PySimpleGUI 不返回任何内容答案

【问题标题】：PySimpleGUI returning nonePySimpleGUI 不返回任何内容
【发布时间】：2020-08-03 03:12:00
【问题描述】：

当我执行这段代码时，我不明白为什么在我按下后退按钮后它给出了一个无。这段代码的主要目的是从一个窗口切换到另一个窗口。

import PySimpleGUI as sg
 
class Canvas:
    
    def __init__(self):
        buttons=[['Safe', 'Env', 'Health', 'Quali'],
        ['Forms','Checklist','Photos','Back']
              ]
        #Layout
        lt = [[sg.Button(i)] for i in buttons[0]]
        lt2 = [[sg.Button(i)] for i in buttons[1]]
        #Janela
        self.windows = [sg.Window('A').Layout(lt),sg.Window('S').Layout(lt2)]

    def Begin(self):
        i=0
        while True:
            self.event, self.values = self.windows[i].Read()
         
            #When pressing the button, changing the window
            if self.event == 'Safe':
                self.windows[i].Close() 
                i=1
            if self.event == 'Back':
                i=0
            #Closing part
            if self.event in (None, 'Exit'):
                break

cv = Canvas()
cv.Begin()

【问题讨论】：

标签： button pysimplegui

【解决方案1】：

这可能对你有用：

import PySimpleGUI as sg
 
class Canvas:
    
    def __init__(self):
        self.buttons=[['Safe', 'Env', 'Health', 'Quali'],
        ['Forms','Checklist','Photos','Back']
              ]
        #Layout
        self.lt = [[sg.Button(i)] for i in self.buttons[0]]
        #Janela

    def Begin(self):
        self.windows = sg.Window('A').Layout(self.lt)
        while True:
            self.event, self.values = self.windows.Read()
            #When pressing the button, changing the window
            if self.event == 'Safe':
                self.windows.Disappear()
                self.lt2 = [[sg.Button(i)] for i in self.buttons[1]]
                self.windows1 = sg.Window('S').Layout(self.lt2)
                while True:
                    self.event1, self.values1 = self.windows1.Read()
                    if self.event1 == 'Back':
                        self.windows1.close()
                        break
                    if self.event in (None, 'Exit'):
                        break
                self.windows.reappear()
            #Closing part
            if self.event in (None, 'Exit'):
                break

cv = Canvas()
cv.Begin()

【讨论】：