Tkinter:如何使Tkinter刷新和删除最后几行? [英] Tkinter: How to make Tkinter to refresh and delete last lines?
问题描述
问题是:因为我使用了w.delete，所以Tkinter的时针闪烁了，但是如果我不使用它，那么时针会重复..请帮助.
import Tkinter as tk; import time
from math import cos,sin,pi
import sys
root=tk.Tk(); root.title("Clock")
w = tk.Canvas(root, width=320, height=320, bg="#456", relief= "sunken", border=10)
w.pack()
size=300
def funA():
s=time.localtime()[5]
m=time.localtime()[4]
h=time.localtime()[3]
w.update()
degrees = 6*s
angle = degrees*pi*2/360
ox = 165
oy = 165
x = ox + size*sin(angle)*0.45
y = oy - size*cos(angle)*0.45
t = w.create_line(ox,oy,x,y, fill = "#ffc")
degrees1 = 6*m
angle1 = degrees1*pi*2/360
ox1 = 165
oy1 = 165
x1 = ox1 + size*sin(angle1)*0.4
y1 = oy1 - size*cos(angle1)*0.4
t1 = w.create_line(ox1,oy1,x1,y1, fill = "Red", width=6)
degrees2 = 30*h
angle2 = degrees2*pi*2/360
ox2 = 165
oy2 = 165
x2 = ox2 + size*sin(angle2)*0.2
y2 = oy2 - size*cos(angle2)*0.2
t2 = w.create_line(ox2,oy2,x2,y2, fill = "Black", width=8)
w.update()
root.after(200,funA)
w.delete(t1)
root.after(1500, funA)
uzr1 = tk.Label(root, text="12", bg="#456" )
uzr1.place(x=160, y=13)
uzr2 = tk.Label(root, text="6", bg="#456" )
uzr2.place(x=160, y=303)
uzr3 = tk.Label(root, text="3", bg="#456" )
uzr3.place(x=310, y=160)
uzr4 = tk.Label(root, text="9", bg="#456" )
uzr4.place(x=11, y=160)
def Quit():
root.after(700,root.destroy())
e = tk.Button(root,text="Quit", command=Quit)
e.pack()
root.mainloop()
如果我用funA，w.delete(t)书写，则时钟"二手时钟正在闪烁，如果不是，则表示其正在复制.
- t是二手
- t1是分钟针
- t2是时针
希望收到快速有用的回复
这里有些事情需要修复.对于一个，您不需要调用update.通常来说，您永远不要调用它，尽管一旦您理解了该规则存在的原因，该规则就可以被打破.调用update_idletasks是安全的，如果您需要调用update，通常这就是您想要的.即使采用适当的设计也可以避免.
第二，无需删除行并创建新行. canvas小部件具有名为coords的方法，可用于调整项目的坐标.
第三，您可以利用画布的标记功能.给每个钟针一个带有适当名称的标签(例如:秒"，分钟"，小时")，然后使用它来告诉画布要更新哪个项目.
最后，养成创建应用程序类或将应用程序代码放入函数中的习惯.它可以更轻松地解决在定义函数之前无法调用函数的问题，从而使您不必使用全局变量.
这是一个有效的示例:
import Tkinter as tk; import time
from math import cos,sin,pi
import sys
class MyApp(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
self.size=300
self.title("Clock")
self.w = tk.Canvas(self, width=320, height=320, bg="#456", relief= "sunken", border=10)
self.w.pack()
self.w.create_line(0,0,0,0, fill="#ffc", tags="hour")
self.w.create_line(0,0,0,0, fill="red", tags="minute")
self.w.create_line(0,0,0,0, fill="black", tags="second")
uzr1 = tk.Label(self, text="12", bg="#456" )
uzr1.place(x=160, y=13)
uzr2 = tk.Label(self, text="6", bg="#456" )
uzr2.place(x=160, y=303)
uzr3 = tk.Label(self, text="3", bg="#456" )
uzr3.place(x=310, y=160)
uzr4 = tk.Label(self, text="9", bg="#456" )
uzr4.place(x=11, y=160)
e = tk.Button(self,text="Quit", command=self.Quit)
e.pack()
self.update_clock()
def update_clock(self):
s=time.localtime()[5]
m=time.localtime()[4]
h=time.localtime()[3]
degrees = 6*s
angle = degrees*pi*2/360
ox = 165
oy = 165
x = ox + self.size*sin(angle)*0.45
y = oy - self.size*cos(angle)*0.45
self.w.coords("hour", (ox,oy,x,y))
degrees1 = 6*m
angle1 = degrees1*pi*2/360
ox1 = 165
oy1 = 165
x1 = ox1 + self.size*sin(angle1)*0.4
y1 = oy1 - self.size*cos(angle1)*0.4
self.w.coords("minute", (ox1,oy1,x1,y1))
degrees2 = 30*h
angle2 = degrees2*pi*2/360
ox2 = 165
oy2 = 165
x2 = ox2 + self.size*sin(angle2)*0.2
y2 = oy2 - self.size*cos(angle2)*0.2
self.w.coords("second",(ox2,oy2,x2,y2))
self.after(1000, self.update_clock)
def Quit(self):
self.after(700,self.destroy())
app = MyApp()
app.mainloop()
Problem is: Clock hands in Tkinter flashes because I use w.delete, but if i don't use it then clock hands duplicate.. Please help.
