我正在尝试使用 Tkinter 在 Python 中实现可滚动框架：
我很惊讶运行这个功能似乎有多困难，因为它似乎是一个非常基本的功能。 前三个要求看起来相对简单，但自从尝试填充小部件以来我遇到了很多麻烦。
以下实现存在以下问题：
我做错了什么？ 任何帮助将不胜感激。
#!/usr/bin/env python
# based on https://stackoverflow.com/q/30018148
try:
import Tkinter as tk
except:
import tkinter as tk
# I am not using something like vars(tk.Grid) because that would override too many methods.
# Methods like Grid.columnconfigure are suppossed to be executed on self, not a child.
GM_METHODS_TO_BE_CALLED_ON_CHILD = (
'pack', 'pack_configure', 'pack_forget', 'pack_info',
'grid', 'grid_configure', 'grid_forget', 'grid_remove', 'grid_info',
'place', 'place_configure', 'place_forget', 'place_info',
)
class AutoScrollbar(tk.Scrollbar):
'''
A scrollbar that hides itself if it's not needed.
Only works if you use the grid geometry manager.
'''
def set(self, lo, hi):
if float(lo) <= 0.0 and float(hi) >= 1.0:
self.grid_remove()
else:
self.grid()
tk.Scrollbar.set(self, lo, hi)
def pack(self, *args, **kwargs):
raise TclError('Cannot use pack with this widget.')
def place(self, *args, **kwargs):
raise TclError('Cannot use place with this widget.')
#TODO: first time a scrollbar appears, frame does not fill canvas (seems to depend on available space)
#TODO: size jumps: add elements until horizontal scrollbar becomes visible. make widget wider. height jumps from 276 to 316 pixels although it should stay constant.
#TODO: infinite loop is triggered by
# - add rows until the vertical scrollbar appears, remove one row so that vertical scrollbar disappears again, add one row again (depends on size)
# was in the past triggered by:
# - clicking "add row" very fast at transition from no vertical scrollbar to vertical scrollbar visible
# - add columns until horizontal scrollbar appears, remove column so that horizointal scrollbar disappears again, add rows until vertical scrollbar should appear
class ScrollableFrame(tk.Frame):
def __init__(self, master, *args, **kwargs):
self._parentFrame = tk.Frame(master)
self._parentFrame.grid_rowconfigure(0, weight = 1)
self._parentFrame.grid_columnconfigure(0, weight = 1)
# scrollbars
hscrollbar = AutoScrollbar(self._parentFrame, orient = tk.HORIZONTAL)
hscrollbar.grid(row = 1, column = 0, sticky = tk.EW)
vscrollbar = AutoScrollbar(self._parentFrame, orient = tk.VERTICAL)
vscrollbar.grid(row = 0, column = 1, sticky = tk.NS)
# canvas & scrolling
self.canvas = tk.Canvas(self._parentFrame,
xscrollcommand = hscrollbar.set,
yscrollcommand = vscrollbar.set,
bg = 'red', # should not be visible
)
self.canvas.grid(row = 0, column = 0, sticky = tk.NSEW)
hscrollbar.config(command = self.canvas.xview)
vscrollbar.config(command = self.canvas.yview)
# self
tk.Frame.__init__(self, self.canvas, *args, **kwargs)
self._selfItemID = self.canvas.create_window(0, 0, window = self, anchor = tk.NW)
# bindings
self.canvas.bind('<Enter>', self._bindMousewheel)
self.canvas.bind('<Leave>', self._unbindMousewheel)
self.canvas.bind('<Configure>', self._onCanvasConfigure)
# geometry manager
for method in GM_METHODS_TO_BE_CALLED_ON_CHILD:
setattr(self, method, getattr(self._parentFrame, method))
def _bindMousewheel(self, event):
# Windows
self.bind_all('<MouseWheel>', self._onMousewheel)
# Linux
self.bind_all('<Button-4>', self._onMousewheel)
self.bind_all('<Button-5>', self._onMousewheel)
def _unbindMousewheel(self, event):
# Windows
self.unbind_all('<MouseWheel>')
# Linux
self.unbind_all('<Button-4>')
self.unbind_all('<Button-5>')
def _onMousewheel(self, event):
if event.delta < 0 or event.num == 5:
dy = +1
elif event.delta > 0 or event.num == 4:
dy = -1
else:
assert False
if (dy < 0 and self.canvas.yview()[0] > 0.0) \
or (dy > 0 and self.canvas.yview()[1] < 1.0):
self.canvas.yview_scroll(dy, tk.UNITS)
return 'break'
def _onCanvasConfigure(self, event):
self._updateSize(event.width, event.height)
def _updateSize(self, canvWidth, canvHeight):
hasChanged = False
requWidth = self.winfo_reqwidth()
newWidth = max(canvWidth, requWidth)
if newWidth != self.winfo_width():
hasChanged = True
requHeight = self.winfo_reqheight()
newHeight = max(canvHeight, requHeight)
if newHeight != self.winfo_height():
hasChanged = True
if hasChanged:
print("update size ({width}, {height})".format(width = newWidth, height = newHeight))
self.canvas.itemconfig(self._selfItemID, width = newWidth, height = newHeight)
return True
return False
def _updateScrollregion(self):
bbox = (0,0, self.winfo_reqwidth(), self.winfo_reqheight())
print("updateScrollregion%s" % (bbox,))
self.canvas.config( scrollregion = bbox )
def updateScrollregion(self):
# a function called with self.bind('<Configure>', ...) is called when resized or scrolled but *not* when widgets are added or removed (is called when real widget size changes but not when required/requested widget size changes)
