Python tk 滚动条在文本超出屏幕后失效

Question

每当我在这个框里填入文字时，水平滚动条都能正常工作，直到文字在屏幕上显示出来。

但是，如果行数超过了屏幕能显示的数量，当我把文字向下滚动时，水平滚动条就变得无效，直到文字又变得太长，无法再放在一行里。

这是我非常基础的代码：

from Tkinter import *
import Tkinter,tkFileDialog, tkFont

w = Label(root, text="Hello, world!")
w.pack()


textfr=Frame(root)
t=Text(textfr, width=100, height=10,font=("Arial",12),wrap=NONE)
t.insert('1.0', 'here is my text to insert')

Yscroll=Scrollbar(textfr, orient=VERTICAL)
Xscroll=Scrollbar(textfr, orient=HORIZONTAL)

t.configure(yscrollcommand=Yscroll.set)
t.configure(xscrollcommand=Xscroll.set)

Yscroll.config(command=t.yview)
Xscroll.config(command=t.xview)


        #pack everything

Yscroll.pack(side=RIGHT,fill=Y)
Xscroll.pack(side=BOTTOM,fill=X)
t.pack(side=LEFT, fill=BOTH, expand=TRUE)
textfr.pack(side=TOP, fill=BOTH, expand=TRUE)


root.mainloop()

可惜我找不到合适的解决办法，尽管这个问题其实很简单。

有没有什么想法？

Answer 1

from Tkinter import *

class AutoScrollbar(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:
            # grid_remove is currently missing from Tkinter!
            self.tk.call("grid", "remove", self)
        else:
            self.grid()
        Scrollbar.set(self, lo, hi)
    def pack(self, **kw):
        raise TclError, "cannot use pack with this widget"
    def place(self, **kw):
        raise TclError, "cannot use place with this widget"


root = Tk()

vscrollbar = AutoScrollbar(root)
vscrollbar.grid(row=0, column=1, sticky=N+S)
hscrollbar = AutoScrollbar(root, orient=HORIZONTAL)
hscrollbar.grid(row=1, column=0, sticky=E+W)

canvas = Canvas(root,
                yscrollcommand=vscrollbar.set,
                xscrollcommand=hscrollbar.set)
canvas.grid(row=0, column=0, sticky=N+S+E+W)

vscrollbar.config(command=canvas.yview)
hscrollbar.config(command=canvas.xview)

# make the canvas expandable
root.grid_rowconfigure(0, weight=1)
root.grid_columnconfigure(0, weight=1)

#
# create canvas contents

frame = Frame(canvas)
frame.rowconfigure(1, weight=1)
frame.columnconfigure(1, weight=1)

rows = 20
for i in range(1,rows):
    for j in range(1,50):
        button = Button(frame, padx=7, pady=7, text="[%d,%d]" % (i,j))
        button.grid(row=i, column=j, sticky='news')

canvas.create_window(0, 0, anchor=NW, window=frame)

frame.update_idletasks()

canvas.config(scrollregion=canvas.bbox("all"))

root.mainloop()

这只是一个使用按钮的简单示例。你可以改变for循环中range()语句里的数字，看看效果。这样你就能理解这个代码了，然后可以根据自己的需要进行调整。希望这对你有帮助。