如何放大和缩小画布中的文本大小，tkinter python

Question

我创建了一个画布小部件，并添加了一些对象，如矩形和文本

我还将缩放功能绑定到鼠标滚轮。它适用于矩形；但是，它不适用于文本

我想让文本的缩放也能正常工作，但我找不到方法

任何帮助都将不胜感激

class Layout(tk.Frame):

    def __init__(self, root):
        tk.Frame.__init__(self, root)[![enter image description here][1]][1]
        self.canvas = tk.Canvas(self, width=200, height=750, background="white")
        self.xsb = tk.Scrollbar(self, orient="horizontal", command=self.canvas.xview)
        self.ysb = tk.Scrollbar(self, orient="vertical", command=self.canvas.yview)
        self.canvas.configure(yscrollcommand=self.ysb.set, xscrollcommand=self.xsb.set)
        self.canvas.configure(scrollregion=(0,0,1000,1000))

        self.xsb.grid(row=1, column=0, sticky="ew")
        self.ysb.grid(row=0, column=1, sticky="ns")
        self.canvas.grid(row=0, column=0, sticky="nsew")
        self.grid_rowconfigure(0, weight=1)
        self.grid_columnconfigure(0, weight=1)

        #self.canvas.create_text(50,10, text="Click and drag to move the canvas\nScroll to zoom.")

        # This is what enables using the mouse:
        self.canvas.bind("<ButtonPress-1>", self.move_start)
        self.canvas.bind("<B1-Motion>", self.move_move)
        #linux scroll
        self.canvas.bind("<Button-4>", self.zoomerP)
        self.canvas.bind("<Button-5>", self.zoomerM)
        #windows scroll
        self.canvas.bind("<MouseWheel>",self.zoomer)

    #move
    def move_start(self, event):
        self.canvas.scan_mark(event.x, event.y)
    def move_move(self, event):
        self.canvas.scan_dragto(event.x, event.y, gain=1)

    #windows zoom
    def zoomer(self,event):
        if (event.delta > 0):
            self.canvas.scale("all", event.x, event.y, 1.1, 1.1)
        elif (event.delta < 0):
            self.canvas.scale("all", event.x, event.y, 0.9, 0.9)
        self.canvas.configure(scrollregion = self.canvas.bbox("all"))

    #linux zoom
    def zoomerP(self,event):
        self.canvas.scale("all", event.x, event.y, 1.1, 1.1)
        self.canvas.configure(scrollregion = self.canvas.bbox("all"))
    def zoomerM(self,event):
        self.canvas.scale("all", event.x, event.y, 0.9, 0.9)
        self.canvas.configure(scrollregion = self.canvas.bbox("all"))


root = Tk()
root.title("Seoul Cell")
root.geometry("1300x1000")
root.resizable(True, True)

if __name__ == "__main__":

    global monitor1
    monitor1 = Layout(root)
    monitor1.pack(fill="both", expand=True)


for i in range(10):
    x1= random.randrange(0, 1000)
    x2 = random.randrange(0, 1000)
    y1 = random.randrange(0, 1000)
    y2 = random.randrange(0, 1000)
    monitor1.canvas.create_rectangle(x1, x2, y1, y2, fill = "black", stipple= "gray50")
    monitor1.canvas.create_text(x1, y1, text = "random word!", font = ("Helvetica", 10))
root.mainloop()

Answer 1

缩放画布不起作用的原因是文本字体大小被固定在10。要解决这个问题，我们需要为字体大小添加一个属性，缩放它，然后修改文本小部件。这是不完美的，因为事实上你不能做分数字体大小，但我认为它的作品好

这是修改后的代码

import tkinter as tk
from tkinter import Tk
import random


#fontSize = 10

class Layout(tk.Frame):

    def __init__(self, root):
        tk.Frame.__init__(self, root) #[![enter image description here][1]][1]
        self.canvas = tk.Canvas(self, width=200, height=750, background="white")
        self.xsb = tk.Scrollbar(self, orient="horizontal", command=self.canvas.xview)
        self.ysb = tk.Scrollbar(self, orient="vertical", command=self.canvas.yview)
        self.canvas.configure(yscrollcommand=self.ysb.set, xscrollcommand=self.xsb.set)
        self.canvas.configure(scrollregion=(0,0,1000,1000))

        self.xsb.grid(row=1, column=0, sticky="ew")
        self.ysb.grid(row=0, column=1, sticky="ns")
        self.canvas.grid(row=0, column=0, sticky="nsew")
        self.grid_rowconfigure(0, weight=1)
        self.grid_columnconfigure(0, weight=1)

        self.canvas.fontSize = 10
        #self.canvas.create_text(50,10, text="Click and drag to move the canvas\nScroll to zoom.")

        # This is what enables using the mouse:
        self.canvas.bind("<ButtonPress-1>", self.move_start)
        self.canvas.bind("<B1-Motion>", self.move_move)
        #linux scroll
        self.canvas.bind("<Button-4>", self.zoomerP)
        self.canvas.bind("<Button-5>", self.zoomerM)
        #windows scroll
        self.canvas.bind("<MouseWheel>",self.zoomer)

    #move
    def move_start(self, event):
        self.canvas.scan_mark(event.x, event.y)

    def move_move(self, event):
        self.canvas.scan_dragto(event.x, event.y, gain=1)

    #windows zoom
    def zoomer(self,event):
        if (event.delta > 0):
            self.canvas.scale("all", event.x, event.y, 1.1, 1.1)
            self.canvas.fontSize = self.canvas.fontSize * 1.1
        elif (event.delta < 0):
            self.canvas.scale("all", event.x, event.y, 0.9, 0.9)
            self.canvas.fontSize = self.canvas.fontSize * 0.9
        for child_widget in self.canvas.find_withtag("text"):
            self.canvas.itemconfigure(child_widget, font = ("Helvetica", int(self.canvas.fontSize)))
        self.canvas.configure(scrollregion = self.canvas.bbox("all"))