# => useless for calling this function
# => this function must be called manually when adding or removing children
# The content has changed.
# Therefore I need to adapt the size of self.
# I need to update before measuring the size.
# It does not seem to make a difference whether I use update_idletasks() or update().
# Therefore according to Bryan Oakley I better use update_idletasks https://stackoverflow.com/a/29159152
self.update_idletasks()
self._updateSize(self.canvas.winfo_width(), self.canvas.winfo_height())
# update scrollregion
self._updateScrollregion()
def setWidth(self, width):
print("setWidth(%s)" % width)
self.canvas.configure( width = width )
def setHeight(self, height):
print("setHeight(%s)" % width)
self.canvas.configure( height = height )
def setSize(self, width, height):
print("setSize(%sx%s)" % (width, height))
self.canvas.configure( width = width, height = height )
# ==================== TEST ====================
if __name__ == '__main__':
class Test(object):
BG_COLOR = 'white'
PAD_X = 1
PAD_Y = PAD_X
# ---------- initialization ----------
def __init__(self):
self.root = tk.Tk()
self.buttonFrame = tk.Frame(self.root)
self.buttonFrame.pack(side=tk.TOP)
self.scrollableFrame = ScrollableFrame(self.root, bg=self.BG_COLOR)
self.scrollableFrame.pack(side=tk.TOP, expand=tk.YES, fill=tk.BOTH)
self.scrollableFrame.grid_columnconfigure(0, weight=1)
self.scrollableFrame.grid_rowconfigure(0, weight=1)
self.contentFrame = tk.Frame(self.scrollableFrame, bg=self.BG_COLOR)
self.contentFrame.grid(row=0, column=0, sticky=tk.NSEW)
self.labelRight = tk.Label(self.scrollableFrame, bg=self.BG_COLOR, text="right")
self.labelRight.grid(row=0, column=1)
self.labelBottom = tk.Label(self.scrollableFrame, bg=self.BG_COLOR, text="bottom")
self.labelBottom.grid(row=1, column=0)
tk.Button(self.buttonFrame, text="add row", command=self.addRow).grid(row=0, column=0)
tk.Button(self.buttonFrame, text="remove row", command=self.removeRow).grid(row=1, column=0)
tk.Button(self.buttonFrame, text="add column", command=self.addColumn).grid(row=0, column=1)
tk.Button(self.buttonFrame, text="remove column", command=self.removeColumn).grid(row=1, column=1)
self.row = 0
self.col = 0
def start(self):
self.addRow()
widget = self.contentFrame.grid_slaves()[0]
width = widget.winfo_width() + 2*self.PAD_X + self.labelRight.winfo_width()
height = 4.9*( widget.winfo_height() + 2*self.PAD_Y ) + self.labelBottom.winfo_height()
#TODO: why is size saved in event different from what I specify here?
self.scrollableFrame.setSize(width, height)
# ---------- add ----------
def addRow(self):
if self.col == 0:
self.col = 1
columns = self.col
for col in range(columns):
button = self.addButton(self.row, col)
self.row += 1
self._onChange()
def addColumn(self):
if self.row == 0:
self.row = 1
rows = self.row
for row in range(rows):
button = self.addButton(row, self.col)
self.col += 1
self._onChange()
def addButton(self, row, col):
button = tk.Button(self.contentFrame, text = '--------------------- %d, %d ---------------------' % (row, col))
# note that grid(padx) seems to behave differently from grid_columnconfigure(pad):
# grid : padx = "Optional horizontal padding to place around the widget in a cell."
# grid_rowconfigure: pad = "Padding to add to the size of the largest widget in the row when setting the size of the whole row."
