# -*- coding: utf-8 -*-
'''
TODO:LQD
'''
import sys
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FC
from PyQt5.QtWidgets import QApplication, QPushButton, QMainWindow, QVBoxLayout, QWidget
 
 
class QtDraw(QMainWindow):
  flag_btn_start = True
 
  def __init__(self):
    super(QtDraw, self).__init__()
    self.init_ui()
 
  def init_ui(self):
    self.resize(800, 600)
    self.setWindowTitle('PyQt5 Draw')
 
    # TODO:这里是结合的关键
    self.fig = plt.Figure()
    self.canvas = FC(self.fig)
    self.btn_start = QPushButton(self)
    self.btn_start.setText('draw')
    self.btn_start.clicked.connect(self.slot_btn_start)
 
    widget = QWidget()
    layout = QVBoxLayout()
    layout.addWidget(self.canvas)
    layout.addWidget(self.btn_start)
    widget.setLayout(layout)
    self.setCentralWidget(widget)
 
  def slot_btn_start(self):
    try:
      ax = self.fig.add_subplot(111)
      x = np.linspace(0, 100, 100)
      y = np.random.random(100)
      ax.cla() # TODO:删除原图，让画布上只有新的一次的图
      ax.plot(x, y)
      self.canvas.draw() # TODO:这里开始绘制
    except Exception as e:
      print(e)
 
 
def ui_main():
  app = QApplication(sys.argv)
  w = QtDraw()
  w.show()
  sys.exit(app.exec_())
 
 
if __name__ == '__main__':
  ui_main()