    #linux zoom
    def zoomerP(self,event):
        self.canvas.fontSize = self.canvas.fontSize * 1.1
        self.canvas.scale("all", event.x, event.y, 1.1, 1.1)
        for child_widget in self.canvas.find_withtag("text"):
            self.canvas.itemconfigure(child_widget, font = ("Helvetica", int(self.canvas.fontSize)))
        self.canvas.configure(scrollregion = self.canvas.bbox("all"))

    def zoomerM(self,event):
        self.canvas.fontSize = self.canvas.fontSize * 0.9
        self.canvas.scale("all", event.x, event.y, 0.9, 0.9)
        for child_widget in self.canvas.find_withtag("text"):
            self.canvas.itemconfigure(child_widget, font = ("Helvetica", int(self.canvas.fontSize)))
        self.canvas.configure(scrollregion = self.canvas.bbox("all"))


root = Tk()
root.title("Seoul Cell")
root.geometry("1300x1000")
root.resizable(True, True)

if __name__ == "__main__":

    global monitor1
    monitor1 = Layout(root)
    monitor1.pack(fill="both", expand=True)


for i in range(10):
    x1= random.randrange(0, 1000)
    x2 = random.randrange(0, 1000)
    y1 = random.randrange(0, 1000)
    y2 = random.randrange(0, 1000)
    monitor1.canvas.create_rectangle(x1, x2, y1, y2, fill = "black", stipple= "gray50")
    monitor1.canvas.create_text(x1, y1, text = "random word!", font = ("Helvetica", 10), tags="text")
root.mainloop()

Answer 2

Ben Mega的解决方案很好地解决了这个问题。我只是在下面展示了一种在放大和缩小时实现fontsize更改的不同方法

其思想是对所有文本项使用公共tkinter.font.Font，这样我们就可以更改此字体对象的大小，而不是重新配置所有项。然后可以使用.configure(size=<new size>)全局更改字体大小

这是代码。我在Layout类中添加了一个create_text()方法，以避免在创建项目时必须手动设置字体

import tkinter as tk
from tkinter.font import Font
import random

class Layout(tk.Frame):

    def __init__(self, root):
        tk.Frame.__init__(self, root)
        self.font = Font(self, "Arial 10")  # create font object
        self.fontsize = 10  # keep track of exact fontsize which is rounded in the zoom

        self.canvas = tk.Canvas(self, width=200, height=750, background="white")
        self.xsb = tk.Scrollbar(self, orient="horizontal", command=self.canvas.xview)
        self.ysb = tk.Scrollbar(self, orient="vertical", command=self.canvas.yview)
        self.canvas.configure(yscrollcommand=self.ysb.set, xscrollcommand=self.xsb.set)
        self.canvas.configure(scrollregion=(0,0,1000,1000))

        self.xsb.grid(row=1, column=0, sticky="ew")
        self.ysb.grid(row=0, column=1, sticky="ns")
        self.canvas.grid(row=0, column=0, sticky="nsew")
        self.grid_rowconfigure(0, weight=1)
        self.grid_columnconfigure(0, weight=1)

        # This is what enables using the mouse:
        self.canvas.bind("<ButtonPress-1>", self.move_start)
        self.canvas.bind("<B1-Motion>", self.move_move)
        #linux scroll
        self.canvas.bind("<Button-4>", self.zoomerP)
        self.canvas.bind("<Button-5>", self.zoomerM)
        #windows scroll
        self.canvas.bind("<MouseWheel>",self.zoomer)


    #create text
    def create_text(self, *args, **kwargs):
        self.canvas.create_text(*args, **kwargs, font=self.font)

    #move
    def move_start(self, event):
        self.canvas.scan_mark(event.x, event.y)

    def move_move(self, event):
        self.canvas.scan_dragto(event.x, event.y, gain=1)

    #windows zoom
    def zoomer(self,event):
        if (event.delta > 0):
            self.fontsize *= 1.1
            self.canvas.scale("all", event.x, event.y, 1.1, 1.1)
        elif (event.delta < 0):
            self.fontsize *= 0.9
            self.canvas.scale("all", event.x, event.y, 0.9, 0.9)
        self.font.configure(size=int(self.fontsize))  # update fontsize
        self.canvas.configure(scrollregion = self.canvas.bbox("all"))

    #linux zoom
    def zoomerP(self,event):
        self.fontsize *= 1.1
        self.font.configure(size=int(self.fontsize))
        self.canvas.scale("all", event.x, event.y, 1.1, 1.1)
        self.canvas.configure(scrollregion = self.canvas.bbox("all"))

    def zoomerM(self,event):
        self.fontsize *= 0.9
        self.font.configure(size=int(self.fontsize))
        self.canvas.scale("all", event.x, event.y, 0.9, 0.9)
        self.canvas.configure(scrollregion = self.canvas.bbox("all"))

root = tk.Tk()
root.title("Seoul Cell")
root.geometry("1300x1000")
root.resizable(True, True)

monitor1 = Layout(root)
monitor1.pack(fill="both", expand=True)

for i in range(10):
    x1= random.randrange(0, 1000)
    x2 = random.randrange(0, 1000)
    y1 = random.randrange(0, 1000)
    y2 = random.randrange(0, 1000)
    monitor1.canvas.create_rectangle(x1, x2, y1, y2, fill = "black", stipple= "gray50")
    monitor1.create_text(x1, y1, text="random word!")
root.mainloop()