为什么滚动条在 canvas (tkinter) 中不起作用？

Question

我想要 window 框架来扩展整个 canvas 并有一个滚动条。 现在滚动条在视觉上就在那里，但不能用作滚动条。

root = Tk()

def onCanvasConfigure(e):
    my_canvas.configure(scrollregion = my_canvas.bbox("all")) #make the scrollfunction work
    my_canvas.itemconfig('window', height=(my_canvas.winfo_height()-100), width=(my_canvas.winfo_width()-100)) #set the frame window to canvas size


#Below code to add scrollbar to app. 
# Layers (root -> main_frame -> my_canvas -> window (frame))

# Create A Main Frame
main_frame = Frame(root)
main_frame.pack(fill=BOTH, expand=1)

# Create A Canvas
my_canvas = Canvas(main_frame)
my_canvas.pack(side=LEFT, fill=BOTH, expand=1)

# Add A Scrollbar To The Canvas
my_scrollbar = ttk.Scrollbar(main_frame, orient=VERTICAL, command=my_canvas.yview)
my_scrollbar.pack(side=RIGHT, fill=Y)

# Configure The Canvas
my_canvas.configure(yscrollcommand=my_scrollbar.set)


# Create ANOTHER Frame INSIDE the Canvas
window = Frame(my_canvas)

# Add that New frame To a Window In The Canvas
my_canvas.create_window((0,0), window=window, anchor="nw", tags="window")

my_canvas.bind("<Configure>", onCanvasConfigure)

见剪辑： https://jumpshare.com/v/TJlbWJac5d4rwp3DwnFw

Answer 1

由于您将内部框架window的大小调整为与 canvas 相同的大小，因此滚动区域将与scrollregion的大小大致相同，这使得滚动条未激活。

如果您设置的框架高度大于 canvas 的高度，将激活滚动条：

def onCanvasConfigure(e):
    # resize the frame with double height of canvas
    my_canvas.itemconfig('window', height=e.height*2, width=e.width)
    # update scrollregion
    my_canvas.configure(scrollregion=my_canvas.bbox("all"))