矩形补丁无法通过单击鼠标移动图像

Question

我在这里找到一个代码示例：how can move rectangle patch with click mouse python3，每次将鼠标移动到图形上的某个位置时，都允许使用鼠标移动矩形补丁，我想在图像上使用此示例并添加相同的内容并用鼠标移动ractangle我在图像上添加了矩形，但是我不能用鼠标移动

我需要一些帮助，如何在图像中移动例如矩形的示例：

import numpy as np
import netCDF4
from netCDF4 import Dataset
import matplotlib.pyplot as plt
import matplotlib.patches as patches



def on_press(event):
    xpress, ypress = event.xdata, event.ydata
    w = rect.get_width()
    h = rect.get_height()
    rect.set_xy((xpress-w/2, ypress-h/2))

    ax.lines = []  
    ax.axvline(xpress, c='b')
    ax.axhline(ypress, c='b')

    fig.canvas.draw()

fic='ainfrared_01905080000.nc'

path='/home/data/'

nc = netCDF4.Dataset(path+fic,'r')
IR=nc.variables['IR][:]
x = y = 500


# Display the image
axes = plt.subplot(111)
axes.imshow(IR,origin='lower', cmap=plt.cm.gist_yarg)


rect = patches.Rectangle((x,y),800,800,linewidth=1,edgecolor='g',facecolor='none')

# Add the patch to the Axes
axes.add_patch(rect)


plt.show()

提前谢谢