我是 Python 新手，在向 Canvas 添加鼠标滚动操作时遇到问题。我有一个垂直滚动条。当我手动滚动滚动条或将鼠标悬停在滚动条上并滚动鼠标滚轮时，滚动条工作正常。我的问题是，我希望能够在 Canvas 上滚动鼠标滚轮，甚至只是在框架上滚动，只要鼠标悬停在其上，其中的内容就会滚动。
我花了几个小时在 stackoverflow 上查看与此相关的所有类似问题，但我的修改似乎都不起作用。我目前遇到一个无法纠正的奇怪错误。由于我的修改，错误仅在我开始滚动时显示，但不会导致崩溃。错误是:
Exception in Tkinter callback
Traceback (most recent call last):
File "C:\Users\twaku\Anaconda3\lib\tkinter\__init__.py", line 1699, in __call__
return self.func(*args)
File "C:/Users/twaku/PycharmProjects/DCSui/FileToSubmit.py", line 152, in _on_mousewheel
self.canvas.yview_scroll(int(-1 * (event.delta / 120), "units"))
TypeError: 'str' object cannot be interpreted as an integer
现在，如果我删除 int 类型转换，则会收到此错误:
Exception in Tkinter callback
Traceback (most recent call last):
File "C:\Users\twaku\Anaconda3\lib\tkinter\__init__.py", line 1699, in __call__
return self.func(*args)
File "C:/Users/twaku/PycharmProjects/DCSui/FileToSubmit.py", line 156, in _on_mousewheel
self.canvas.yview_scroll(-1 * (event.delta / 120), "units")
File "C:\Users\twaku\Anaconda3\lib\tkinter\__init__.py", line 1745, in yview_scroll
self.tk.call(self._w, 'yview', 'scroll', number, what)
_tkinter.TclError: expected integer but got "1.0"
所以现在我在这两个错误之间来回徘徊。
这是我的代码:
from tkinter import *
import tkinter as tk
import time
import xlrd
root = Tk()
root.state('zoomed') # full screen -windowed
# ------------------INTRODUCTION BLOCK--------------
f1 = Frame(root, width=900, height=700, relief=SUNKEN)
f1.grid_rowconfigure(1, weight=1)
f1.grid_columnconfigure(2, weight=1)
f1.pack(fill=BOTH, expand=1, side=BOTTOM)
root.title("Diagram Scroll Test")
Tops = Frame(root, width=1600, height=50, relief=SUNKEN)
Tops.pack(side=TOP)
# ------------------TIME--------------
localtime = time.asctime(time.localtime(time.time()))
# -----------------INFO TOP------------
lblinfo = Label(Tops, font=('aria', 30, 'bold'), text="My Diagram Scroll Test",
fg="steel blue", bd=10, anchor='w')
lblinfo.grid(row=0, column=0)
lblinfo = Label(Tops, font=('aria', 20,), text=localtime, fg="steel blue", anchor=W)
lblinfo.grid(row=1, column=0)
lblinfo = Label(Tops, font=('aria', 15, 'bold'), text="Please help", fg="steel blue", bd=10,
anchor='w')
lblinfo.grid(row=2, column=0)
# ------------------CANVAS DEFINITION-------------
class CanvasDemo(Frame):
def __init__(self,root):
Frame.__init__(self,root)
self.canvas = tk.Canvas(root, borderwidth=0)
self.canvas.bind_all("<MouseWheel>", self._on_mousewheel)
self.frame = tk.Frame(self.canvas)
self.vsb = tk.Scrollbar(root, orient="vertical", command=self.canvas.yview)
self.canvas.configure(yscrollcommand=self.vsb.set)
root.state('zoomed')
self.vsb.pack(side="right", fill="y")
self.canvas.config(width=root.winfo_screenwidth(), height=root.winfo_screenheight())
# self.canvas.pack(side="left", fill="both", expand="1")
self.canvas.pack(fill="both", expand="1")
self.canvas.create_window((4, 4), window=self.frame, anchor="nw",
tags="self.frame")
self.frame.bind("<Configure>", self.onFrameConfigure)
self.populate()
# ------------------CODE TO CREATE BLOCK DIAGRAMS-------------
def populate(self):
