Question

我正在尝试创建一个Python程序，您可以在其中移动小部件。

这是我的代码：

import tkinter as tk 
main = tk.Tk()
notesFrame = tk.Frame(main, bd = 4, bg = "a6a6a6")
notesFrame.place(x=10,y=10)
notes = tk.Text(notesFrame)
notes.pack()
notesFrame.bind("<B1-Motion>", lambda event: notesFrame.place(x = event.x, y = event.y)

但是，这会出现超级故障并且小部件来回跳跃。

谢谢！

Answer 1

您观察到的行为是由事件的坐标相对于拖动的窗口小部件引起的。使用相对坐标更新窗口小部件的位置（在绝对坐标中）显然会导致混乱。

要解决此问题，我已使用.winfo_x() and .winfo_y()函数（允许将相对坐标转换为绝对坐标）和Button-1事件来确定光标的位置拖动开始时在窗口小部件上。

这是一个使窗口小部件可拖动的功能：

def make_draggable(widget):
    widget.bind("<Button-1>", on_drag_start)
    widget.bind("<B1-Motion>", on_drag_motion)

def on_drag_start(event):
    widget = event.widget
    widget._drag_start_x = event.x
    widget._drag_start_y = event.y

def on_drag_motion(event):
    widget = event.widget
    x = widget.winfo_x() - widget._drag_start_x + event.x
    y = widget.winfo_y() - widget._drag_start_y + event.y
    widget.place(x=x, y=y)

可以像这样使用：

main = tk.Tk()

frame = tk.Frame(main, bd=4, bg="grey")
frame.place(x=10, y=10)
make_draggable(frame)

notes = tk.Text(frame)
notes.pack()

如果你想采用更加面向对象的方法，你可以编写一个mixin来使一个类的所有实例都可以拖动：

class DragDropMixin:
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        make_draggable(self)

用法：

# As always when it comes to mixins, make sure to
# inherit from DragDropMixin FIRST!
class DnDFrame(DragDropMixin, tk.Frame):
    pass

# This wouldn't work:
# class DnDFrame(tk.Frame, DragDropMixin):
#     pass

main = tk.Tk()

frame = DnDFrame(main, bd=4, bg="grey")
frame.place(x=10, y=10)

notes = tk.Text(frame)
notes.pack()

Answer 2

Tkinter有一个模块，记录在模块docstring中。预计它会被tk dnd模块取代，但这种情况并没有发生。我从来没有尝试过。搜索SO [tkinter] dnd会返回this page。下面是docstring的开头。

>>> from tkinter import dnd
>>> help(dnd)
Help on module tkinter.dnd in tkinter:

NAME
    tkinter.dnd - Drag-and-drop support for Tkinter.

DESCRIPTION
    This is very preliminary.  I currently only support dnd *within* one
    application, between different windows (or within the same window).
[snip]

拖放小部件tkinter

2 个答案: