[英]python tkinter canvas not resizing
我正在尝试对一些 tkinter 控件进行子类化以制作一个自动滚动框架以供在我的程序中使用,我只希望它垂直滚动,并且当添加需要它水平滚动而不是调整父级大小以适合的小部件时。 这个框架中的 go 的 widgets 并不是都是在运行时定义的,是动态创建的,所以它必须对事件做出反应。 我有一些部分工作的代码,因为我运行它,我可以使用底部的按钮动态添加和删除标签,如果我这样做而不先手动调整 window 的大小,那么它会按预期工作。 但是,如果我手动调整 window 的大小,水平调整将停止工作:
from tkinter import *
__all__ = ["VerticalScrolledFrame"]
class VerticalScrolledFrame(Frame):
def __init__(self, parent, *args, **kw):
Frame.__init__(self, parent, *args, **kw)
self.grid_columnconfigure(1, weight=1)
self.grid_rowconfigure(1, weight=1)
# create a canvas object and a vertical scrollbar for scrolling it
self.vscrollbar = Scrollbar(self, orient=VERTICAL)
self.vscrollbar.grid(column=2, row=1, sticky="nesw")
self.canvas = Canvas(self, bd=0, highlightthickness=0, yscrollcommand=self.vscrollbar.set, height=10, width=10)
self.canvas.grid(column=1, row=1, sticky="nesw")
self.vscrollbar.config(command=self.canvas.yview)
# reset the view
self.canvas.xview_moveto(0)
self.canvas.yview_moveto(0)
# create a frame inside the canvas which will be scrolled with it
self.interior = Frame(self.canvas)
self.interior_id = self.canvas.create_window(0, 0, window=self.interior, anchor=NW)
self.interior.bind('<Configure>', self._configure_interior)
# track changes to the canvas and frame width and sync them,
# also updating the scrollbar
def _configure_interior(self, event=None):
print("config interior")
# update the scrollbars to match the size of the inner frame
size = (self.interior.winfo_width(), self.interior.winfo_height())
self.canvas.config(scrollregion="0 0 %s %s" % size)
if self.interior.winfo_reqwidth() > self.canvas.winfo_width():
# update the canvas's width to fit the inner frame
self.canvas.config(width=self.interior.winfo_reqwidth())
if __name__ == "__main__":
labels = []
labels2 = []
def add1():
l = Label(f.interior, text=str(len(labels)+1))
l.grid(column=len(labels)+1, row=1)
labels.append(l)
def remove1():
l = labels.pop()
l.grid_forget()
l.destroy()
def add2():
l = Label(f.interior, text=str(len(labels2)+1))
l.grid(column=1, row=len(labels2)+1)
labels2.append(l)
def remove2():
l = labels2.pop()
l.grid_forget()
l.destroy()
app = Tk()
app.grid_columnconfigure(1, weight=1)
app.grid_columnconfigure(2, weight=1)
app.grid_rowconfigure(1, weight=1)
f = VerticalScrolledFrame(app)
f.grid(column=1, row=1, columnspan=2, sticky="nesw")
Button(app, text="Add-H", command=add1).grid(column=1, row=2, sticky="nesw")
Button(app, text="Remove-H", command=remove1).grid(column=2, row=2, sticky="nesw")
Button(app, text="Add-V", command=add2).grid(column=1, row=3, sticky="nesw")
Button(app, text="Remove-V", command=remove2).grid(column=2, row=3, sticky="nesw")
app.mainloop()
我只在 windows 上工作并使用 python 3.3,我也尝试了 3.4 但没有变化。
为什么调整 window 会停止调用:
self.canvas.config(width=self.interior.winfo_reqwidth())
从工作?
编辑:布赖恩奥克利的回应是有道理的,所以我可以理解这种行为,但是我现在已经更改了我的代码以在调整 window 大小时也处理对 canvas 大小的更改:
from tkinter import *
__all__ = ["VerticalScrolledFrame"]
class VerticalScrolledFrame(Frame):
def __init__(self, parent, *args, **kw):
Frame.__init__(self, parent, *args, **kw)
p = parent
while True:
if p.winfo_class() in ['Tk', 'Toplevel']:
break
else:
p = self._nametowidget(p.winfo_parent())
self.root_window = p
self.grid_columnconfigure(1, weight=1)
self.grid_rowconfigure(1, weight=1)
# create a canvas object and a vertical scrollbar for scrolling it
self.vscrollbar = Scrollbar(self, orient=VERTICAL)
self.vscrollbar.grid(column=2, row=1, sticky="nesw")
self.canvas = Canvas(self, bd=0, highlightthickness=0, yscrollcommand=self.vscrollbar.set, height=10, width=10)
self.canvas.grid(column=1, row=1, sticky="nesw")
self.vscrollbar.config(command=self.canvas.yview)
# reset the view
self.canvas.xview_moveto(0)
self.canvas.yview_moveto(0)
# create a frame inside the canvas which will be scrolled with it
self.interior = Frame(self.canvas)
self.interior_id = self.canvas.create_window(0, 0, window=self.interior, anchor=NW)
self.interior.bind('<Configure>', self._configure_interior)
self.canvas.bind('<Configure>', self._configure_canvas)
# track changes to the canvas and frame width and sync them,
# also updating the scrollbar
def _configure_interior(self, event=None):
print("config interior")
# update the scrollbars to match the size of the inner frame
size = (self.interior.winfo_width(), self.interior.winfo_height())
self.canvas.config(scrollregion="0 0 %s %s" % size)
if self.interior.winfo_reqwidth() >= self.canvas.winfo_width():
# update the canvas's width to fit the inner frame
# only works before mainloop
self.canvas.config(width=self.interior.winfo_reqwidth())
screen_h = self.winfo_screenheight()
if ((self.root_window.winfo_rooty() + self.root_window.winfo_height() - self.canvas.winfo_height() + self.interior.winfo_reqheight()) < screen_h):
self.canvas.configure(height=self.interior.winfo_reqheight())
def _configure_canvas(self, event=None):
print("config canvas")
if self.interior.winfo_reqwidth() < self.canvas.winfo_width():
self.canvas.itemconfigure(self.interior_id, width=self.canvas.winfo_width())
elif self.interior.winfo_reqwidth() > self.canvas.winfo_width():
self.canvas.config(width=self.interior.winfo_reqwidth())
if (self.interior.winfo_reqheight() < self.canvas.winfo_height()) or (self.interior.winfo_height() < self.canvas.winfo_height()):
self.canvas.itemconfigure(self.interior_id, height=self.canvas.winfo_height())
if __name__ == "__main__":
labels = []
labels2 = []
def add1():
## app.geometry("")
l = Label(f.interior, text=str(len(labels)+1))
l.grid(column=len(labels)+1, row=1)
f.interior.grid_columnconfigure(len(labels)+1, weight=1, minsize=l.winfo_reqwidth())
labels.append(l)
def remove1():
## app.geometry("")
l = labels.pop()
l.grid_forget()
f.interior.grid_columnconfigure(len(labels)+2, weight=0, minsize=0)
l.destroy()
def add2():
l = Label(f.interior, text=str(len(labels2)+1))
l.grid(column=1, row=len(labels2)+1)
f.interior.grid_rowconfigure(len(labels2)+1, weight=1, minsize=l.winfo_reqheight())
labels2.append(l)
def remove2():
l = labels2.pop()
l.grid_forget()
f.interior.grid_rowconfigure(len(labels2)+2, weight=0, minsize=0)
l.destroy()
app = Tk()
app.grid_columnconfigure(1, weight=1)
app.grid_columnconfigure(2, weight=1)
app.grid_rowconfigure(1, weight=1)
f = VerticalScrolledFrame(app)
f.grid(column=1, row=1, columnspan=2, sticky="nesw")
Button(app, text="Add-H", command=add1).grid(column=1, row=2, sticky="nesw")
Button(app, text="Remove-H", command=remove1).grid(column=2, row=2, sticky="nesw")
Button(app, text="Add-V", command=add2).grid(column=1, row=3, sticky="nesw")
Button(app, text="Remove-V", command=remove2).grid(column=2, row=3, sticky="nesw")
for i in range(0,10):
add1()
add2()
app.mainloop()
我现在看到的问题是,如果我在调整 window 大小之前垂直添加项目,则会为添加的每个小部件调用_configure_interior
function,并且 window 要么垂直调整大小以适应(如果在 window 大小调整之前),它应该更新scrollregion(和滚动条)如果没有,但是在调整 window 的大小后,随着每个小部件的添加, _configure_interior
停止被调用,如果我手动调用它,滚动条仍然没有更新?
调整窗口大小的原因为何会阻止对以下内容的调用:
self.canvas.config(宽度= self.interior.winfo_reqwidth())
那是因为您的代码已绑定到框架更改。 当用户调整窗口大小时,您调整窗口大小,而不是frame大小。 如果希望在调整窗口大小时调用该函数,则除了自动调整内部框架的大小外,还必须将其或类似的函数绑定到调整窗口或画布的大小。
您还需要注意,如果用户调整窗口大小,则在画布中向框架添加对象不会使窗口变大。 用户选择的窗口大小将覆盖正在调整大小的内部窗口小部件的计算大小。 您必须将几何图形重置为空字符串,以使其自动增长。
在所有 tkinter 个“可滚动”框架示例中,这是唯一一个实际使用动态添加的小部件的示例。 关键是更新 canvas 和子窗口的框架高度以响应子框架的请求高度。
框架"<Configure>"
处理程序中的以下代码段
self.canvas.config(height=self.interior.winfo_reqheight())
self.canvas.itemconfig(self.interior_id, height=self.interior.winfo_reqheight())
修复 canvas 大小,以便内部框架将填充它。
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