i = 0
turnCount = 0 # Keeps track of how many boxes is used to trigger a turn
# Create Small starter box
lineVarx1 = 70
lineVary1 = 50
lineVarx2 = 120
lineVary2 = 50
varx1 = 120
vary1 = 25
varx2 = 220
vary2 = 75
varblk = 1
varline = 1
self.canvas.create_rectangle(20, 40, 70, 60, fill="green", tags="start")
while i < 200: # Provides 104 blocks
# ------------------IF STATEMENT TO CONTROL WHEN DIAGRAM TURNS-------------
if turnCount == 12: # At Turn Point, initiating turn sequence
lineVarx2 = lineVarx2 - 25
self.canvas.create_line(lineVarx1, lineVary1, lineVarx2, lineVary2, arrow="last", tags="to_r1")
# Downward line
lineVarx1 = lineVarx2
lineVary1 = lineVary2
lineVary2 = lineVary2 + 50
self.canvas.create_line(lineVarx1, lineVary1, lineVarx2, lineVary2, arrow="last", tags="to_r1")
# long line to left
lineVarx1 = lineVarx2
lineVary1 = lineVary2
lineVarx2 = lineVarx2 - 1825
self.canvas.create_line(lineVarx1, lineVary1, lineVarx2, lineVary2, arrow="last", tags="to_r1")
# Downward line
lineVarx1 = lineVarx2
lineVary1 = lineVary2
lineVary2 = lineVary2 + 50
self.canvas.create_line(lineVarx1, lineVary1, lineVarx2, lineVary2, arrow="last", tags="to_r1")
lineVary1 = lineVary2
lineVarx2 = lineVarx2 + 50
varx1 = lineVarx2
vary1 = lineVary2 - 25
varx2 = lineVarx2 + 100
vary2 = lineVary2 + 25
turnCount = 0
self.canvas.create_line(lineVarx1, lineVary1, lineVarx2, lineVary2, arrow="last", tags="to_r1")
self.canvas.create_rectangle(varx1, vary1, varx2, vary2, fill="bisque", tags="r1")
self.canvas.create_text(varx1 + 20, vary1, fill="darkblue", anchor=NW,
text="Hi")
self.canvas.create_text(varx1 + 20, vary1 + 10, fill="darkblue", anchor=NW,
text="bye")
self.canvas.create_text(varx1 + 20, vary1 + 20, fill="darkblue", anchor=NW,
text="fly")
lineVarx1 = lineVarx1 + 150
lineVarx2 = lineVarx2 + 150
varx1 = varx1 + 150
varx2 = varx2 + 150
i += 1
turnCount += 1
# "End" Block
lineVarx1 = varx2 - 150
lineVarx2 = lineVarx1 + 50
varx1 = lineVarx2
vary1 = lineVary1 - 10
varx2 = varx1 + 50
vary2 = lineVary1 + 10
self.canvas.create_line(lineVarx1, lineVary1, lineVarx2, lineVary2, arrow="last", tags="to_r1")
self.canvas.create_rectangle(varx1, vary1, varx2, vary2, fill="red", tags="r1")
def _on_mousewheel(self, event):
self.canvas.yview_scroll(-1 * (event.delta / 120), "units")
def onFrameConfigure(self, event):
'''Reset the scroll region to encompass the inner frame'''
self.canvas.configure(scrollregion=self.canvas.bbox("all"))
def qexit():
root.destroy()
btnexit = Button(f1, padx=16, pady=7, bd=10, fg="black", font=('ariel', 12, 'bold'), width=8, text="EXIT",
bg="powder blue", command=qexit)
btnexit.grid(row=15, column=2)
canvas = CanvasDemo(root)
canvas.pack()
mainloop()
最佳答案
除法的结果是 float 。尝试使用整数除法:
def _on_mousewheel(self, event):
self.canvas.yview_scroll(-1 * (event.delta // 120), "units")
here:--^
现在，您可能想要检查鼠标指针悬停在哪个小部件上方，因为当鼠标指针悬停在滚动条上时会调用 _on_mousewheel() 函数，使其滚动速度提高两倍。
关于python - 用于在 Canvas 上滚动的 Tkinter 鼠标滚轮操作，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/51568717/