Question

我试图切片，现在我的标签不会显示..

首先我得到一个具有默认浮点值的DoubleVar。然后我尝试将更新后的值转换为字符串，然后对其进行切片并将值设置为标签，其结果来自条目和OptionsMenu。

我试图实现的是始终在resultlabel1中获得一个带有3位小数的值，当条目和OptionsMenu更改时会更新。

我正在谈论的代码：

self.resultlabel1 = DoubleVar()
self.resultlabel1.set(float(0.000))

self.label1 = Label(root, textvariable=str(self.resultlabel1)[:5])
self.label1.grid(row=2, column=3, columnspan=1, sticky='WE')

我的总代码在这里：

from tkinter import *
from decimal import *

class App(Frame):
    def __init__(self, root=None):
        Frame.__init__(self, root)

        self.materialPrice = {'Brick': 70, 'Rockwool': 50, 'Concrete': 20}

        materialvariable1 = StringVar(self, root)
        materialvariable1.set("Choose material")
        materialvariable2 = StringVar(self, root)
        materialvariable2.set("Choose materiale")

        self.w1 = OptionMenu(root, materialvariable1, *self.materialPrice, command=self.displayPrice)
        self.w1.grid(row=2, column=0, columnspan=1, sticky='WE')

        self.w2 = OptionMenu(root, materialvariable2, *self.materialPrice, command=self.displayPrice2)
        self.w2.grid(row=3, column=0, columnspan=1, sticky='WE')
# --------------------------------------------------------------------------------------------------------------------
        self.var = DoubleVar()
        self.var.set(Decimal("0.100"))
        self.var2 = DoubleVar()
        self.var2.set(Decimal("0.200"))

        self.entry1 = Entry(root, textvariable=self.var)
        self.entry1.grid(row=2, column=1)
        self.entry2 = Entry(root, textvariable=self.var2)
        self.entry2.grid(row=3, column=1)
# --------------------------------------------------------------------------------------------------------------------
        self.priceVarLabel1 = DoubleVar()
        self.priceVarLabel1.set(float(0.00))
        self.priceVarLabel2 = DoubleVar()
        self.priceVarLabel2.set(float(0.00))

        self.priceVarValue1 = Label(root, textvariable=self.priceVarLabel1, relief='sunken')
        self.priceVarValue1.grid(row=2, column=2, columnspan=1, sticky='WE')
        self.priceVarValue2 = Label(root, textvariable=self.priceVarLabel2, relief='sunken')
        self.priceVarValue2.grid(row=3, column=2, columnspan=1, sticky='WE')

        self.resultlabel1 = DoubleVar()
        self.resultlabel1.set(float(0.000))
        self.resultlabel2 = DoubleVar()
        self.resultlabel2.set(float(0.00))

# This is what I got so far!
        self.label1 = Label(root, textvariable=str(self.resultlabel1)[:5])
        self.label1.grid(row=2, column=3, columnspan=1, sticky='WE')

        self.label2 = Label(root, textvariable=self.resultlabel2)
        self.label2.grid(row=3, column=3, columnspan=1, sticky='WE')

# --------------------------------------------------------------------------------------------------------------------
        self.resultSumNew = DoubleVar()
        #self.resultSumNew.set(float(0.00))
        self.resultSumNew.set(Decimal("0.000"))
        self.labelSum = Label(root, textvariable=self.resultSumNew)
        self.labelSum.grid(row=4, column=1, columnspan=1, sticky='WE')

        def set_label(name, index, mode):
            self.resultSumNew.set(self.var.get() + self.var2.get())

        self.var.trace('w', set_label)
        self.var2.trace('w', set_label)

# --------------------------------------------------------------------------------------------------------------------

    def displayPrice(self, value):
        self.resultlabel1.set(self.var.get() / self.materialPrice[value])
        self.priceVarLabel1.set(self.materialPrice[value])                                                              

    def displayPrice2(self, value):
        self.resultlabel2.set(self.var2.get() / self.materialPrice[value])
        self.priceVarLabel2.set(self.materialPrice[value])



root = Tk()
app = App(root)
root.title("help")
root.mainloop()

Answer 1

我能够这样做。将StringVar用于标签文本，然后将其切片

self.resultlabel1 = DoubleVar()
self.resultlabel1.set(float(0.000))
self.resultlabel2 = DoubleVar()
self.resultlabel2.set(float(0.00))

self.resultlabel1_str = StringVar()
self.resultlabel1_str.set(str(self.resultlabel1.get()))

self.label1 = Label(root, textvariable=self.resultlabel1_str)
self.label1.grid(row=2, column=3, columnspan=1, sticky='WE')

self.label2 = Label(root, textvariable=self.resultlabel2)
self.label2.grid(row=3, column=3, columnspan=1, sticky='WE')

在你的职能中，

def displayPrice(self, value):
    self.resultlabel1.set(self.var.get() / self.materialPrice[value])
    self.priceVarLabel1.set(self.materialPrice[value])   
    self.resultlabel1_str.set(str(self.resultlabel1.get())[:5])                                                           

def displayPrice2(self, value):
    self.resultlabel2.set(self.var2.get() / self.materialPrice[value])
    self.priceVarLabel2.set(self.materialPrice[value])

希望这有帮助。

切片并将其设置为标签，现在标签未显示

1 个答案: