用户输入未显示在下一页

Question

我正在编写一个程序，该程序最终会要求用户输入文件名并绘制数据文件的图形。但是，我很难将用户输入文件名转移到下一页。

我已实现此页面 (How to access variables from different classes in tkinter?) 上显示的两个答案，但遗憾的是无法使其正常工作。我在想也许 PageOne 正在被重写，或者 entry_field_variable 正在被重写或未保存。我是 tkinter 的新手，所以我可能会做出明显的疏忽，但感谢您提供任何帮助。

import tkinter as tk


LARGE_FONT= ("Verdana", 12)
NORM_FONT= ("Verdana", 10)
SMALL_FONT= ("Verdana", 8)


class mGui(tk.Tk):  


    def __init__(self, *args, **kargs): 

       tk.Tk.__init__(self, *args, **kargs) 
       container = tk.Frame(self)
       container.grid_rowconfigure(0, weight=1)
       container.grid_columnconfigure(0, weight=1)
       container.grid()



       self.shared_data = {"entry_field_variable":tk.StringVar()}

       self.frames = {}  

       for F in (StartPage, PageOne):

            frame = F(container, self)

            self.frames[F] = frame
            frame.grid(row=0, column=0, sticky="nsew")



       self.show_frame(StartPage)   

    def show_frame(self, cont):  
        frame = self.frames[cont]
        frame.tkraise()   


class StartPage(tk.Frame):  

    def __init__(self, parent, controller):  
        self.controller = controller
        tk.Frame.__init__(self, parent) 
        label_1 = tk.Label(self, text = "Start Page", font = LARGE_FONT)
        label_1.grid(row = 0, column = 0)


        entry1 = tk.Entry(self, textvariable = self.controller.shared_data["entry_field_variable"])
        entry1.grid(row = 1, column = 0)




        button1 = tk.Button(self,text = "Go", command = lambda: controller.show_frame(PageOne))
        button1.grid(row = 2, column = 0) 



class PageOne(tk.Frame):  

    def __init__(self, parent, controller): 
        self.controller = controller
        tk.Frame.__init__(self, parent) 

        label_1 = tk.Label(self, text = "Page One", font = LARGE_FONT)
        label_1.grid(row = 1, column = 4)  

        filename = self.controller.shared_data["entry_field_variable"].get()


        label_2 = tk.Label(self, text = filename, font = LARGE_FONT)
        label_2.grid(row = 2, column = 0)

        button1 = tk.Button(self, text = "Go Back", command = lambda: controller.show_frame(StartPage))
        button1.grid(row = 4, column = 1)              


app = mGui()
app.mainloop()

Answer 1

您使用tk.StringVar 的想法很好，但是您缺少一些东西：

• 您需要收集在StartPage 的entry 字段中输入的值。
• 需要将此值传递给控制器​​。
• 最后，PageOne 必须有权访问它，因此有必要将保存文件名的tk.StringVar 分配给标签textvariable。

这是如何做到的：

import tkinter as tk


LARGE_FONT= ("Verdana", 12)
NORM_FONT= ("Verdana", 10)
SMALL_FONT= ("Verdana", 8)


class mGui(tk.Tk):  

    def __init__(self, *args, **kwargs): 
        tk.Tk.__init__(self, *args, **kwargs) 
        container = tk.Frame(self)
        container.grid_rowconfigure(0, weight=1)
        container.grid_columnconfigure(0, weight=1)
        container.grid()

        self.shared_data = {"filename": tk.StringVar('')}

        self.frames = {}  
        for PageFrame in (StartPage, PageOne):
            frame = PageFrame(container, self)
            self.frames[PageFrame] = frame
            frame.grid(row=0, column=0, sticky="nsew")
        self.show_frame(StartPage)   

    def show_frame(self, cont):  
        frame = self.frames[cont]
        frame.tkraise()   


class StartPage(tk.Frame):  

    def __init__(self, parent, controller):  
        self.controller = controller
        tk.Frame.__init__(self, parent) 
        label_1 = tk.Label(self, text="Start Page", font=LARGE_FONT)
        label_1.grid(row=0, column=0)

        entry1 = tk.Entry(self, textvariable=self.controller.shared_data["filename"])
        entry1.grid(row=1, column=0)

        button1 = tk.Button(self, text="Go", command=lambda: self.controller.show_frame(PageOne))
        button1.grid(row=2, column = 0)


class PageOne(tk.Frame):  

    def __init__(self, parent, controller): 
        self.controller = controller
        tk.Frame.__init__(self, parent) 

        label_1 = tk.Label(self, text="Page One", font=LARGE_FONT)
        label_1.grid(row = 1, column = 4)  

        filename = self.controller.shared_data["filename"]

        label_2 = tk.Label(self, textvariable=filename, font=LARGE_FONT)
        label_2.grid(row = 2, column = 0)

        button1 = tk.Button(self, text="Go Back", command=lambda: self.controller.show_frame(StartPage))
        button1.grid(row=4, column=1)              


app = mGui()
app.mainloop()