# http://effbot.org/tkinterbook/grid.htm
button.grid(row=row, column=col, sticky=tk.NSEW, padx=self.PAD_X, pady=self.PAD_Y)
# ---------- remove ----------
def removeRow(self):
if self.row <= 0:
return
self.row -= 1
columns = self.col
if columns == 0:
return
for button in self.contentFrame.grid_slaves():
info = button.grid_info()
if info['row'] == self.row:
button.destroy()
self._onChange()
def removeColumn(self):
if self.col <= 0:
return
self.col -= 1
rows = self.row
if rows == 0:
return
for button in self.contentFrame.grid_slaves():
info = button.grid_info()
if info['column'] == self.col:
button.destroy()
self._onChange()
# ---------- other ----------
def _onChange(self):
print("=========== user action ==========")
print("new size: %s x %s" % (self.row, self.col))
self.scrollableFrame.updateScrollregion()
def mainloop(self):
self.root.mainloop()
test = Test()
test.start()
test.mainloop()
编辑：我不认为这与这个问题重复。如果您不知道如何开始，那么这个问题的答案无疑是一个很好的起点。它解释了如何在 Tkinter 中处理滚动条的基本概念。然而，这不是我的问题。我认为我了解基本想法，并且我认为我已经实现了它。
我注意到答案提到了直接在画布上绘图而不是在其上放置框架的可能性。但是，我想要一个可重复使用的解决方案。
我的问题是，当我尝试实现内容应填充框架（如
pack(expand=tk.YES, fill=tk.BOTH)编辑2：我进一步减少了代码：
# based on https://stackoverflow.com/q/30018148
try:
import Tkinter as tk
except:
import tkinter as tk
class AutoScrollbar(tk.Scrollbar):
def set(self, lo, hi):
if float(lo) <= 0.0 and float(hi) >= 1.0:
self.grid_remove()
else:
self.grid()
tk.Scrollbar.set(self, lo, hi)
class ScrollableFrame(tk.Frame):
# ---------- initialization ----------
def __init__(self, master, *args, **kwargs):
self._parentFrame = tk.Frame(master)
self._parentFrame.grid_rowconfigure(0, weight = 1)
self._parentFrame.grid_columnconfigure(0, weight = 1)
# scrollbars
hscrollbar = AutoScrollbar(self._parentFrame, orient = tk.HORIZONTAL)
hscrollbar.grid(row = 1, column = 0, sticky = tk.EW)
vscrollbar = AutoScrollbar(self._parentFrame, orient = tk.VERTICAL)
vscrollbar.grid(row = 0, column = 1, sticky = tk.NS)
# canvas & scrolling
self.canvas = tk.Canvas(self._parentFrame,
xscrollcommand = hscrollbar.set,
yscrollcommand = vscrollbar.set,
bg = 'red', # should not be visible
)
self.canvas.grid(row = 0, column = 0, sticky = tk.NSEW)
hscrollbar.config(command = self.canvas.xview)
vscrollbar.config(command = self.canvas.yview)
# self
tk.Frame.__init__(self, self.canvas, *args, **kwargs)
self._selfItemID = self.canvas.create_window(0, 0, window = self, anchor = tk.NW)
# bindings
self.canvas.bind('<Configure>', self._onCanvasConfigure)
# ---------- setter ----------
def setSize(self, width, height):
print("setSize(%sx%s)" % (width, height))
self.canvas.configure( width = width, height = height )
# ---------- listen to GUI ----------
def _onCanvasConfigure(self, event):
self._updateSize(event.width, event.height)
# ---------- listen to model ----------
def updateScrollregion(self):
self.update_idletasks()
self._updateSize(self.canvas.winfo_width(), self.canvas.winfo_height())
self._updateScrollregion()
# ---------- internal ----------
def _updateSize(self, canvWidth, canvHeight):
hasChanged = False
requWidth = self.winfo_reqwidth()
newWidth = max(canvWidth, requWidth)
if newWidth != self.winfo_width():
hasChanged = True
requHeight = self.winfo_reqheight()
newHeight = max(canvHeight, requHeight)
if newHeight != self.winfo_height():
hasChanged = True
if hasChanged:
print("update size ({width}, {height})".format(width = newWidth, height = newHeight))
self.canvas.itemconfig(self._selfItemID, width = newWidth, height = newHeight)
return True
return False
def _updateScrollregion(self):
bbox = (0,0, self.winfo_reqwidth(), self.winfo_reqheight())
print("updateScrollregion%s" % (bbox,))
self.canvas.config( scrollregion = bbox )
# ==================== TEST ====================
if __name__ == '__main__':
labels = list()
def createLabel():
print("========= create label =========")
l = tk.Label(frame, text="test %s" % len(labels))
l.pack(anchor=tk.W)
labels.append(l)
frame.updateScrollregion()
def removeLabel():
print("========= remove label =========")
labels[-1].destroy()
del labels[-1]
frame.updateScrollregion()
root = tk.Tk()
tk.Button(root, text="+", command=createLabel).pack()
tk.Button(root, text="-", command=removeLabel).pack()
frame = ScrollableFrame(root, bg="white")
frame._parentFrame.pack(expand=tk.YES, fill=tk.BOTH)
createLabel()
frame.setSize(labels[0].winfo_width(), labels[0].winfo_height()*5.9)
#TODO: why is size saved in event object different from what I have specified here?
root.mainloop()
frame.setSize尝试使用库customTkinter，它包含一个可滚动框架小部件，它会自动在x或y方向添加滚动条。请注意，它不能与 tk.raise 一起使用，因为它本身不是 tk 框架，因此如果使用框架切换，您必须将其放入另一个框架中。 这是文档的链接