python+Tkinter+多线程的实例

目录

• python+Tkinter+多线程
• tkinter与多线程问题
• 总结

python+Tkinter+多线程

界面和多线程一向是编程里比较难的地方，常见的做法一般是界面一个线程，后台新开一个工作线程，这两个线程进行通信，这样可以让界面不至于为响应。

在python中可以利用队列完成整体的架构设计。

直接给大家看代码吧，一个简单实例，非常好的例子。

import Tkinter,time,threading,random,Queue
class GuiPart():
    def __init__(self,master,queue,endCommand):
        self.queue=queue
        Tkinter.Button(master,text='Done',command=endCommand).pack()
    def processIncoming(self):
        while self.queue.qsize():
            try:
                msg=self.queue.get(0)
                print msg
            except Queue.Empty:
                pass
class ThreadedClient():
    def __init__(self,master):
        self.master=master
        self.queue=Queue.Queue()
        self.gui=GuiPart(master,self.queue,self.endApplication)
        self.running=True
        self.thread1=threading.Thread(target=self.workerThread1)
        self.thread1.start()
        self.periodicCall()
    def periodicCall(self):
        self.master.after(200,self.periodicCall)
        self.gui.processIncoming()
        if not self.running:
            self.master.destroy()
    def workerThread1(self):
        #self.ott=Tkinter.Tk()
        #self.ott.mainloop()
        while self.running:
            time.sleep(rand.random()*1.5)
            msg=rand.random() 
            self.queue.put(msg)
    def endApplication(self):
        self.running=False
rand=random.Random()
root=Tkinter.Tk()
client=ThreadedClient(root)
root.mainloop()

tkinter与多线程问题

长时间执行后台任务，UI会处于无响应状态。在子线程里更新UI状态，听说是不允许的。在哪个线程里调用了tk.mainloop()，就只能在哪个线程里更新UI。

下例演示了如何更新。

import Tkinter as tk
from ttk import *
import time
import Queue, threading
class MainWindow:
    def __init__(self):
        self.root = tk.Tk()
        self.root.title('Demo')
    def show(self):
        self.progress = tk.IntVar()
        self.progress_max = 100
        self.progressbar = Progressbar(self.root, mode='determinate', orient=tk.HORIZONTAL, variable=self.progress, maximum=self.progress_max)
        self.progressbar.pack(fill=tk.BOTH, expand=True, padx=5, pady=5)
        self.progress.set(0)
        btn = tk.Button(self.root, text='start', command=self.start)
        btn.pack(fill=tk.BOTH, expand=True, padx=15, pady=5)
        self.btn = btn
        self.root.mainloop()
    def start(self):
        self.progress.set(0)
        self.btn.config(state=tk.DISABLED)
        self.thread_queue = Queue.Queue() # used to communicate between main thread (UI) and worker thread
        new_thread = threading.Thread(target=self.run_loop, kwargs={'param1':100, 'param2':20})
        new_thread.start()
        # schedule a time-task to check UI
        # it's in main thread, because it's called by self.root
        self.root.after(100, self.listen_for_result)
    def run_loop(self, param1, param2):
        progress = 0
        for entry in range(self.progress_max):
            time.sleep(0.1)
            progress = progress + 1
            self.thread_queue.put(progress)
    def listen_for_result(self):
        '''
        Check if there is something in the queue.
        Must be invoked by self.root to be sure it's running in main thread
        '''
        try:
            progress = self.thread_queue.get(False)
            self.progress.set(progress)
        except Queue.Empty: # must exist to avoid trace-back
            pass
        finally:
            if self.progress.get() < self.progressbar['maximum']:
                self.root.after(100, self.listen_for_result)
            else:
                self.btn.config(state=tk.NORMAL)
if __name__ == '__main__':
    win = MainWindow()
    win.show()

一个进度条。设定最大进度为100。在子线程里每隔0.1秒更新一格。

总结

以上为个人经验，希望能给大家一个参考，也希望大家多多支持自由互联。