I'm doing a school project. I designed a welcome page for it on tkinter and put a button 'ok' which when pressed moves the code forward but the welcome page doesnt close itself once pressed.
i have tried defining another function to close it but that does not work.
welcome = Tk()
okbutton = Button(welcome, text='ok', command=R)
okbutton.pack()
welcome.mainloop()
and the code moves forward but welcome page remains open...Is there a method to resolve this?
Window never closes automatically when you create new window. You have to use welcome.destroy() for this. You can run it in function which creates new window.
import tkinter as tk
def welcome_page():
global welcome
welcome = tk.Tk()
tk.Label(welcome, text='Welcome').pack()
button = tk.Button(welcome, text='OK', command=other_page)
button.pack()
welcome.mainloop()
def other_page():
global welcome
global other
welcome.destroy() # close previous window
other = tk.Tk()
tk.Label(other, text='Other').pack()
button = tk.Button(other, text='OK', command=end)
button.pack()
welcome.mainloop()
def end():
global other
other.destroy() # close previous window
welcome_page()
To perform the two commands call one command inside the other (sounds like it should be towards the end) and assign the first command to the button.
A button can only call a single function, but that single function can do anything you want.
def do_ok():
print("hello!")
welcome.destroy()
welcome = Tk()
okbutton = Button(welcome, text='ok', command=do_ok)
okbutton.pack()
welcome.mainloop()
Related
I am new to tkinter, I am trying to make a button that flashes green and silver until it is pressed, at which point it reverts to silver. I followed the code from this website, flash button example, it seemed to be closest to what I was trying to do.
%reset -f
import tkinter as tk
root = tk.Tk()
def stop_flash():
print('stop_flash')
root.after_cancel(flasher2)
root.after_cancel(flasher1)
button = tk.Button(root, text="Hello", command=stop_flash, background='silver', activebackground='red')
button.pack()
def flash():
button.configure(background = 'green')
flasher1 = root.after(500, lambda: button.configure(background = 'silver'))
flasher2 = root.after(1000, flash)
flasher1 = root.after(500, lambda: button.configure(background = 'silver'))
flasher2 = root.after(1000, flash)
root.mainloop()
I got the button to flash but I don't understand why it won't stop. I have tried making a separate switch button so I would only need to use 1 after() function but it gets even messier. Any help here would be greatly appreciated!!!!!
There have already been several topics on Python/Tkinter, but I did not find an answer in them for the issue described below.
The two Python scripts below are reduced to the bare essentials to keep it simple. The first one is a simple Tkinter window with a button, and the script needs to wait till the button is clicked:
from tkinter import *
windowItem1 = Tk()
windowItem1.title("Item1")
WaitState = IntVar()
def submit():
WaitState.set(1)
print("submitted")
button = Button(windowItem1, text="Submit", command=submit)
button.grid(column=0, row=1)
print("waiting...")
button.wait_variable(WaitState)
print("done waiting.")
windowItem1.mainloop()
This works fine, and we see the printout “done waiting” when the button is clicked.
The second script adds one level: we first have a menu window, and when clicking the select button of the first presented item, we have a new window opening with the same as above. However, when clicking the submit button, I don’t get the “Done waiting”. I’m stuck on the wait_variable.
from tkinter import *
windowMenu = Tk()
windowMenu.title("Menu")
def SelectItem1():
windowItem1 = Tk()
windowItem1.title("Item1")
WaitState = IntVar()
def submit():
WaitState.set(1)
print("submitted")
button = Button(windowItem1, text="Submit", command=submit)
button.grid(column=0, row=1)
print("waiting...")
button.wait_variable(WaitState)
print("done waiting")
lblItem1 = Label(windowMenu, text="Item 1 : ")
lblItem1.grid(column=0, row=0)
btnItem1 = Button(windowMenu, text="Select", command=SelectItem1)
btnItem1.grid(column=1, row=0)
windowMenu.mainloop()
Can you explain it?
Inside your SelectItem1 function, you do windowItem1 = Tk(). You shouldn't use Tk() to initialize multiple windows in your application, the way to think about Tk() is that it creates a specialized tkinter.Toplevel window that is considered to be the main window of your entire application. Creating multiple windows using Tk() means multiple main windows, and each one would need its own mainloop() invokation, which is... yikes.
