for 循环中的 Tkinter GUI

Question

我正在为我的程序做一个 tkinter GUI，我必须显示一些实时数据。我做了一个简单的程序（如下）来在一个简单的案例中演示我的问题。实际上，我在 for 循环的每次迭代中都绘制了一些数据，这样我就可以在程序仍在计算的同时观察数据。请注意，真正的程序 si 计算速度有点慢并且有更多的迭代。

现在我想添加 2 个按钮（一个用于暂停程序，一个用于继续）和一个标签（显示变量 k，以便我知道我的程序在哪里），但我无法这样做。

我已经在这上面浪费了很多时间，所以如果有人有提示或解决方案，我很乐意看到它。

import tkinter as tk
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2Tk
import matplotlib.pyplot as plt
from matplotlib import style

def func_A(a, x):
    import numpy
    data_x = numpy.arange(0, x)
    data_y = a * numpy.sin(data_x/5)
    return data_x, data_y

a = 1

root = tk.Tk()
root.title("Graph")
root.geometry("800x400")

fig = plt.figure(figsize=(5, 5), dpi=100)
canvas = FigureCanvasTkAgg(fig, master=root)  # A tk.DrawingArea.
canvas.draw()
canvas.get_tk_widget().pack(side=tk.TOP, fill=tk.BOTH, expand=1)

toolbar = NavigationToolbar2Tk(canvas, root)
toolbar.update()
canvas.get_tk_widget().pack(side=tk.TOP, fill=tk.BOTH, expand=1)

plt.grid("both")
style.use("ggplot")
for k in range(0, 100):
    data_x, data_y = func_A(a, k)
    print("iteration", k)
    print("data_x", data_x)
    print("data_y", data_y)
    if k == 0:
        ax1 = plt.subplot(111)
        line1, = ax1.plot([0], [0])
    else:
        line1.set_xdata(data_x)
        line1.set_ydata(data_y)

    ax1.set_ylim([-1, 1])
    ax1.set_xlim([0, 100])
    plt.grid("both")
    canvas.draw()
    canvas.flush_events()
root.mainloop()

Answer 1

添加pause/resume功能：

创建一个框架来保存进度标签和两个按钮：暂停和恢复
创建一个 tkinter BooleanVar() 来存储 pause/resume 状态
将更新绘图代码移到一个函数中，例如update_plot()
使用.after()代替for循环周期性调用update_plot()
在update_plot()里面，检查pause/resume状态来决定是否更新剧情

下面是根据您的代码修改的示例：

import tkinter as tk
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg, NavigationToolbar2Tk
import matplotlib.pyplot as plt
from matplotlib import style
import matplotlib
matplotlib.use("Agg")

root = tk.Tk()
root.title("Graph")
#root.geometry("800x400")

# progress label, pause and resume buttons
frame = tk.Frame(root)
frame.pack(fill="x", side=tk.TOP)

progress = tk.Label(frame)
progress.pack(side="left")

is_paused = tk.BooleanVar()  # variable to hold the pause/resume state
tk.Button(frame, text="Pause", command=lambda: is_paused.set(True)).pack(side="right")
tk.Button(frame, text="Resume", command=lambda: is_paused.set(False)).pack(side="right")

# the plot

fig = plt.figure(figsize=(10, 5), dpi=100)

canvas = FigureCanvasTkAgg(fig, master=root)
toolbar = NavigationToolbar2Tk(canvas, root)
canvas.get_tk_widget().pack(side=tk.TOP, fill=tk.BOTH, expand=1)

plt.grid("both")
style.use("ggplot")

a = 1
ax1 = plt.subplot(111)
line1, = ax1.plot([0], [0])

def func_A(a, x):
    import numpy
    data_x = numpy.arange(0, x)
    data_y = a * numpy.sin(data_x/5)
    return data_x, data_y

# function to update ploat
def update_plot(k=0):
    if not is_paused.get():
        progress["text"] = f"iteration: {k}"

        data_x, data_y = func_A(a, k)
        #print("iteration", k)
        #print("data_x", data_x)
        #print("data_y", data_y)

        line1.set_xdata(data_x)
        line1.set_ydata(data_y)

        ax1.set_ylim([-1, 1])
        ax1.set_xlim([0, 100])
        plt.grid("both")
        canvas.draw()
        canvas.flush_events()
        k += 1
    if k <= 100:
        # update plot again after 10ms. You can change the delay to whatever you want
        root.after(10, update_plot, k)

update_plot() # start updating plot
root.mainloop()

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