按键切换界面

Question

我是 Tkinter 的新手，我想创建一个按钮，按下该按钮会显示第二个界面。我编写了以下程序：

import Tkinter

root = Tkinter.Tk(  )
root.title("My First Game")

for r in range(3):
    for c in range(3):
            Tkinter.Label(root, text= '3', borderwidth=20 ).grid(row=1,column=1)
        Tkinter.Label(root, text= '6', borderwidth=20 ).grid(row=1,column=2)
        Tkinter.Label(root, text= '4', borderwidth=20 ).grid(row=1,column=3)
        Tkinter.Label(root, text= '2', borderwidth=20 ).grid(row=2,column=1)
        Tkinter.Label(root, text= '7', borderwidth=20 ).grid(row=2,column=2)
        Tkinter.Label(root, text= ' ', borderwidth=20 ).grid(row=2,column=3)
        Tkinter.Label(root, text= '5', borderwidth=20 ).grid(row=3,column=1)
        Tkinter.Label(root, text= '1', borderwidth=20 ).grid(row=3,column=2)
        Tkinter.Label(root, text= '8', borderwidth=20 ).grid(row=3,column=3)

def mainprg():
    for r in range(3):
        for c in range(3):
            Tkinter.Label(root, text= '3', borderwidth=20 ).grid(row=1,column=1)
            Tkinter.Label(root, text= '6', borderwidth=20 ).grid(row=1,column=2)
            Tkinter.Label(root, text= ' ', borderwidth=20 ).grid(row=1,column=3)
            Tkinter.Label(root, text= '2', borderwidth=20 ).grid(row=2,column=1)
            Tkinter.Label(root, text= '7', borderwidth=20 ).grid(row=2,column=2)
            Tkinter.Label(root, text= '4', borderwidth=20 ).grid(row=2,column=3)
            Tkinter.Label(root, text= '5', borderwidth=20 ).grid(row=3,column=1)
            Tkinter.Label(root, text= '1', borderwidth=20 ).grid(row=3,column=2)
            Tkinter.Label(root, text= '8', borderwidth=20 ).grid(row=3,column=3)


B = Tkinter.Button(text = "Run", command = mainprg)
B.pack()

root.mainloop()

我正在尝试显示第一个界面和 Run 按钮。按下 Run 按钮后，将显示第二个界面。但是运行上面的代码后，什么都没有显示。

Answer 1

这是一个示例，它可以成为您尝试做的事情的一部分。请注意使用必须替换的标签的引用列表。如果没有使用clean 方法，那么您只需“覆盖”之前的屏幕外观，这可能会导致界面损坏，部分按钮可见，部分被其他对象恢复。

import Tkinter as Tki

#constants - using this you can eventually change the interface's language by importing a different file containning these values.
__title__ = "my first program"
__run__ = "run!"

#widgets contain all the currently created widgets, this will alow to destroy and replace them.
global widgets
widgets = []

#---------------------------------------------------------------------------------------------------
def clean():
    for widget in widgets:
        widget.grid_remove()
        widget.destroy()
#---------------------------------------------------------------------------------------------------
def createMainButton(master):
    clean()
    #it is required to specify the master, i.e. the container of each new widget as first parameter
    button = Tki.Button(root, text = __run__, command = lambda : mainProg(root))
    button.grid(row=0, column=0)
    #have to provide a reference to the widget to allow clean destroy of it.
    widgets.append(button)
#---------------------------------------------------------------------------------------------------
def mainProg(master):
    clean()
    #define a subclass
    def create (content, row, column):
        createLabel(master, content , 20, row , column)
    #create widgets
    create('3', 1, 1)
    create('6', 1, 2)
    create('4', 1, 3)
    create('2', 2, 1)
    create('7', 2, 2)
    create(' ', 2, 3)
    create('5', 3, 1)
    create('1', 3, 2)
    create('8', 3, 3)
#---------------------------------------------------------------------------------------------------

def createLabel(master, content, borderSize, row, column):
    label = Tki.Label(master, text= content, borderwidth=borderSize )
    label.grid(row=row,column=column)
    widgets.append(label)

if __name__ == "__main__":

    root = Tki.Tk()
    root.title(__title__)

    createMainButton(root)  

    root.mainloop()

我不知道您对对象编程有什么了解，但请考虑另一种方法来实现您的目标：扩展 Tk 类以便在不定义全局变量的情况下提供对特定范围内所需数据的访问（即一般来说，不好！）。我个人会这样编码：

import Tkinter as Tki

#constants - using this you can eventually change the interface's language by importing a different file containning these values.
__title__ = "my first program"
__run__ = "run!"

class MyProgram(Tki.Tk):
    def __init__(self):
        Tki.Tk.__init__(self)

        self.widgets = []
        self.CONSTANT_BORDERWIDTH = 20

        self.title(__title__)       
        self.createMainButton()

    def clean(self):
        for widget in self.widgets:
            widget.grid_remove()
            widget.destroy()    

    def createMainButton(self):
        self.clean()
        #it is required to specify the master, i.e. the container of each new widget as first parameter
        button = Tki.Button(self, text = __run__, command = self.mainProg)
        button.grid(row=0, column=0)
        #have to provide a reference to the widget to allow clean destroy of it.
        self.widgets.append(button)

    def mainProg(self):
        self.clean()
        #create widgets
        self.createLabel('3', 1, 1)
        self.createLabel('6', 1, 2)
        self.createLabel('4', 1, 3)
        self.createLabel('2', 2, 1)
        self.createLabel('7', 2, 2)
        self.createLabel(' ', 2, 3)
        self.createLabel('5', 3, 1)
        self.createLabel('1', 3, 2)
        self.createLabel('8', 3, 3)

    def createLabel(self,content, row, column):
        label = Tki.Label(self, text= content, borderwidth=self.CONSTANT_BORDERWIDTH )
        label.grid(row=row,column=column)
        self.widgets.append(label)

if __name__ == "__main__":
    root = MyProgram()
    root.mainloop()

不管怎样，如果这段代码太难理解，就暂时忘记对象编程吧。

祝你好运！ 亚瑟。

Answer 2

您正在混合grid 和pack（这是一个坏主意，请参阅例如https://stackoverflow.com/a/3968033/3001761）；将B的赋值改为：

B = Tkinter.Button(text = "Run", command = mainprg)
B.grid(row=4, column=1)

此外，您的 for 循环无缘无故地做了 9 次相同的事情；您可能应该重新考虑逻辑。