Try this instead:
windowItem1 = Toplevel()
I created a button that works perfectly (not entire code here) but I want that once you press the 'Save' button, the window disappear. Someone knows how to do it?
root2 = tk.Tk()
root2.geometry('200x100')
save_button = tk.Button(root2)
save_button.configure(text='Save', command=lambda: ask_parameter(ents1))
save_button.pack()
root2.mainloop()
Based on the extremely limited snippet of code in your question: I would suggest it doing by defining a function to call that does something like this:
import tkinter as tk
def ask_and_close(root, ents):
ask_parameter(ents)
root.destroy()
ents1 = "something"
root2 = tk.Tk()
root2.geometry('200x100')
save_button = tk.Button(root2)
save_button.configure(text='Save', command=lambda: ask_and_close(root2, ents1))
save_button.pack()
root2.mainloop()
Note: If you're creating multiple windows, I wouild suggest using tk.Toplevel() instead of calling tk.TK() more than once.
Just use the master.quit() method!
Example Code:
from tkinter import *
class Test:
def __init__(self):
self.master = Tk()
self.button = Button(self.master, text="Push me!", command=self.closeScreen)
self.button.pack()
def closeScreen(self):
# In your case, you need "root2.quit"
self.master.quit()
test = Test()
mainloop()
I would suggest using destroy() method as used here https://docs.python.org/3.8/library/tkinter.html#a-simple-hello-world-program.
One of the easy ways to invoke the destroy method in your code is this;
def ask_parameter_and_destroy(ents1):
ask_parameter(ents1)
root2.destroy()
root2 = tk.Tk()
root2.geometry('200x100')
save_button = tk.Button(root2)
save_button.configure(text='Save', command=lambda: ask_parameter_and_destroy(ents1))
save_button.pack()
root2.mainloop()
You can read about differences between destroy() and previously proposed quit() methods on the following page: What is the difference between root.destroy() and root.quit()?.
If your goal is to create a dialog for saving a file, you might be interested in tkinter.filedialog library, which has ready made dialog boxes for handling file saving.
I want to close two windows at the same time when user click the Start button, the new window will pop-up and when the user clicks the Exit button on the Second pop-up window than both the window should Close at a time.
I know that for a different window I have to create a separate function to exit windows But I want to close more than one window with a single click.
I'm using python 3.7!
import tkinter
def NewWindow():
def qExit():
root.destroy()
root = tkinter.Tk()
root.title("New Window")
newButton = tkinter.Button(root, text=" Click here to Exit:",
command=qExit)
newButton.pack()
root.geometry("300x200")
root.mainloop()
Window = tkinter.Tk()
Window.title("hello")
eButton = tkinter.Button(Window, text="Start", command=NewWindow)
eButton.pack()
Window.geometry("200x200")
Window.mainloop()
You shouldn't call tkinter.Tk() more than once in a tkinter application. Call Toplevel() if you want to create a new window.
You also generally don't need to call mainloop() more than once.
To close both the new window and the main window, you can pass the latter to the former when you create it, and then destroy() that in your qExit() function (as well as the new window itself).
Note I changed some of the function and variable names to conform more to the PEP 8 - Style Guide for Python Code guidelines.
import tkinter
def makeWindow(parent):
def qExit():
newWindow.destroy()
parent.destroy()
newWindow = tkinter.Toplevel()
newWindow.geometry("300x200")
newWindow.title("New Window")
newButton = tkinter.Button(newWindow, text=" Click here to Exit",
command=qExit)
newButton.pack()
root = tkinter.Tk()
root.title("hello")
eButton = tkinter.Button(root, text="Start", command=lambda: makeWindow(root))
eButton.pack()
root.geometry("200x200")
root.mainloop()
A simple solution would be to just do exit() to stop the program, which will close all windows. alternatively you can make a list of all open window objects and call destroy on all of them.
No need description
def qExit():
root.destroy()
Window.destroy()
I'm developing a GUI application that models an essay. Among other things, the user can create a new topic and then populate that topic with notes. At the moment, I have two ways of creating new topics: through a dropdown option in the menu (the menu command) and through a button on the main screen (the button command). The button starts life with the text "New Topic". When the user presses the button, the program makes a new topic, asks the user to name the topic using tkSimpleDialog.askstring, and then sets the button's text to be the name of the topic and the number of notes in that topic. The button's command then changes to be adding a note to that topic.
While developing the program, I first verified that the menu command worked. It calls askstring successfully, creating a new popup window that handles input in the way I wanted. However, as soon as I added the button command, the call to askstring failed, even when called via the menu command. The window that should have the askstring dialog is whited out and the program hangs. If I comment out the button command, it works again. If I comment out the menu command, it hangs.
