在函数内部调用 FuncAnimation()

Question

我正在尝试在调用特定函数时执行 FuncAnimation()。但是，我的情节没有得到任何结果。

当 FuncAnimation 不在函数内部（或在 __init__() 内部）时，它可以完美运行。

我尝试了所有已发布的与该问题相关的解决方案，但它们在我的代码中不起作用。

我的简化代码是：

import sys
import os
from datetime import datetime
import matplotlib
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QApplication, QMainWindow, QVBoxLayout, QSizePolicy, QWidget
import numpy as np
import random
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
from matplotlib.animation import FuncAnimation

class MyMplCanvas(FigureCanvas):
    def __init__(self, parent=None, width=5, height=4, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi)

        self.ax = fig.add_subplot(1,1,1)

        FigureCanvas.__init__(self, fig)
        self.setParent(parent)
        FigureCanvas.setSizePolicy(self,
                                   QtWidgets.QSizePolicy.Expanding,
                                   QtWidgets.QSizePolicy.Expanding)
        FigureCanvas.updateGeometry(self)

class ApplicationWindow(QtWidgets.QMainWindow):
    def __init__(self):
        QtWidgets.QMainWindow.__init__(self)
        self.main_widget = QtWidgets.QWidget(self)
        self.canvas =  MyMplCanvas( self.main_widget,width=6, height=6, dpi=100) 

        self.xdata = []
        self.ydata = []

        vbox = QtWidgets.QVBoxLayout(self.main_widget)

        self.start_button = QtWidgets.QPushButton(text="START")
        self.outer_ani = self.start_button.clicked.connect(self.start_func_animation)

        vbox.addWidget(self.canvas)
        vbox.addWidget(self.start_button)
        self.setLayout(vbox)
        self.main_widget.setFocus()
        self.setCentralWidget(self.main_widget)

    def start_func_animation(self):
        self.line, = self.canvas.ax.plot_date(self.xdata, self.ydata, linestyle='-', linewidth=0.6, markersize=2.5)
        self.ani = FuncAnimation(self.canvas.figure, self.update_line, interval=1000)

        return self.ani

    def update_line(self, i):
        self.xdata.append(datetime.now())
        self.ydata.append(1+np.random.randint(-3,3))

        self.line.set_data(self.xdata, self.ydata)
        self.canvas.figure.gca().relim()
        self.canvas.figure.gca().autoscale_view()
        self.canvas.ax.tick_params(axis='x', rotation=50)

        return self.line,


if __name__ == "__main__":
    App = QApplication(sys.argv)
    aw = ApplicationWindow()
    aw.show()
    App.exit()
    sys.exit(App.exec_())

Answer 1

解决方案是为它更新绘画，有两种选择：使用self.canvas.draw() 或在FuncAnimation 中设置blit=True。

from datetime import datetime
import random
import os
import sys

from PyQt5 import QtCore, QtWidgets

import numpy as np

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
from matplotlib.animation import FuncAnimation


class MyMplCanvas(FigureCanvas):
    def __init__(self, parent=None, width=5, height=4, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi)

        self.ax = fig.add_subplot(1, 1, 1)

        FigureCanvas.__init__(self, fig)
        self.setParent(parent)
        FigureCanvas.setSizePolicy(
            self, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Expanding
        )
        FigureCanvas.updateGeometry(self)


class ApplicationWindow(QtWidgets.QMainWindow):
    def __init__(self):
        QtWidgets.QMainWindow.__init__(self)
        self.main_widget = QtWidgets.QWidget(self)
        self.canvas = MyMplCanvas(self.main_widget, width=6, height=6, dpi=100)

        self.xdata = []
        self.ydata = []

        vbox = QtWidgets.QVBoxLayout(self.main_widget)

        self.start_button = QtWidgets.QPushButton(text="START")
        # self.outer_ani = self.start_button.clicked.connect(self.start_func_animation)
        self.start_button.clicked.connect(self.start_func_animation)

        vbox.addWidget(self.canvas)
        vbox.addWidget(self.start_button)
        # self.setLayout(vbox)
        self.main_widget.setFocus()
        self.setCentralWidget(self.main_widget)

    def start_func_animation(self):
        (self.line,) = self.canvas.ax.plot_date(
            self.xdata, self.ydata, linestyle="-", linewidth=0.6, markersize=2.5
        )
        self.canvas.draw()
        self.ani = FuncAnimation(self.canvas.figure, self.update_line, interval=1000)
        # or
        # self.ani = FuncAnimation(self.canvas.figure, self.update_line, interval=1000, blit=True)
        # return self.ani

    def update_line(self, i):
        self.xdata.append(datetime.now())
        self.ydata.append(1 + np.random.randint(-3, 3))

        self.line.set_data(self.xdata, self.ydata)
        self.canvas.figure.gca().relim()
        self.canvas.figure.gca().autoscale_view()
        self.canvas.ax.tick_params(axis="x", rotation=50)

        return (self.line,)


if __name__ == "__main__":
    App = QtWidgets.QApplication(sys.argv)
    aw = ApplicationWindow()
    aw.show()
    # App.exit()
    sys.exit(App.exec_())