
                    raise e


def main():
    root = tk.Tk()
    queue = Queue.Queue()
    window = Display(root, queue)

    stop_event = threading.Event()
    audio_thread = threading.Thread(target=setup_audio,
                                    args=[queue, stop_event])
    audio_thread.start()
    try:
        root.mainloop()
    finally:
        stop_event.set()
        audio_thread.join()
        pass


if __name__ == '__main__':
    main()

显示器是1920 x 1080.它是我必须检查的唯一显示器。

Answer 1

为了完整性，请使用configure()：

#!/usr/bin/python

import alsaaudio as aa
import audioop
import Tkinter as tk
import tkFont
import threading
import Queue

started = False

class Display(object):

    def __init__(self, parent, queue):
        self.parent = parent
        self.queue = queue

        self._geom = '200x200+0+0'
        parent.geometry("{0}x{1}+0+0".format(
            parent.winfo_screenwidth(), parent.winfo_screenheight()))
        parent.overrideredirect(1)

        parent.title('Listen')
        parent.configure(background='#000000')
        parent.displayFont = tkFont.Font(family="Unit-Bold", size=150)
        self.create_message()
        self.process_queue()

    def process_queue(self):
        try:
            scaled_vol = self.queue.get(0)
            self.message.configure(scaled_vol)
        except Queue.Empty:
            pass

        self.parent.after(100, self.process_queue)

    def create_message(self):
        self.message = tk.Message(
            self.parent, text=messageString, bg="#000000",
            font=self.parent.displayFont, fg="#777777", justify="c")
        self.message.place(relx=.5, rely=.5, anchor="c")

def setup_audio(queue, stop_event):
    data_in = aa.PCM(aa.PCM_CAPTURE, aa.PCM_NONBLOCK, 'hw:1')
    data_in.setchannels(2)
    data_in.setrate(44100)
    data_in.setformat(aa.PCM_FORMAT_S16_LE)

    data_in.setperiodsize(256)

    while not stop_event.is_set():
        # Read data from device
        l, data = data_in.read()
        if l:
            # catch frame error
            try:
                max_vol = audioop.rms(data, 2)
                scaled_vol = max_vol // 4680
                print scaled_vol

                if scaled_vol <= 3:
                    # Too quiet, ignore
                    continue

                total_vol += scaled_vol / 10.0

                if started and total_vol > 200.0:
                    started = False
                elif started:
                    queue.put(scaled_vol)

            except audioop.error, e:
                if e.message != "not a whole number of frames":
                    raise e


def main():
    root = tk.Tk()
    queue = Queue.Queue()
    window = Display(root, queue)

    stop_event = threading.Event()
    audio_thread = threading.Thread(target=setup_audio,
                                    args=[queue, stop_event])
    audio_thread.start()
    try:
        root.mainloop()
    finally:
        stop_event.set()
        audio_thread.join()
        pass


if __name__ == '__main__':
    main()