Here's the code where I add the command to the menu:
TopicBtn.menu.add_command(label="New Topic", underline=0,
command=self.newTopic)
Here's the code for newTopic():
def newTopic(self, button=None):
""" Create a new topic. If a Button object is passed, associate that Button
with the new topic. Otherwise, create a new Button for the topic. """
topicPrompt = "What would you like to call your new topic?"
topicName = tkSimpleDialog.askstring("New Topic", topicPrompt)
if topicName in self.topics.keys():
print "Error: topic already exists"
else:
newTopic = {}
newTopic["name"] = topicName
newTopic["notes"] = []
newTopic["button"] = self.newTopicButton(newTopic, button)
self.topics[topicName] = newTopic
self.addToTopicLists(newTopic)
Here's the code for newTopicButton():
def newTopicButton(self, topic, button=None):
""" If a Button object is passed, change its text to display the topic name.
Otherwise, create and grid a new Button with the topic name. """
if button is None:
button = Button(self.topicFrame)
index = len(self.topics)
button.grid(row=index/self.TOPICS_PER_ROW, column=(index %
self.TOPICS_PER_ROW), sticky=NSEW, padx=10, pady=10)
else:
button.unbind("<Button-1>")
buttonText = "%s\n0 notes" % topic["name"]
button.config(text=buttonText)
button.config(command=(lambda s=self, t=topic: s.addNoteToTopic(t)))
return button
And, finally, here's the code for the button command:
for col in range(self.TOPICS_PER_ROW):
button = Button(self.topicFrame, text="New Topic")
button.bind("<Button-1>", (lambda e, s=self: s.newTopic(e.widget)))
button.grid(row=0, column=col, sticky=NSEW, padx=10, pady=10)
Anybody have any idea why binding the lambda expression to the button makes askstring hang?
Edit: Thanks for the comments. Here's a minimal example that exhibits the behavior:
from Tkinter import *
import tkSimpleDialog
class Min():
def __init__(self, master=None):
root = master
frame = Frame(root)
frame.pack()
button = Button(frame, text="askstring")
button.bind("<Button-1>", (lambda e, s=self: s.newLabel()))
button.grid()
def newLabel(self):
label = tkSimpleDialog.askstring("New Label", "What should the label be?")
print label
root = Tk()
m = Min(root)
root.mainloop()
Note that switching from button.bind("<Button-1>", (lambda e, s=self: s.newLabel())) to button = Button(frame, text="askstring", command=(lambda s=self: s.newLabel())) fixes the bug (but doesn't give me a reference to the button that was pressed). I think the problem has something to do with capturing the event as one of the inputs to the lambda.
The problem you encountered here is due to the call to wait_window in the dialog you are using (you never call it yourself, but the code that implement the dialog does). For instance, the following code replicates the problem after (likely) two button clicks:
import Tkinter
def test(event=None):
tl = Tkinter.Toplevel()
tl.wait_window(tl)
root = Tkinter.Tk()
btn = Tkinter.Button(text=u'hi')
btn.bind('<Button-1>', test)
btn.pack(padx=10, pady=10)
root.mainloop()
This call to wait_window effectively does what the update command does, and is a typical example of why calling update is a bad thing to do. It enters in conflict with the <Button-1> event being handled, and hangs. The problem is that you will have to live with wait_window being used, since it belongs to the dialog's code. Apparently, if you bind to <ButtonRelease-1> then this conflict never happens. You could also use the command parameter in the button, which works fine too.
Lastly, I suggest the following to create the buttons in a cleaner manner based on what you want to achieve:
for i in range(X):
btn = Tkinter.Button(text=u'%d' % i)
btn['command'] = lambda button=btn: some_callback(button)
I figured out a workaround. From the minimum-example testing, it appears that the problem comes from making a separate call to bind and thereby accepting the event as an input to the lambda. If anyone can explain why that might be happening, I'll accept their answer over mine, but I'll accept this one for now.
The workaround is not to use a separate bind function but to create an array of buttons and then pass the correct entry in the array as the parameter to the lambda function (you can't pass the button itself, since it's being created in the line that has the lambda function).
Here's the code:
from Tkinter import *
import tkSimpleDialog
class Min():
def __init__(self, master=None):
root = master
frame = Frame(root)
frame.pack()
buttons = [None] * 2
for i in range (2):
buttons[i] = Button(frame, text="askstring",
command=(lambda s=self, var=i: s.newLabel(buttons[var])))
buttons[i].grid()
def newLabel(self, button):
label = tkSimpleDialog.askstring("New Label", "What should the label be?")
button.config(text=label)
print label
root = Tk()
m = Min(root)
root.mainloop()