Question

我无法让tkinter更新一对简单的“应用程序全局”布尔变量来匹配相关复选框的变量。布尔值被初始化，更新并存储在一个文件中，并由另一个文件引用（只读）。无论复选框状态如何，布尔值都不会从默认值更改。（值得注意的一点：False / True的初始值变为0/1，可能是由于tkinter forlelements booleans有问题）。奇怪的是，对应于tkinter复选框表的类似“应用程序全局”布尔表没有问题。该表是由第三个文件定义的类的实例。该表与简单的布尔值位于同一个文件中（并以相同的方式处理）所有布尔值都在一个文件（File1.py）中使用（只读），并且只由另一个文件（File2.py）修改。显式返回问题布尔值（从File2.py到File1.py）不起作用。

正在使用的环境是带有Pydev 2.7.32013031601插件的Eclipse Juno（4.2.2，build M20130204-1200）上的Windows 7，Python 3.2.2。该应用程序正在从Eclipse控制台运行。

通过LEGB范围规则，一切似乎都正常（包含和全局语句存在，虚线名称形式用于外部定义的“应用程序级”全局变量）。在我看来，要么所有布尔更新都应该工作，要么都不应该工作。那么为什么布尔表工作正常而不是简单的布尔值 - 以及让简单的布尔值正常工作需要什么呢？
推测，它可能与python实现具有基本值（例如0,1,2,3，True？False？）的变量作为“共享值”而不是单独变量的方式有关 - 这会导致引用时出现问题这些来自其他模块的简单值？

示例应用程序包含3个文件;每个都尽可能减少，同时仍然能够显示问题。在Windows 7上运行时，您应该看到： Tkinter window sowing rusluts of running sample code

File1.py - mainline，包含回调函数“Get_User_Selections”：

from tkinter  import *
from tkinter  import ttk
import File2 
#==========================================================================
def Get_User_Selections( ):

    print( "\nDoAllReports=", File2.DoAllReports, "DoNoReports=", File2.DoNoReports )

    if ( not File2.DoNoReports ) :  
        for row in range( len( File2.ChosenReports ) ):
            for column in range( len( File2.ChosenReports[ 0 ] ) ) :              
                if ( File2.ChosenReports[ row ][ column ].get() or
                     File2.DoAllReports ) :

                    print( "Do report  (", row, ',', column, ')' )               
    return
#==========================================================================         
def CreateTheReports( *args ):
    Get_User_Selections( )
    return
#==========================================================================
''' *********** MAIN PROCEDURE ***************** '''
root = Tk()
root.title( 'tkinter Boolean problem' )

mainframe = ttk.Frame( root )
mainframe.grid( )

File2.ChooseReports( mainframe )

DoItButton  = Button( mainframe, text = 'DO IT!', command = CreateTheReports )
DoItButton.grid()

root.mainloop()      
#==========================================================================

File2.py - 定义GUI，更新所有“应用程序级全局”布尔值：

from tkinter  import *

# import the custom "GUI table" widgit class (which works as expected)

from TkinterCheckBoxTableClass import TkinterCheckBoxTableClass

# Determine the table "shape" (in the original application the strings become  
# the row and column headers, these headers NOT shown by this example code).

RowTitles    = [ "A", "B" ] 
ColumnTitles = [ "1", "2", "3", "4" ]

DefaultReports = [ ]
for i in RowTitles :
    for j in ColumnTitles :
        DefaultReports = DefaultReports + [ False ] 

# Initialize the three "APPLICATION LEVEL" global variables that preserve the
# user choices across invocations of the routine.  Each invocation is caused
# by the user pressing the "DO IT!" button on the GUI.

ChosenReports = DefaultReports     # table of user choices (works properly)

# These two "application" globals override the table (above) of individual 
# choices.  "DoNoReports" overrides "DoAllReports"; both override the table. 

DoAllReports  = False    # does not work, value never changes    
DoNoReports   = False    # does not work, value never changes    

#==========================================================================
def ChooseReports( ParentFrame ):    
    # Purpose : Interface between the "application globals" and what appears
    #           on the GUI.  Called from File1.py whenever user presses 
    #           the "DO IT" button

    global ChosenReports   # "application" global, resides in this file
    global DoAllReports    # "application" global, resides in this file
    global DoNoReports     # "application" global, resides in this file

    GuiTable = [ [ IntVar() for j in range( len( ColumnTitles ) ) ]
                                        for i in range( len( RowTitles ) ) ]

    ThisFrame = LabelFrame( ParentFrame, text = " Select Reports " )    
    ThisFrame.grid( row = 1, column = 0 )

    DoAll  = IntVar( value = DoAllReports )
    DoNone = IntVar( value = DoNoReports )

    SelectAll = Checkbutton( ThisFrame, variable = DoAll, text = "All",
                             onvalue = True, offvalue = False)
    SelectAll.grid( row = 0, column = 1 )

