PySimpleGUI清除按钮未清除画布。图表将保留并添加到新图表中

import PySimpleGUI as sg

layout = [[sg.Graph(canvas_size=(400, 400), graph_bottom_left=(0, 0), graph_top_right=(400, 400), key='-GRAPH-')],
          [sg.Button('Clear', key='-CLEAR-'), sg.Button('Exit')]]

window = sg.Window('Canvas Example', layout)

def clear_canvas():
    graph = window['-GRAPH-']
    graph.erase()
    
    # 添加新的图表
    graph.draw_line((0, 0), (400, 400), color='red')

while True:
    event, values = window.read()
    
    if event == sg.WINDOW_CLOSED or event == 'Exit':
        break
    elif event == '-CLEAR-':
        clear_canvas()
        
window.close()