import Tkinter as tk; import time
from math import cos,sin,pi
import sys
root=tk.Tk(); root.title("Clock")
w = tk.Canvas(root, width=320, height=320, bg="#456", relief= "sunken", border=10)
w.pack()
size=300
def funA():
s=time.localtime()[5]
m=time.localtime()[4]
h=time.localtime()[3]
w.update()
degrees = 6*s
angle = degrees*pi*2/360
ox = 165
oy = 165
x = ox + size*sin(angle)*0.45
y = oy - size*cos(angle)*0.45
t = w.create_line(ox,oy,x,y, fill = "#ffc")
degrees1 = 6*m
angle1 = degrees1*pi*2/360
ox1 = 165
oy1 = 165
x1 = ox1 + size*sin(angle1)*0.4
y1 = oy1 - size*cos(angle1)*0.4
t1 = w.create_line(ox1,oy1,x1,y1, fill = "Red", width=6)
degrees2 = 30*h
angle2 = degrees2*pi*2/360
ox2 = 165
oy2 = 165
x2 = ox2 + size*sin(angle2)*0.2
y2 = oy2 - size*cos(angle2)*0.2
t2 = w.create_line(ox2,oy2,x2,y2, fill = "Black", width=8)
w.update()
root.after(200,funA)
w.delete(t1)
root.after(1500, funA)
uzr1 = tk.Label(root, text="12", bg="#456" )
uzr1.place(x=160, y=13)
uzr2 = tk.Label(root, text="6", bg="#456" )
uzr2.place(x=160, y=303)
uzr3 = tk.Label(root, text="3", bg="#456" )
uzr3.place(x=310, y=160)
uzr4 = tk.Label(root, text="9", bg="#456" )
uzr4.place(x=11, y=160)
def Quit():
root.after(700,root.destroy())
e = tk.Button(root,text="Quit", command=Quit)
e.pack()
root.mainloop()
If i write in funA, w.delete(t), then Clock second-hand is flashing, if not then its duplicating.. So it is with all clock hands..
- t is Second hand
- t1 is Minute hand
- t2 is Hour hand
Hoping to receive fast useful reply
There are a few things here that need fixing. For one, you don't need to call update. Generally speaking you should never call it, though that rule can be broken once you understand why that rule exists. It's safe to call update_idletasks which is generally what you want if you feel the need to call update. Even that can be avoided with proper design.
Second, there is no need to delete the line and create a new line. The canvas widget has a method named coords which can be used to adjust the coordinates of an item.
Third, you can leverage the tagging feature of the canvas. Give each clock hand a tag with a suitable name (eg: "second", "minute", "hour") and you use that to tell the canvas which item to update.
Finally, get in the habit of either creating an application class, or putting your application code in a function. It makes it easier to solve the problem of not being able to call a function until it is defined, and makes it so that you don't have to use global variables.
Here is a working example:
import Tkinter as tk; import time
from math import cos,sin,pi
import sys
class MyApp(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
self.size=300
self.title("Clock")
self.w = tk.Canvas(self, width=320, height=320, bg="#456", relief= "sunken", border=10)
self.w.pack()
self.w.create_line(0,0,0,0, fill="#ffc", tags="hour")
self.w.create_line(0,0,0,0, fill="red", tags="minute")
self.w.create_line(0,0,0,0, fill="black", tags="second")
uzr1 = tk.Label(self, text="12", bg="#456" )
uzr1.place(x=160, y=13)
uzr2 = tk.Label(self, text="6", bg="#456" )
uzr2.place(x=160, y=303)
uzr3 = tk.Label(self, text="3", bg="#456" )
uzr3.place(x=310, y=160)
uzr4 = tk.Label(self, text="9", bg="#456" )
uzr4.place(x=11, y=160)
e = tk.Button(self,text="Quit", command=self.Quit)
e.pack()
self.update_clock()
def update_clock(self):
s=time.localtime()[5]
m=time.localtime()[4]
h=time.localtime()[3]
degrees = 6*s
angle = degrees*pi*2/360
ox = 165
oy = 165
x = ox + self.size*sin(angle)*0.45
y = oy - self.size*cos(angle)*0.45
self.w.coords("hour", (ox,oy,x,y))
degrees1 = 6*m
angle1 = degrees1*pi*2/360
ox1 = 165
oy1 = 165
x1 = ox1 + self.size*sin(angle1)*0.4
y1 = oy1 - self.size*cos(angle1)*0.4
self.w.coords("minute", (ox1,oy1,x1,y1))
degrees2 = 30*h
angle2 = degrees2*pi*2/360
ox2 = 165
oy2 = 165
x2 = ox2 + self.size*sin(angle2)*0.2
y2 = oy2 - self.size*cos(angle2)*0.2
self.w.coords("second",(ox2,oy2,x2,y2))
self.after(1000, self.update_clock)
def Quit(self):
self.after(700,self.destroy())
app = MyApp()
app.mainloop()
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