python - Tkinter : Moving more than one object at once

Question

我对 tkinter 还很陌生，我正在尝试创建一个网络模拟器。我制作了一个更简单的程序版本，没有所有额外的网络内容。我已经被一个问题困扰了很长一段时间了。我不知道如何做到这一点，所以当我尝试 move 其中一个圆圈时，它会随之 move 文本。我有一个想法，当我单击向下时删除文本，这样我就可以 move 对象并在放下对象时重新创建文本，但我不确定如何执行此操作。当然欢迎任何其他想法。

这是我的图书馆:

from Tkinter import *
import time

#Window class for making different windows

class Window:

#Constructor
def __init__(self, window, colour="black", width=600, height=400):
    #Set variables
    self.width = width
    self.height = height
    self.colour = colour

    #This dictionary is used to keep track of an item being dragged
    self._drag_data = {"x": 0, "y": 0, "item": None}

    #Create canvas
    self.canvas = Canvas(window, bg=self.colour, height=self.height, width=self.width)
    self.canvas.pack()

    #Add bindings for clicking, dragging and releasing over any object with the "circledrag" tag
    self.canvas.tag_bind("circledrag", "<ButtonPress-1>", self.OnCircleButtonPress)
    self.canvas.tag_bind("circledrag", "<ButtonRelease-1>", self.OnCircleButtonRelease)
    self.canvas.tag_bind("circledrag", "<B1-Motion>", self.OnCircleMotion)

#This is used to draw particle objects on the canvas, notice the tag that has been added as an attribute
def _create_circle(self, xcoord, ycoord, color):
    self.canvas.create_oval(xcoord-25, ycoord-25, xcoord+25, ycoord+25, outline=color, fill=color, tags = "circledrag")

#This is used to draw text on top of the object on the canvas
def _create_text(self, xcoord, ycoord, text):
    self.canvas.create_text(xcoord, ycoord, text = text, tags = ("circledrag", "text"))

#This uses the find_closest method to get store the x and y positions of the nearest item into the dictionary
def OnCircleButtonPress(self, event):
    #print self.canvas.find_withtag("Current")
    self.canvas.delete("text")

    '''Begin drag of an object'''
    # record the item and its location
    self._drag_data["item"] = self.canvas.find_closest(event.x, event.y)[0]
    self._drag_data["x"] = event.x
    self._drag_data["y"] = event.y

#This clears the dictionary once the mouse button has been released
def OnCircleButtonRelease(self, event):
    '''End drag of an object'''
    # reset the drag information
    self._drag_data["item"] = None
    self._drag_data["x"] = 0
    self._drag_data["y"] = 0

#This moves the item as it is being dragged around the screen
def OnCircleMotion(self, event):
    '''Handle dragging of an object'''
    # compute how much this object has moved
    delta_x = event.x - self._drag_data["x"]
    delta_y = event.y - self._drag_data["y"]
    # move the object the appropriate amount
    self.canvas.move(self._drag_data["item"], delta_x, delta_y)
    # record the new position
    self._drag_data["x"] = event.x
    self._drag_data["y"] = event.y

class DragCircle:
#Constructor
def __init__(self, window, width=100, height=100, colour="red", text = "test"):
    self.window = window
    self.circle = self.window._create_circle(width, height, colour)
    self.circle_text = self.window._create_text(width, height, text)

这是主程序:

from Tkinter import *
import my_module2

#Make a window from my own class
window = Tk()
window.title("Drag & Drop")

#Create an instance of the window class
main_window = my_module2.Window(window)

#Create a circle object from the DragCircle class
circle = my_module2.DragCircle(main_window)
circle2 = my_module2.DragCircle(main_window, 200, 200, "green", "hello")

#Start the animation loop
window.mainloop()

我想知道如何同时 move 两个物体。

Answer 1

每次创建圆圈/文本对时，创建一个唯一的标记并将该标记与圆圈和文本相关联。然后，您可以使用这个独特的标签同时 move 两个对象。

例如，将您的 DragCircle 构造函数修改为如下所示:

class DragCircle:
    #Constructor
    def __init__(self, window, width=100, height=100, colour="red", text = "test"):
        self.window = window
        tag = "circle-%d" % id(self)
        self.circle = self.window._create_circle(width, height, colour, tag)
        self.circle_text = self.window._create_text(width, height, text, tag)

接下来，修改 _create_circle 和 _create_text 函数以接受该标记:

def _create_circle(self, xcoord, ycoord, color, tag):
    id_=self.canvas.create_oval(xcoord-25, ycoord-25, xcoord+25, ycoord+25, outline=color, fill=color, tags = ("circledrag", tag))

#This is used to draw text on top of the object on the canvas
def _create_text(self, xcoord, ycoord, text, tag):
    self.canvas.create_text(xcoord, ycoord, text = text, tags = ("circledrag", "text", tag))

最后，修改您的 OnCircleButtonPress 以获取标签并使用它来 move 对象:

def OnCircleButtonPress(self, event):
    ...
    item = self.canvas.find_closest(event.x, event.y)[0]
    tags = self.canvas.gettags(item)
    for tag in tags:
        if tag.startswith("circle-"):
            break
    self._drag_data["item"] = tag
    ...