Python Tkinter如何将B1运动绑定到组合框
因此,我在一个应用程序中有一个组合框,我要把它放在平板电脑上,这样我就可以拖动组合框,使它向下滚动 到目前为止,我有这个功能:Python Tkinter如何将B1运动绑定到组合框,python,user-interface,tkinter,combobox,Python,User Interface,Tkinter,Combobox,因此,我在一个应用程序中有一个组合框,我要把它放在平板电脑上,这样我就可以拖动组合框,使它向下滚动 到目前为止,我有这个功能: def tablet_drag_y(event): global last_y if event.y_root-last_y>20 or event.y_root-last_y<-20: last_y=event.y_root event.widget.tag_remove(Tk.SEL, "1.0", Tk.
def tablet_drag_y(event):
global last_y
if event.y_root-last_y>20 or event.y_root-last_y<-20:
last_y=event.y_root
event.widget.tag_remove(Tk.SEL, "1.0", Tk.END)
return "break"
event.widget.yview(Tk.SCROLL,-1*(event.y_root-last_y), "units")
last_y=event.y_root
event.widget.tag_remove(Tk.SEL, "1.0", Tk.END)
return "break"
def平板电脑拖动(事件):
全球最后一年
如果event.y_root-last_y>20或event.y_root-last_y您的问题(和解决方案)与。因此,这里的提示和想法也适用于你的问题
首先,像您描述的这样的功能已经存在:当您在列表的边界上移动时,列表会自动滚动。但是好吧,让我们自己来实现一些东西
首先,我们需要理解combobox什么都不是,只是entry和listbox小部件的组合,我们需要一个部分,那就是listbox(一个弹出窗口)。幸运的是,有一种方法可以让你把它撕下来:
popdown = combobox.tk.eval('ttk::combobox::PopdownWindow %s' % combobox)
之后,当我们的组合框映射时,您可以自由地将某些内容绑定到该小部件:
class CustomBox(ttk.Combobox):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.bind('<Map>', self._handle_popdown_bind_on_initialisation)
def _handle_popdown_bind_on_initialisation(self, *args):
popdown = self.tk.eval('ttk::combobox::PopdownWindow %s' % self)
self._bind(('bind', '%s.f.l' % popdown), '<B1-Motion>', <callback_function>, None)
想法很简单:获取一个决策项,即通过列表框的一半,然后根据当前元素的位置决定向上或向下滚动。
class CustomBox(ttk.Combobox):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.bind('<Map>', self._handle_popdown_bind_on_initialisation)
def _handle_popdown_bind_on_initialisation(self, *args):
popdown = self.tk.eval('ttk::combobox::PopdownWindow %s' % self)
self._bind(('bind', '%s.f.l' % popdown), '<B1-Motion>', <callback_function>, None)
import tkinter as tk
import tkinter.ttk as ttk
import random
import string
class CustomBox(ttk.Combobox):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# schedule bind to handle popdown
self.bind('<Map>', self._handle_popdown_bind_on_initialisation)
def _handle_popdown_bind_on_initialisation(self, *args):
# once combobox is drawn bind callback function
popdown = self.tk.eval('ttk::combobox::PopdownWindow %s' % self)
self._bind(('bind', '%s.f.l' % popdown), '<B1-Motion>', drag, None)
def insert_something_to_combobox(box, count=30):
# just to insert some random stuff
box['values'] = [gen_key() for _ in range(count)]
def gen_key(size=6, chars=string.ascii_uppercase + string.digits):
# just to generate some random stuff
return ''.join(random.choice(chars) for _ in range(size))
def drag(event):
# test-event for B1-Motion over popdown
# get index of the nearest item
nearest_item = root.tk.call(event.widget, 'nearest', event.y)
# get actual size of listbox
actual_size = root.tk.call(event.widget, 'size')
# get current boundary positions for listbox
current_yview = root.tk.call(event.widget, 'yview')
# get current boundary items
current_items = [int(fraction * actual_size) for fraction in current_yview]
# get decider-item for scrolling
decider_item = sum(current_items) // 2
# debug-configure current item
mouse_over_label.configure(text='B1 over item: %s' % root.tk.call(event.widget, 'get', nearest_item))
if nearest_item < decider_item:
# scroll-up
root.tk.call(event.widget, 'see', current_items[0] - 1)
elif nearest_item > decider_item:
# scroll-down
root.tk.call(event.widget, 'see', current_items[1] + 1)
root = tk.Tk()
mouse_over_label = tk.Label()
mouse_over_label.pack()
combo_box = CustomBox()
combo_box.pack()
insert_something_to_combobox(combo_box)
root.mainloop()