Python 2.7 - Tkinter - 移动到列表框中下一项的按钮

Question

def nextItem(self):
  active = self.skill_list_listbox.get(tk.ACTIVE)
  listbox_contents = self.skill_list_listbox.get(0, tk.END)
  current_pos = listbox_contents.index(active)
  if current_pos + 1 < len(listbox_contents):
    new_pos = current_pos + 1
    self.skill_list_listbox.activate(new_pos)
    self.skill_list_listbox.selection_set(tk.ACTIVE)

根据我在文档中看到的内容，这应该会突出显示并激活列表框中的下一项。如果我省略 selection_set 我会得到我正在寻找的东西，但没有指示什么是活动的。添加它会突出显示一个项目，但如果您继续单击“下一步”按钮，它只会添加到突出显示，而不是仅突出显示一个项目，创建一长段突出显示的项目，这是我不想要的。我尝试了几种不同的方法，这让我最接近。如果有一个“明确的选择”方法，我想我可以得到我想要的效果，即选择并突出显示下一个项目，但是 3 次调用只是为了做这件事对于一项常见的任务来说似乎有点多？有什么想法或建议吗？

Answer 1

以下是我认为您正在尝试完成的示例，使用按钮选择列表框中的下一项。它的要点在于按钮的回调函数，它调用selection_clear，然后调用selection_set。

更新了示例，希望能更清楚地了解它发生了什么

import Tkinter


class Application(Tkinter.Frame):
    def __init__(self, master):
        Tkinter.Frame.__init__(self, master)
        self.master.minsize(width=256, height=256)
        self.master.config()
        self.pack()

        self.main_frame = Tkinter.Frame()

        self.some_list = [
            'One',
            'Two',
            'Three',
            'Four'
        ]

        self.some_listbox = Tkinter.Listbox(self.main_frame)
        self.some_listbox.pack(fill='both', expand=True)
        self.main_frame.pack(fill='both', expand=True)

        # insert our items into the list box
        for i, item in enumerate(self.some_list):
            self.some_listbox.insert(i, item)

        # add a button to select the next item
        self.some_button = Tkinter.Button(
            self.main_frame, text="Next", command=self.next_selection)
        self.some_button.pack(side='top')

        # not really necessary, just make things look nice and centered
        self.main_frame.place(in_=self.master, anchor='c', relx=.5, rely=.5)

    def next_selection(self):
        selection_indices = self.some_listbox.curselection()

        # default next selection is the beginning
        next_selection = 0

        # make sure at least one item is selected
        if len(selection_indices) > 0:
            # Get the last selection, remember they are strings for some reason
            # so convert to int
            last_selection = int(selection_indices[-1])

            # clear current selections
            self.some_listbox.selection_clear(selection_indices)

            # Make sure we're not at the last item
            if last_selection < self.some_listbox.size() - 1:
                next_selection = last_selection + 1

        self.some_listbox.activate(next_selection)
        self.some_listbox.selection_set(next_selection)

root = Tkinter.Tk()
app = Application(root)
app.mainloop()