如果在 Python 中選擇了下拉列表中的項目，則提示用戶輸入

Question

我在 python 中有一個 GUI，除其他外，讓用戶從下拉菜單中選擇項目（我使用了 tkinter 的組合框功能）。

我希望擁有它，以便在選擇“自定義”項時，會出現一個輸入框，詢問用戶他們的自定義編號是什么。 我不想使用按鈕來顯示框，但不知何故，只要選擇自定義，輸入框就會出現。 我首先嘗試使用 while 循環，但無法使其正常工作，與 if 語句相同：s

我還嘗試使用我在這里找到的 askinteger() 方法（ http://effbot.org/tkinterbook/tkinter-entry-dialogs.htm ），但我想出的組合都沒有奏效（我對 Python 和我還在學習所以請原諒我明顯的錯誤）。

這是我的 GUI 代碼：

from tkinter import *
from tkinter.ttk import *
from tkinter import filedialog
from tkinter import StringVar
from tkinter import messagebox
from tkinter import simpledialog


class MyGUI:
    def __init__(self, master):

        self.master = master
        master.title("Intent/Interpretation Check")

        self.runlabel = Label(master, text="RunID :")
        self.runlabel.grid(row=0, column=0)

        self.runentry = Entry(master)
        self.runentry.grid(row=1, column=0, padx=25)

        self.checklabel = Label(master, text="Check type :")
        self.checklabel.grid(row=0, column=1)

        self.typeselect = Combobox(master)
        self.typeselect['values']=("Intent Score", "Interpretation Score")      
        self.typeselect.grid(row=1, column=1, padx=25)

        self.limitlabel = Label(master, text="Fails if score is below :")
        self.limitlabel.grid(row=0, column=2, padx=25)

        self.limitselect = Combobox(master)
        self.limitselect['values']=(1000, 5000, "Custom")       
        self.limitselect.grid(row=1, column=2, padx=25)
        if self.limitselect.get() != "Custom":
            self.limit = self.limitselect.get()
            pass
        else:
            self.askinteger("Custom limit", "Please enter a number from 1 to 10000", minvalue=1, maxvalue=10000)

        self.submitbutton = Button(master, text="Submit", command=self.checkstatus)
        self.submitbutton.grid(row=1, column=3, padx=25, pady=5)

root = Tk()
root.geometry("+600+300")
my_gui = MyGUI(root)
root.mainloop()

非常感謝您提前！

Answer 1

您需要有一個 Bool 來告訴何時應該顯示新輸入。 您還需要不斷輪詢 ComboBox 以查看它的值是否等於“自定義”。 這是我在大約 3 分鍾內想到的。

我沒有試圖讓 GUI 看起來很漂亮，只是一個功能性的例子。

from tkinter import *
from tkinter.ttk import *

class Gui:

    def __init__(self):
        self.root = Tk()

        # Set up the Combobox
        self.selections = Combobox(self.root)
        self.selections['values'] = ['Apples', 'Oranges', 'Blueberries', 'Bananas', 'Custom']
        self.selections.pack()

        # The Entry to be shown if "Custom" is selected
        self.custom_field = Entry(self.root)
        self.show_custom_field = False

        # Check the selection in 100 ms
        self.root.after(100, self.check_for_selection)

    def check_for_selection(self):
        '''Checks if the value of the Combobox equals "Custom".'''


        # Get the value of the Combobox
        value = self.selections.get()

        # If the value is equal to "Custom" and show_field is set to False
        if value == 'Custom' and not self.show_custom_field:

            # Set show_field to True and pack() the custom entry field
            self.show_custom_field = True
            self.custom_field.pack()


        # If the value DOESNT equal "Custom"
        elif value != 'Custom':

            # Set show_field to False
            self.show_custom_field = False

            # Destroy the custom input
            self.custom_field.destroy()

            # Set up a new Entry object to pack() if we need it later.
            # Without this line, tkinter was raising an error for me.
            # This fixed it, but I don't promise that this is the
            # most efficient method to do this.
            self.custom_field = Entry(self.root)

        # If the value IS "Custom" and we're showing the custom_feild
        elif value == 'Custom' and self.show_custom_field:
            pass


        # Call this method again to keep checking the selection box
        self.root.after(100, self.check_for_selection)


app = Gui()
app.root.mainloop()

希望這可以幫助！

編輯：

要打開一個新窗口而不是將其打包在與 Combobox 相同的窗口中，請將函數check_for_selection替換為：

def check_for_selection(self):
    value = self.selections.get()

    # If the value is equal to "Custom" and show_field is set to False
    if value == 'Custom' and not self.show_custom_field:

        # Set show_field to True and pack() the custom entry field
        self.show_custom_field = True

        # Create a new window how we did when we made self.root
        self.new_window = Tk()

        # Create the Entry that will go in the window. The previous Entry widget from line 16, can be removed
        self.custom_field = Entry(self.new_window)
        self.custom_field.pack()

        # Run the new window like we did the original
        self.new_window.mainloop()


    # If the value DOESNT equal "Custom"
    elif value != 'Custom':

        # Destroy the new window that was created if it exists
        if self.show_custom_field:
            self.new_window.destroy()

        # Set show_field to False
        self.show_custom_field = False

    # If the value IS "Custom" and we're showing the custom_feild
    elif value == 'Custom' and self.show_custom_field:
        print('yes')


    # Call this method again to keep checking the selection box
    self.root.after(100, self.check_for_selection)