我真的尽了最大的努力自己找到解决方案,但没有。我想从滑块中获得值,然后将其保存为csv文件(它工作得很好),只需单击一个按钮。遗憾的是,在我的按钮事件期间,我无法获取tkinter.Scale
的值。我想知道它的全局变量是否可以解决我的问题,但我还没有让它们工作。我特别惊讶,因为我可以在更改时打印刻度值的实时流,但不能以有用的方式保存它。如果你能回答我的任何困惑,或者让我知道我的问题是否不清楚,或者无论如何可以更好,我将不胜感激。以下是一些帮助我走到这一步的链接:
https://www.programiz.com/python-programming/global-local-nonlocal-variables
Tkinter - Get the name and value of scale/slider
下面是我尝试打印10次最终值的过程:
from tkinter import *
root = Tk()
def scaleevent(v): #Live update of value printed to shell
print(v)
variable = v
def savevalue():
global variable #This is what I want to work, but doesn't
for i in range(10):
print(variable)
scale = Scale(orient='vertical', command=scaleevent).grid(column=0,row=0)
button = Button(text="button", command=savevalue).grid(column=1, row=0)
root.mainloop()
下面是我尝试使用.get()
解决问题的方法
from tkinter import *
root = Tk()
def savevalue(): #print value 10 times. In final version I will save it instead
for i in range(10):
print(scale.get()) #I really want this to work, but it doesn't,
root.destroy #is it because .get is in a function?
scale = Scale(orient='vertical', command=scaleevent).grid(column=0,row=0)
button = Button(text="button", command=savevalue).grid(column=1, row=0)
root.mainloop()
(Python 3.5、Windows 10)
编辑:
这是我第一次尝试使用全局变量时得到的错误:
Exception in Tkinter callback
Traceback (most recent call last):
File "C:\Users\Me\AppData\Local\Programs\Python\Python35\lib\tkinter\__init__.py", line 1550, in __call__
return self.func(*args)
File "C:\Users\Me\Documents\programing\tkinter scale question.py", line 15, in savevalue
print(variable)
NameError: name 'variable' is not defined
这就是当我运行第一个代码示例时发生的事情,与我的实际项目类似。谢谢布莱恩·奥克利!
发布于 2018-06-25 08:01:15
您必须在scaleevent
中使用global
,因为您试图将值传递给variable
。如果没有global
,它会将v
赋值给本地variable
,然后它就不存在于savevalue
中
from tkinter import *
root = Tk()
def scaleevent(v):
global variable
print(v)
variable = v
def savevalue():
print(variable)
Scale(orient='vertical', command=scaleevent).grid(column=0,row=0)
Button(text="button", command=savevalue).grid(column=1, row=0)
root.mainloop()
至于第二个版本,你在var = Widget(...).grid()
上犯了错误
它将None
赋值给var
,因为grid()/pack()/place()
返回None
。
你必须用两行代码来完成:
var = Widget(...)
var.grid(...)
代码
from tkinter import *
root = Tk()
def savevalue():
print(scale.get())
root.destroy() # you forgot ()
scale = Scale(orient='vertical')
scale.grid(column=0,row=0)
button = Button(text="button", command=savevalue)
button.grid(column=1, row=0)
root.mainloop()
发布于 2019-07-24 13:07:42
从tkinter导入*
root = Tk()
variable=0 # only you forgot this
def scaleevent(v):
print(v)
global variable
variable=v
def savevalue():
print(variable)
Scale(orient='vertical', command=scaleevent).grid(column=0,row=0)
Button(text="button", command=savevalue).grid(column=1, row=0)
root.mainloop()
https://stackoverflow.com/questions/51013679
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