Tkinter on canvas resize scroll bar does not adjus

问题:

Although I believe my problem is simple, I just can't find an answer nor figure out how to fix this. Basically, I have a canvas that once a button is pressed it gets resized (like a zoom in), however, my scrolling bars do not adjust in order to cover the hole scrolling area.

Does anyone knows how to fix this?

Code: (somewhat nasty)

from Tkinter import *

class Graphic(Tk):  #Graphical Interface
    def __init__(self, x, y):

        #INITIALIZATION
        Tk.__init__(self)
        self.border = 10
        self.size_x = x
        self.size_y = y
        self.mouse = ""
        self.cross_list = []
        self.mode = ""  

        #SIZE
        self.app_sizex = 1800
        self.app_sizey = 1000


        self.title("Graphic")
        self.geometry(str(self.app_sizex+10) + "x" + str(self.app_sizey+40))

        #CANVAS + BORDER
        self.canvas = Canvas(self, width = self.app_sizex, height = self.app_sizey, scrollregion=(0,0,x,y))
        self.canvas.grid(row=0, column=0, sticky="nsew")
        self.canvas.create_line(self.border, self.border, self.border, y-self.border)
        self.canvas.create_line(x-self.border, self.border, x-self.border, y-self.border)
        self.canvas.create_line(self.border, self.border, x-self.border, self.border)
        self.canvas.create_line(self.border, y-self.border, x-self.border, y-self.border)
        self.cross_x = self.canvas.create_line(self.border, self.border, self.border, self.border)
        self.cross_y = self.canvas.create_line(self.border, self.border, self.border, self.border)

        #SCROLLING BARS
        self.vbar=Scrollbar(self,orient=VERTICAL)
        self.vbar.grid(row=0, column=1, sticky="ns")
        self.vbar.config(command=self.canvas.yview)
        self.hbar=Scrollbar(self,orient=HORIZONTAL)
        self.hbar.grid(row=2, column=0, sticky="ew")
        self.hbar.config(command=self.canvas.xview)
        self.canvas.config(xscrollcommand=self.hbar.set, yscrollcommand=self.vbar.set)

        #BUTTONS
        self.buttonframe = Frame(self)
            self.buttonframe.grid(row=1, column=0)        
            Button(self.buttonframe, text = "+", command=self.zoom_in).grid(row=0, column=0)
            Button(self.buttonframe, text = "-").grid(row=0, column=1)


        self.canvas.bind("<1>",     lambda event: self.canvas.focus_set())
        self.canvas.bind("a",  lambda event: self.canvas.xview_scroll(-1, "units"))
            self.canvas.bind("d", lambda event: self.canvas.xview_scroll( 1, "units"))
            self.canvas.bind("w",    lambda event: self.canvas.yview_scroll(-1, "units"))
            self.canvas.bind("s",  lambda event: self.canvas.yview_scroll( 1, "units"))
        self.canvas.focus_set() 

    def zoom_in(self):
        #Clean canvas
        self.canvas.delete("all")
        self.size_x = self.size_x * 1.1
        self.size_y = self.size_y * 1.1
        x=self.size_x
        y=self.size_y
        self.canvas.scrollregion=(0,0,self.size_x,self.size_y)
        self.canvas.create_line(self.border, self.border, self.border, y-self.border)
        self.canvas.create_line(x-self.border, self.border, x-self.border, y-self.border)
        self.canvas.create_line(self.border, self.border, x-self.border, self.border)
        self.canvas.create_line(self.border, y-self.border, x-self.border, y-self.border)

        #SCROLLING BARS
        self.vbar.config(command=self.canvas.yview)
        self.hbar.config(command=self.canvas.xview)
        self.canvas.config(xscrollcommand=self.hbar.set, yscrollcommand=self.vbar.set)

graphics_window = Graphic(1000, 1000)
graphics_window.mainloop()

回答1:

It took me a while without a Minimal, Complete, and Verifiable Example but I got something running that I think does what you had in mind. I took the liberty of adding something to look at when we zoomed. Check it out:

from tkinter import *

class zoomer(Tk):

    def __init__(self):
        x=100
        y=100
        Tk.__init__(self)
        self.border = 10
        self.size_x = x
        self.size_y = y

        #SIZE
        self.app_sizex = 200
        self.app_sizey = 200
        fontSize=int(x/20)

        self.title("Graphic")
        self.geometry(str(self.app_sizex+10) + "x" + str(self.app_sizey+40))

        #CANVAS + BORDER
        self.canvas = Canvas(self, width = self.app_sizex, height = self.app_sizey, scrollregion=(0,0,x,y))
        self.canvas.grid(row=0, column=0, sticky="nsew")
        self.canvas.create_line(self.border, self.border, self.border, y-self.border)
        self.canvas.create_line(x-self.border, self.border, x-self.border, y-self.border)
        self.canvas.create_line(self.border,   self.border, x-self.border, self.border)
        self.canvas.create_line(self.border, y-self.border, x-self.border, y-self.border)
        self.canvas.create_line(self.border,   self.border, x-self.border, y-self.border)
        text1=self.canvas.create_text(50, 50, fill="white",font=("Purisa", fontSize))
        self.canvas.itemconfig(text1, text="Graphic Text")

        #SCROLLING BARS
        self.vbar=Scrollbar(self,orient=VERTICAL)
        self.vbar.grid(row=0, column=1, sticky="ns")
        self.vbar.config(command=self.canvas.yview)
        self.hbar=Scrollbar(self,orient=HORIZONTAL)
        self.hbar.grid(row=2, column=0, sticky="ew")
        self.hbar.config(command=self.canvas.xview)
        self.canvas.config(xscrollcommand=self.hbar.set, yscrollcommand=self.vbar.set)

        #zoom button
        save_button = Button(self, text = "Zoom")
        save_button["command"] = lambda: self.zoom_in()
        save_button.grid(row=3, column = 0, pady = 5)

    def zoom_in(self):
        #Clean canvas
        self.canvas.delete("all")
        self.size_x = int(self.size_x * 1.1)
        self.size_y = int(self.size_y * 1.1)
        x=self.size_x
        y=self.size_y
        fontSize=int(x/20)
        self.canvas.create_line(self.border, self.border, self.border, y-self.border)
        self.canvas.create_line(x-self.border, self.border, x-self.border, y-self.border)
        self.canvas.create_line(self.border, self.border, x-self.border, self.border)
        self.canvas.create_line(self.border, y-self.border, x-self.border, y-self.border)
        self.canvas.create_line(self.border,   self.border, x-self.border, y-self.border)
        text1=self.canvas.create_text(self.size_x/2, self.size_y/2, fill="white",font=("Purisa", fontSize) )
        self.canvas.itemconfig(text1, text="Graphic Text")
        self.canvas.configure(scrollregion=self.canvas.bbox("all"))

        #SCROLLING BARS
        self.vbar.config(command=self.canvas.yview)
        self.hbar.config(command=self.canvas.xview)
        self.canvas.config(xscrollcommand=self.hbar.set, yscrollcommand=self.vbar.set)


if __name__ == '__main__':
    my_gui=zoomer()
    my_gui.mainloop()

I will leave what you were missing as an exercise. (That means I got it running but am too lazy to go back and figure out exactly what went wrong.)