在 Tkinter 中用鼠标实时绘图

Question

我对在 Tkinter 中绘图相当得心应手，但您只有在松开鼠标按钮后才能看到形状。拖动鼠标时如何看到形状？我已经完成了下面代码的一半，但是如果你运行它你会看到它不会更新以删除由运动功能制作的每张图。

from tkinter import *

window = Tk()

canvas = Canvas(bg='black')
canvas.pack()

def locate_xy(event):
    global current_x, current_y
    current_x, current_y = event.x, event.y

def draw_circle(event):
    global current_x, current_y
    canvas.create_oval((current_x, current_y, event.x, event.y), outline='white')
    current_x, current_y = event.x, event.y

def update_circle(event):
    global current_x, current_y
    canvas.create_oval((current_x, current_y, event.x, event.y), outline='white')

canvas.bind('<ButtonPress-1>', locate_xy)
canvas.bind('<ButtonRelease-1>', draw_circle)
canvas.bind('<B1-Motion>', update_circle)

window.mainloop()

Answer 1

您已经在通过事件 <B1-Motion> 按下左键来跟踪鼠标移动，因此只需在此处添加绘图：

from tkinter import *

window = Tk()

canvas = Canvas(bg='black')
canvas.pack()

def draw_line(event):
    x, y = event.x, event.y
    canvas.create_oval((x-2, y-2, x+2, y+2), outline='white')

canvas.bind('<B1-Motion>', draw_line)

window.mainloop()

Answer 2

您只需在 locate_xy() 内创建椭圆并更新其在 update_circle() 内的坐标。 <ButtonRelease-1> 的绑定不是必需的：

def locate_xy(event):
    global current_x, current_y, current_item
    current_x, current_y = event.x, event.y
    # create the oval item and save its ID
    current_item = canvas.create_oval((current_x, current_y, event.x, event.y), outline='white')

def update_circle(event):
    # update coords of the oval item
    canvas.coords(current_item, (current_x, current_y, event.x, event.y))

canvas.bind('<ButtonPress-1>', locate_xy)
canvas.bind('<B1-Motion>', update_circle)

在 Tkinter 中用鼠标实时绘图

Real time drawing with mouse in Tkinter

python

tkinter

canvas