Python GUI Programming (Tkinter)

Python3 Previous version with Tkinter, followed by Tkinter

The simplest code to use Tkinter is to first create a window of TK () and then add the various widgets

From Tkinter Import *window = Tk () label = label (window, Text = "Welcome to Python") button = button (window, Text = "click M E ") Label.pack () Button.pack () Window.mainloop ()

Tkinter programming is event-driven, and when a button is clicked, the event can be handled by a function

From Tkinter import *def Processok ():    print ("OK") def processcancel ():    print ("Cancel") window = Tk () Btok = Button (window, Text = "OK", FG = "Red", command = processok) btcancel = button (window, text = "Cancel", bg = "yellow", command = Processcancel) Btok.pack () Btcancel.pack () Window.mainloop ()

Where the parameter command is the bound function

There are also a variety of widgets available Classes

• Button
• Canvas
• Checkbutton
• Entry
• Frame
• Label
• Menu
• Menubutton
• Message
• Radiobutton
• Text

You can modify one of the Widget's properties directly:

btshoworhide = button (window, text = "Show", bg = "white") btshoworhide["text"] = "Hide" btshoworhide["bg"] = "Red" Btshoworh Ide["FG"] = "#AB84F9" # change FG color to #AB84F9btShowOrHide ["cursor"] = "plus" # change mouse cursor to Plusbtshoworhid E["justify"] = left # Set justify to left

Intvar (), Stringvar ()

From Tkinter import *class widgetsdemo:def __init__ (self): window = Tk () window.title (' Widgets Demo ') frame1 = Frame (window) frame1.pack () self.v1 = Intvar () self.v2 = Intvar () rbred = Radiobutton (frame1, Text = "Red", BG = "Red", variable = self.v2, value = 1, command = Self.processradiobutton) r Byellow = Radiobutton (frame1, Text = "Yellow", bg = "Yellow", variable = self.v2, value = 2, command = Self.processradiobu Tton) Rbred.grid (row = 1, column = 2) rbyellow.grid (row = 1, column = 3) frame2 = Frame (windo W) frame2.pack () label = label (frame2, Text = "Enter Your Name:") Self.name = Stringvar () en Tryname = Entry (frame2, textvariable = self.name) btgetname = button (frame2, Text = "Get name", command = Self.proc Essbutton) message = Message (frame2, Text = "It is a widgets demo") Label.grid (row = 1, column = 1) E Ntryname.grid (row = 1, cOlumn = 2) btgetname.grid (row = 1, column = 3) message.grid (row = 1, column = 4) window.mainl            OOP () def Processradiobutton (self): print (("Red" if self.v2.get () = = 1 Else "Yellow") + "is selected") def Processbutton (self): print ("Your name is" + self.name.get ()) Widgetsdemo ()

The keys of the two colors in the above code are bound to the Intvar () type variable, assigning values of 1 and 2 respectively, then the value of Intvar () can be obtained with get (), while the input text window binds the string variable stringvar ()

Canvas: Can be used to show some graphics

From Tkinter import *class canvasdemo:    def __init__ (self):        window = Tk ()        window.title ("Canvas demo")                Self.canvas = canvas (window, width = max, height = +, bg = "white")        Self.canvas.pack ()                frame = frame (window) 
   
    frame.pack ()        btrectangle = button (frame, text = "Tectangle", command = self.displayrect)        btrectangle.grid (row = 1, column = 1)                Window.mainloop ()            def displayrect (self):        self.canvas.create_rectangle (10, 10, 190, 90, tags = "rect")    Canvasdemo ()
   

Menus

menubar = menu (window) window.config (menu = menubar) # Display the menu Baroperationmenu = Menu (menubar, tearoff = 0) Menuba R.add_cascade (label = "Operation", menu = operationmenu) # header Operationmenu.add_command (label = "Add", command = Self.add) Operationmenu.add_command (...) # add menu option Exitmenu = Menu (menubar, tearoff = 0) menubar.add_cascade (label = "Exit", menu = Exi Tmenu) exitmenu.add_command (label = "Quit", command = window.quit)

Popup Menus

From Tkinter import *class popupmenudemo:    def __init__ (self):        window = Tk ()        window.title ("popup Menu Demo")                Self.menu = menu (window, tearoff = 0)        self.menu.add_command (label = "Draw a line", command = self.displayline) 
   self.menu.add_command (label = "Draw an oval", command = ...)            def displayline (self):        ...

Mouse, Key events, and Bindings

Widget.bind (event, handler)}}}{{{class = "Brush:python" Def popup (Event):    menu.post (Event.x_root,event.y_root)

Event	Description
<Bi-Motion>	An event occurs if a mouse button is moved and being held down on the widget.
<Button-i>	Button-1, Button-2, and Button-3 identify the left, middle, and right buttons. When a mouse button was pressed over the widget, Tkinter automatically grabs the mouse pointer's location. Buttonpressed-i is synonymous with button-i.
<ButtonReleased-i>	An event occurs if a mouse button is released.
<Double-Button-i>	An event occurs if a mouse button is double-clicked.
<Enter>	An event occurs when a mouse pointer enters the widget.
<Key>	An event occurs if a key is pressed.
<Leave>	An event occurs when a mouse pointer leaves the widget.
<Return>	An event occurs when the Enter key is pressed. You can bind any key such as A, B, up, down, left, right in the keyboard with an event.
<Shift+A>	An event occurs when the Shift+a keys is pressed. You can combine Alt, Shift, and Control with the other keys.
<Triple-Button-i>	An event occurs if a mouse button is triple-clicked.

Event Properties

Event Properties	Description
char	the CH Aracter entered from the keyboard for key events.
keycode	the key code (i.e, Unicode) for the key entered from the keyboard for key events.
keysym	the key symbol (i.e., character) for the key entered from the keyboard for Key events.
num	the button number (1, 2, 3) indicates which mouse button was clicked.
widget	The Widget object that fires this event.
x and y	the current mouse location in the widgets in pixels.
x_ root and Y_root	the current mouse position relative to the upper-left corner of the SCR Een, in pixels.

From Tkinter import *class mousekeyeventdemo:    def __init__ (self):        window = Tk ()        Window.title ("event demo")        canvas = canvas (window, BG = "white", width = max, height = +)        canvas.pack ()                # Bind with <Button-1> E Vent        canvas.bind ("<Button-1>", self.processmouseevent)                # Bind with <Key> event        Canvas.bind ( "<Key>", Self.processkeyevent)        Canvas.focus_set () # set keyboard focus                Window.mainloop () def on this            window Processmouseevent (self, event):        print ("clicked at", Event.x, Event.y) # Coordinates in the current window        print ("position in the Screen ", Event.x_root, Event.y_root) # The coordinates print in the entire display        (" which button is clicked? ", Event.num)            def Processkeyevent (self, event): Print ("        keysym?", Event.keysym) print ("        char?", Event.char)        print (" KeyCode? ", Event.keycode)        Mousekeyeventdemo ()

Operation Result:

(' clicked at ', 109, 53) (' position in the screen ', 908, 105) (' Which button is clicked? ', 1) (' Keysym? ', ' shift_l ') (' char? ', ') (' KeyCode? ', 50)

Animations

# coding:utf-8from Tkinter Import *class animationdemo:    def __init__ (self):        window = Tk ()        window.title (" Event Demo ")                width = # width        canvas = canvas (window, BG =" white ", Width = width, height =)        canvas.pack ()                x = 0 # initial position        Canvas.create_text (x, 3, Text = "message moving?", tags = "text")                dx = # each move distance while        T Rue:            canvas.move ("text", DX, 0)            canvas.after (100) # Stop 100 ms            canvas.update ()            if x < width:                x + = dx            else:                x = 0                canvas.delete ("text")                canvas.create_text (x, page, Text = "message moving?", tags = "text")                        Window.mainloop ()        Animationdemo ()

Scrollbars

ScrollBar = ScrollBar (frame) scrollbar.pack (side = right, fill = Y) Text = text (frame, wrap = WORD, Yscrollcommand = scrollb Ar.set) Text.pack () scrollbar.config (command = Text.yview)

Standard Dialog Boxes

#coding: Utf-8import tkcolorchooserimport tkmessageboximport tksimpledialogtkmessagebox.showinfo ("Hello", "some info ") tkmessagebox.showwarning (title, message) Tkmessagebox.showerror (title, message) Isyes = Tkmessagebox.askyesno (" AskYesNo "," Continue? ") Print (isyes) name = tksimpledialog.askstring ("askstring", "Your name?") Print (name) height = tksimpledialog.askfloat ("Askfloat", "your height?") Print (height)