所以，我用python写了一个小的Tkinter程序。程序运行良好，但如果字段中输入了非数字字符，则很容易发生异常。
所以，我试图补救它，但我的补救措施失败了：
这是问题所在：
try:
self.laborOne = float(self.trimmerOne_Entry.get()) * 8
self.laborTwo = float(self.trimmerTwo_Entry.get()) * 8
self.laborThree = float(self.operator_Entry.get()) * 8
self.addedThem = self.laborOne + self.laborTwo + self.laborThree
self.laborTotal.set(str(self.addedThem))
self.perUnitLabor = self.addedThem / 125
self.laborUnit.set(str(self.perUnitLabor))
except ValueError:
tkinter.messagebox.showinfo('Error:', 'One or more of your values was not numeric. Please fix them.')
self.performIt()
self.performIt()
起初我尝试只在错误处理中显示消息框，但是当您单击确定时会关闭程序。所以，我尝试了递归，将函数调用到自身。发生这种情况时，对话框就停留在那里。因为 self.performIt 不需要传入 arg，所以我将 (self) 传入它只是为了尝试。这允许我在框中修复我的值，这是我正在寻找的，但会导致不同的异常
无论如何，如何在程序不终止的情况下处理 ValueError 异常，以便用户可以输入更正的数据？
完整代码
import tkinter
import tkinter.messagebox
class MyGui:
def __init__(self):
#create the main window widget
self.main_window = tkinter.Tk()
#create 6 frames:
#one for each trimmers/operators pay,
#one for buttons
#one for outputs
self.trimmerOne = tkinter.Frame(self.main_window)
self.trimmerTwo = tkinter.Frame(self.main_window)
self.operator = tkinter.Frame(self.main_window)
self.rotaryLabor = tkinter.Frame(self.main_window)
self.rotaryLaborUnit = tkinter.Frame(self.main_window)
self.buttonFrame = tkinter.Frame(self.main_window)
#create and pack widgets for Trimmer 1
self.trimmerOne_Label = tkinter.Label(self.trimmerOne, text='Enter the payrate for trimmer 1: ')
self.trimmerOne_Entry = tkinter.Entry(self.trimmerOne, width=10)
self.trimmerOne_Label.pack(side='left')
self.trimmerOne_Entry.pack(side='left')
#create and pack widgets for Trimmer 2
self.trimmerTwo_Label = tkinter.Label(self.trimmerTwo, text='Enter the payrate for trimmer 2: ')
self.trimmerTwo_Entry = tkinter.Entry(self.trimmerTwo, width=10)
self.trimmerTwo_Label.pack(side='left')
self.trimmerTwo_Entry.pack(side='left')
#create and pack widgets for Operator
self.operator_Label = tkinter.Label(self.operator, text='Enter the payrate for operator: ')
self.operator_Entry = tkinter.Entry(self.operator, width=10)
self.operator_Label.pack(side='left')
self.operator_Entry.pack(side='left')
#create and pack widgets for rotaryLabor
self.rotaryLabor_Label = tkinter.Label(self.rotaryLabor, text="This is what it cost's in trimmer labor: ")
self.laborTotal = tkinter.StringVar() #to update with laborTotal_Label
self.laborTotal_Label = tkinter.Label(self.rotaryLabor, textvariable=self.laborTotal)
self.rotaryLabor_Label.pack(side='left')
self.laborTotal_Label.pack(side='left')
#create and pack widgets for labor Unit
self.rotaryLaborUnit_Label = tkinter.Label(self.rotaryLaborUnit, text="This is the cost per part in trim labor: ")
self.laborUnit = tkinter.StringVar() #to update with laborTotal_Label
self.laborUnit_Label = tkinter.Label(self.rotaryLaborUnit, textvariable=self.laborUnit)
self.rotaryLaborUnit_Label.pack(side='left')
self.laborUnit_Label.pack(side='left')
#create and pack the button widgets
self.calcButton = tkinter.Button(self.buttonFrame, text = "Calculate", command=self.performIt)
self.saveButton = tkinter.Button(self.buttonFrame, text = "Save", command=self.saveIt)
self.quitButton = tkinter.Button(self.buttonFrame, text = "Quit", command=self.main_window.destroy)
self.calcButton.pack(side="left")
self.saveButton.pack(side="left")
self.quitButton.pack(side="left")
#pack the frames
self.trimmerOne.pack()
self.trimmerTwo.pack()
self.operator.pack()
self.rotaryLabor.pack()
self.rotaryLaborUnit.pack()
self.buttonFrame.pack()
tkinter.mainloop()
#define the function that will do the work:
def performIt(self):
try:
self.laborOne = float(self.trimmerOne_Entry.get()) * 8
self.laborTwo = float(self.trimmerTwo_Entry.get()) * 8
self.laborThree = float(self.operator_Entry.get()) * 8
self.addedThem = self.laborOne + self.laborTwo + self.laborThree
self.laborTotal.set(str(self.addedThem))
self.perUnitLabor = self.addedThem / 125
self.laborUnit.set(str(self.perUnitLabor))
except ValueError:
tkinter.messagebox.showinfo('Error:', 'One or more of your values was not numeric. Please fix them.')
self.performIt()
self.performIt()
def saveIt(self):
self.laborOne = float(self.trimmerOne_Entry.get()) * 8
self.laborTwo = float(self.trimmerTwo_Entry.get()) * 8
self.laborThree = float(self.operator_Entry.get()) * 8
self.addedThem = self.laborOne + self.laborTwo + self.laborThree
self.laborTotal.set(str(self.addedThem))
self.perUnitLabor = self.addedThem / 125
self.laborUnit.set(str(self.perUnitLabor))
file = open("log.txt", 'w')
file.write("Trimmer One gets paid: " + str(self.laborOne))
file.write("\n___________________________________________\n")
file.write("Trimmer Two gets paid: " + str(self.laborTwo))
file.write("\n___________________________________________\n")
file.write("Operator gets paid: " + str(self.laborThree))
file.write("\n___________________________________________\n")
file.write("The sum of thier daily labor is: " + str(self.addedThem))
file.write("\n___________________________________________\n")
file.write("If production is reached, the labor cost is" + str(self.laborOne) + "per unit")
file.write("\n___________________________________________\n")
file.close()
testRun = MyGui()