python - 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，例如矩形和文本。

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。

我也想让缩放对文本起作用，但我找不到这样做的方法。

任何帮助，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()

标签： pythontkintercanvasscroll

Answer 1

Ben Mega 的解决方案效果很好，并且很好地回答了这个问题。我只是在下面展示了一种在放大和缩小时实现字体大小更改的不同方式。

这个想法是为所有文本项使用一个公共tkinter.font.Font，这样我们就可以改变这个字体对象的大小，而不是重新配置所有的项目。然后可以使用全局更改字体大小.configure(size=<new size>)。

这是代码。我create_text()在类中添加了一个方法，Layout以避免在创建项目时手动设置字体。

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()