    SelectNone = Checkbutton( ThisFrame, variable = DoNone, text ='None',
                              onvalue = True, offvalue = False )
    SelectNone.grid( row = 0, column = 2 )

    TableFrame = LabelFrame( ThisFrame, background = 'grey', 
                             borderwidth = 1, relief = FLAT )
    TableFrame.grid( row = 1, column = 0, columnspan = 3, rowspan = 2 )

    # Create the custom Checkbox Table, works without any problems.

    ChooseTheReports =  TkinterCheckBoxTableClass( FrameID = TableFrame,
                                              UserSelections = GuiTable )
    # Update the "application level" globals
    DoAllReports  = DoAll.get( )
    DoNoReports   = DoNone.get( )
    ChosenReports = ChooseTheReports.getTable( )
    # Passing back the above variables in the return statement did NOT work.
    # Returning them shouldn't even be needed since a) they have "application" 
    # level scope, b) they reside in THIS file and c) are ONLY modified by THIS 
    # file (with the new values being accessible from other files).   
    return  

#==========================================================================

TkinterCheckBoxTableClass.py - 实现布尔表：

'''
Implements a 2-D matrix (table) of tkinter checkboxes (for Python 3.x).
'''
from tkinter import *
from tkinter import ttk

class TkinterCheckBoxTableClass( object ):   
    '''
    Python 3.x interface to a matrix (2-D table) of tkinter checkboxes.
    Must pass a tkinter frame and the matrix to the constructor.
    Class constructor parameters:    
        FrameID             - tkinter parent frame that displays the table
        UserSelections      - matrix of True/False values passed to/from to GUI         
    Entire Table Methods:    
        getTable()         - extracts 2-D array of UserSelections from tkinter
    '''
    '''----------------------------------------------------------------------'''
    '''
    Constructor
    '''   
    def __init__( self , FrameID, UserSelections ) :               
        self.frameID             = FrameID      
        self.userSelections      = UserSelections       
        self.rowCount            = max( 1, len( self.userSelections ) )
        self.columnCount         = max( 1, len( self.userSelections[ 0 ] ) )                              
        self.checkBoxTable  = [ [ IntVar() for j in range( self.columnCount ) ]
                                           for i in range( self.rowCount ) ]
        # Construct and display the table of tkinter checkboxes
        for i in range( self.rowCount ) :
            for j in range( self.columnCount ) :
                self.checkBoxTable[i][j] = Checkbutton( self.frameID,
                                    variable = self.userSelections[ i ][ j ],
                                    onvalue  = True, offvalue = False )
                self.checkBoxTable[i][j].grid( row =  i + 1, column =  j + 1, 
                                               sticky = W )
    '''----------------------------------------------------------------------'''
    '''Methods:'''    
    def getTable( self ) :
        for i in range( self.rowCount ) :
            for j in range( self.columnCount ) :
                self.checkBoxTable[i][j] = Checkbutton( self.frameID,
                                     variable = self.userSelections[ i ][ j ],
                                     onvalue  = True,offvalue = False )
                self.checkBoxTable[i][j].grid( row = i + 1, column = j + 1,
                                               sticky = W )
        return self.userSelections   
''' END CLASS '''

顺便说一句，关于PEP8：请参阅PEP8介绍后的部分。 ;＆gt;）我也很清楚“应用程序全局”和kludgey“创建一个通用的包含文件并将其导入到任何地方”的方法的优点/缺点;一个我不想使用的，除非绝对没有其他简单的方法来解决我的问题。（我更喜欢只在需要的地方导入模块。）

Answer 1

只需定义DoAllReports和DoNoReports，就像这样：

DoAllReports = IntVar(False)

然后在您的客户端代码中，使用DoAllReports.get()代替DoAllReports，DoNoReports使用IntVars。不要创建单独的DoAll DoNone和DoAllReports;它们不是必需的，只需使用DoNoReports和DoAllReports = DoAll.get() DoNoReports = DoNone.get()。

这些行没有做任何事情的原因：

IntVars

...是在构建对话框之前执行，然后用户才有机会点击他们所附加的按钮。因此，您只需返回刚刚初始化DO IT!的相同值。您不会在任何其他时间更新您的全局变量，例如当用户点击{{1}}时，它们自然不会更新。

Answer 2

在创建gui时，您似乎只设置了这些全局变量的值。一旦gui出现并允许用户与支票按钮交互，我看不到代码会改变它们的值。仅仅因为使用DoAll.get()的结果初始化它们并不意味着在检查检查按钮时它们会继续更新。

为什么需要这些变量？当用户点击一个checkbutton时，您已经创建了做更新的IntVar，为什么要添加另一个抽象级别？只要您需要值，就可以使用DoAll.get()。

表的工作原因是因为它是IntVar的表，当checkbutton值发生变化时会不断更新。

tkinter不会更新布尔值 - 但会更新布尔值

2 个答案: