如何使用 Tkinter 中的 Checkbuttom 隐藏或显示由滑块控制的画布线？

Question

使用下面的代码可以控制三角信号的幅度和频率。
刚开始使用 Python，我无法使用

Checkbutton

中的

tkinter

隐藏或显示给定信号。在互联网上找到的几个例子适用于标签文本或图像，但不适用于通过函数控制的画布对象......
感谢您的帮助

import tkinter as tk
from tkinter import ttk
import numpy as np
from scipy import signal as sg

root = tk.Tk()
root.title('Oscilloscope')
root.geometry("1000x600+0+0")

N1 = 2000
X1 = 1000
O1 = 200

# canva
cnv = tk.Canvas(root, width = 800, height = 400, bg = 'white')
cnv.place(relx=0.5, rely=0.3, anchor=tk.CENTER)
cnv.create_line(400, 0, 400, 400, fill='black', width=1)
cnv.create_line(0, 200, 1000, 200, fill='black', width=1)

# sliders labels
amplitude = ttk.Label(root, text="Amplitude", font=("Arial", 12, "bold"), foreground="black")
amplitude.place(relx=0.3, rely=0.7, anchor=tk.CENTER)
frequence = ttk.Label(root, text="Frequency", font=("Arial", 12, "bold"), foreground="black")
frequence.place(relx=0.7, rely=0.7, anchor=tk.CENTER)

# signal
def draw1(cnv, A1, F1, O1, N1):
    cnv.delete("line1")
    xpts1 = X1 / (N1-1)
    line1 = []
    for i in range(N1):
        x = (i * xpts1)
        y = A1*sg.sawtooth(2*np.pi*F1*i/N1, width=0.5) + O1
        line1.extend((x, y))
    cnv.create_line(line1, fill="red2", width=3, tag="line1")

# control sliders
def ctrl_curseurs_1(*args):
    A1 = A1_valeur.get()
    F1 = F1_valeur.get()
    draw1(cnv, A1, F1, O1, N1)

# horizontal slider for amplitude A1 ############################
def curseur_A1():
    sel = "Value = " + str(value.get(A1))
A1_valeur = tk.IntVar()
A1_frm = ttk.Frame(root)
A1_frm.place(relx=0.3, rely=0.8, anchor=tk.CENTER)
A1_scale = tk.Scale(A1_frm, variable=A1_valeur, command=ctrl_curseurs_1,
                           from_ = -200, to = 200, length=200, showvalue=1, tickinterval=100, orient = tk.HORIZONTAL, resolution=1)
A1_scale.pack(anchor=tk.CENTER)

# horizontal slider for frequency F1 ############################
def curseur_F1():
    sel = "Value = " + str(value.get(F1))
F1_valeur = tk.IntVar()
F1_frm = ttk.Frame(root)
F1_frm.place(relx=0.7, rely=0.8, anchor=tk.CENTER)
F1_scale = tk.Scale(F1_frm, variable=F1_valeur, command=ctrl_curseurs_1,
                           from_ = 0, to = 50, length=200, showvalue=1, tickinterval=10, orient = tk.HORIZONTAL, resolution=1)
F1_scale.pack(anchor=tk.CENTER)

root.mainloop()

Answer 1

考虑两件事：

• 您可以使用

  state

  属性设置是否显示画布项目，该属性接受

  "hidden"

  和

  "normal"

  作为值。

• 创建项目后，您可以使用

  canvas.itemconfigure

  修改该状态。

有了它，你可以做类似的事情：

import tkinter as tk
from tkinter import ttk
import numpy as np
from scipy import signal as sg

root = tk.Tk()
root.title('Oscilloscope')
root.geometry("1000x600+0+0")

N1 = 2000
X1 = 1000
O1 = 200

# canvas
cnv = tk.Canvas(root, width = 800, height = 400, bg = 'white')
cnv.place(relx=0.5, rely=0.3, anchor=tk.CENTER)
cnv.create_line(400, 0, 400, 400, fill='black', width=1)
cnv.create_line(0, 200, 1000, 200, fill='black', width=1)

# sliders labels
amplitude = ttk.Label(root, text="Amplitude", font=("Arial", 12, "bold"), foreground="black")
amplitude.place(relx=0.3, rely=0.7, anchor=tk.CENTER)
frequence = ttk.Label(root, text="Frequency", font=("Arial", 12, "bold"), foreground="black")
frequence.place(relx=0.7, rely=0.7, anchor=tk.CENTER)

# signal
def draw1(cnv, A1, F1, O1, N1):
    cnv.delete("line1")
    xpts1 = X1 / (N1-1)
    line1 = []
    for i in range(N1):
        x = (i * xpts1)
        y = A1*sg.sawtooth(2*np.pi*F1*i/N1, width=0.5) + O1
        line1.extend((x, y))
    cnv.create_line(
        line1, fill="red2", width=3, tag="line1",
        state='normal' if check_control_1.get() else 'hidden'
        )

# control sliders
def ctrl_curseurs_1(*args):
    A1 = A1_valeur.get()
    F1 = F1_valeur.get()
    draw1(cnv, A1, F1, O1, N1)

# horizontal slider for amplitude A1 ############################
def curseur_A1():
    sel = "Value = " + str(value.get(A1))

A1_valeur = tk.IntVar()
A1_frm = ttk.Frame(root)
A1_frm.place(relx=0.3, rely=0.8, anchor=tk.CENTER)
A1_scale = tk.Scale(A1_frm, variable=A1_valeur, command=ctrl_curseurs_1,
                           from_ = -200, to = 200, length=200, showvalue=1, tickinterval=100, orient = tk.HORIZONTAL, resolution=1)
A1_scale.pack(anchor=tk.CENTER)

# horizontal slider for frequency F1 ############################
def curseur_F1():
    sel = "Value = " + str(value.get(F1))

F1_valeur = tk.IntVar()
F1_frm = ttk.Frame(root)
F1_frm.place(relx=0.7, rely=0.8, anchor=tk.CENTER)
F1_scale = tk.Scale(F1_frm, variable=F1_valeur, command=ctrl_curseurs_1,
                           from_ = 0, to = 50, length=200, showvalue=1, tickinterval=10, orient = tk.HORIZONTAL, resolution=1)
F1_scale.pack(anchor=tk.CENTER)

check_control_1 = tk.BooleanVar(root, value=False)
ttk.Checkbutton(
    root,
    text="Signal 1",
    variable=check_control_1,
    command=lambda: cnv.itemconfigure(
        "line1", state='normal' if check_control_1.get() else 'hidden')
    ).place(
        relx=0.5, rely=0.8, anchor=tk.CENTER
        )

root.mainloop()