Oh man, I feel your pain—this Treeview horizontal scroll problem in Python 2.7.14 with the bundled Tk 8.5.15 is such a frustrating gotcha. When you're in browse mode, trying to get the scrollbar to play nice either results in your parent container getting stretched way too wide (thanks to summing up column widths) or the scrollbar just sitting there doing nothing. Let's break down a solid fix for this:

Core Issue Recap #

By default, the Treeview's total width is the sum of all its column widths. Add too many columns, and it'll just blow out the parent container instead of triggering the horizontal scrollbar. We need to force the Treeview to respect the parent container's width while letting its internal content scroll horizontally.

Step-by-Step Solution #

Here's a practical implementation that addresses the problem:

1. Wrap Treeview and Scrollbar in a Frame
   Using a Frame as the parent container lets us control the visible area for the Treeview, ensuring it doesn't escape beyond the space we allocate.

2. Link Scrollbar and Treeview Properly
   Make sure the Treeview's xscrollcommand is tied to the scrollbar's set method, and the scrollbar's command links back to the Treeview's xview method. This connects their behaviors.

3. Dynamic Width Binding
   Bind the container Frame's <Configure> event to adjust the Treeview's width dynamically. This ensures whenever the container resizes, the Treeview stays within bounds, and content beyond that triggers the scrollbar.

Working Code Example #

import Tkinter as tk
import ttk

root = tk.Tk()
root.title("Treeview Horizontal Scroll Fix")

# Create a wrapping frame to contain the Treeview and scrollbar
tree_container = tk.Frame(root)
tree_container.pack(fill=tk.BOTH, expand=True, padx=8, pady=8)

# Horizontal scrollbar setup
horizontal_scroll = ttk.Scrollbar(tree_container, orient=tk.HORIZONTAL)
horizontal_scroll.pack(side=tk.BOTTOM, fill=tk.X)

# Treeview configuration (browse mode)
tree = ttk.Treeview(tree_container, xscrollcommand=horizontal_scroll.set)
tree.pack(side=tk.TOP, fill=tk.BOTH, expand=True)
horizontal_scroll.config(command=tree.xview)

# Set up columns (simulating a wide set of columns)
column_names = ["Column {}".format(i) for i in range(1, 12)]
tree["columns"] = column_names
tree["show"] = "headings"  # Enable browse mode by hiding the default tree column

# Initialize column widths
for col in column_names:
    tree.heading(col, text=col)
    tree.column(col, width=120)  # Set initial column width

# Bind container resize event to adjust Treeview width
def adjust_tree_width(event):
    # Get the container's current width, use it to set Treeview's visible width
    container_width = tree_container.winfo_width()
    tree.configure(width=container_width)

tree_container.bind("<Configure>", adjust_tree_width)

# Add sample data to test scrolling
for row_idx in range(6):
    row_values = ["Row {} - {}".format(row_idx, col) for col in column_names]
    tree.insert("", tk.END, values=row_values)

root.mainloop()

Key Notes #

• Browse Mode: Setting show="headings" removes the default hierarchical column, which is essential for table-style browsing.
• Dynamic Resizing: The <Configure> event handler ensures the Treeview always fits within its container, so any column width adjustments that push total content width beyond the container will activate the scrollbar.
• Tk 8.5 Quirks: In this version, double-check that the scrollbar and Treeview are properly linked—sometimes the xview method can be finicky if the bindings aren't set correctly.

内容的提问来源于stack exchange，提问作者Kumba