[英]validating a text entry on tkinter
我正在創建一個程序,該程序允許用戶選擇類別並輸入值以計算費用。 我想使用自己的驗證文件來驗證文本輸入。 但是,當我運行該程序並且在文本輸入中未輸入任何內容時,錯誤窗口不斷反復彈出。 另外,當我運行程序並在輸入字段中輸入有效數字時,即使我已經定義了總費用的計算方式,費用仍為0.0。
這是程序:
import tkinter
import tkinter.messagebox
import ValidationFile
validationObject = ValidationFile.ValidationClass ()
class MyGUI:
def __init__ (self):
self.main_window = tkinter.Tk ()
self.top_frame = tkinter.Frame (self.main_window)
self.middle_frame = tkinter.Frame (self.main_window)
self.bottom_frame = tkinter.Frame (self.main_window)
self.phone_var = tkinter.IntVar ()
self.phone_var.set (1)
self.pb1 = tkinter.Radiobutton (self.top_frame, \
text = 'Daytime (6:00 AM - 5:59 PM)', variable = self.phone_var, \
value = 0.12)
self.pb2 = tkinter.Radiobutton (self.top_frame, \
text = 'Evening (6:00 PM - 11:59 PM)', variable = self.phone_var, \
value = 0.07)
self.pb3 = tkinter.Radiobutton (self.top_frame, \
text = 'Off-Peak (Midnight - 5:50 AM)', variable = self.phone_var, \
value = 0.05)
#pack phone buttons
self.pb1.pack ()
self.pb2.pack ()
self.pb3.pack ()
#create input and output buttons
self.txtInput = tkinter.Entry (self.middle_frame, \
width = 10)
self.value = tkinter.StringVar ()
self.lblOutput = tkinter.Label (self.middle_frame, \
width = 10, textvariable = self.value)
self.txtInput.pack()
self.lblOutput.pack ()
#create OK buton and QUIT button
self.ok_button = tkinter.Button (self.bottom_frame, \
text = 'OK', command = self.show_choice)
self.quit_button = tkinter.Button (self.bottom_frame, \
text = 'QUIT', command = self.main_window.destroy)
#pack the buttons
self.ok_button.pack (side = 'left')
self.quit_button.pack (side = 'left')
#pack the frames
self.top_frame.pack ()
self.middle_frame.pack ()
self.bottom_frame.pack ()
#start the mainloop
tkinter.mainloop ()
def show_choice (self):
choice = self.phone_var.get ()
value = -1
while value == -1:
valueEntry = self.txtInput.get()
if valueEntry == '':
value = -1
tkinter.messagebox.showinfo (title = 'ERROR', \
message = 'Please enter a valid number.')
else:
value = validationObject.checkFloat (valueEntry)
total = choice * value
self.value.set (total)
#create instance of MyGUI class
my_GUI = MyGUI ()
這是驗證文件:
#create validation class
class ValidationClass:
def checkFloat (self, inputString):
try:
result = float (inputString)
except Exception:
return -1
if result < 0:
return -1
else:
return result
def checkInteger (self, inputString):
try:
result = int (inputString)
except Exception:
return -1
if result < 0:
return -1
else:
return result
您使用while value == -1:
進行了無限循環。 您不會在該循環中的任何地方暫停以允許用戶再次嘗試。 您根本不需要循環:
def show_choice (self):
valueEntry = self.txtInput.get()
value = validationObject.checkFloat(valueEntry)
if value == -1:
tkinter.messagebox.showinfo (title = 'ERROR', \
message = 'Please enter a valid number.')
else:
choice = self.phone_var.get()
total = choice * value
self.value.set (total)
修復后,您將遇到另一個問題:您在選項中使用了浮點值,但變量是一個IntVar,它只能處理整數。 因此,“選擇”將始終為0。您需要改用DoubleVar。
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