修改代码拖动字符串

Question

我一直在试图理解我从 Bryan Oakley here 那里得到的代码。目前，此代码允许用户使用 tkinter 拖动两个椭圆。我希望能够修改此代码，以便用户能够从两个列表中拖动字符串（键值对）并匹配它们，而不是椭圆。例如，我希望用户能够从一个列表中拖动像“User”这样的字符串，从另一个列表中拖动“Ryan”并匹配它们。对于我应该如何修改代码以便用户能够拖动这两个字符串的任何输入，我将不胜感激。

import Tkinter as tk

class SampleApp(tk.Tk):
    '''Illustrate how to drag items on a Tkinter canvas'''

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)

        # create a canvas
        self.canvas = tk.Canvas(width=400, height=400)
        self.canvas.pack(fill="both", expand=True)

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

        # create a couple movable objects
        self._create_token((100, 100), "white")
        self._create_token((200, 100), "black")

        # add bindings for clicking, dragging and releasing over
        # any object with the "token" tag
        self.canvas.tag_bind("token", "<ButtonPress-1>", self.OnTokenButtonPress)
        self.canvas.tag_bind("token", "<ButtonRelease-1>", self.OnTokenButtonRelease)
        self.canvas.tag_bind("token", "<B1-Motion>", self.OnTokenMotion)

    def _create_token(self, coord, color):
        '''Create a token at the given coordinate in the given color'''
        (x,y) = coord
        self.canvas.create_oval(x-25, y-25, x+25, y+25, 
                                outline=color, fill=color, tags="token")

    def OnTokenButtonPress(self, event):
        '''Being 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

    def OnTokenButtonRelease(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

    def OnTokenMotion(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

if __name__ == "__main__":
    app = SampleApp()
    app.mainloop()

Answer 1

这是您要找的吗：

import tkinter as tk

class SampleApp(tk.Tk):
    '''Illustrate how to drag items on a Tkinter canvas'''

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)

        # create a canvas
        self.canvas = tk.Canvas(width=400, height=400, bg='red')
        self.canvas.pack(fill="both", expand=True)

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

        # create a couple movable objects
        self._create_token((100, 100), "white", "User")
        self._create_token((200, 100), "black", "Ryan")

        # add bindings for clicking, dragging and releasing over
        # any object with the "token" tag
        self.canvas.tag_bind("token", "<ButtonPress-1>", self.OnTokenButtonPress)
        self.canvas.tag_bind("token", "<ButtonRelease-1>", self.OnTokenButtonRelease)
        self.canvas.tag_bind("token", "<B1-Motion>", self.OnTokenMotion)

    def _create_token(self, coord, color, mytext):
        '''Create a token at the given coordinate in the given color'''
        (x,y) = coord
        self.canvas.create_text(x-25, y-25,  
                                fill=color, tags="token", text=mytext)

    def OnTokenButtonPress(self, event):
        '''Being 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

    def OnTokenButtonRelease(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

    def OnTokenMotion(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

if __name__ == "__main__":
    app = SampleApp()
    app.mainloop()

？

我改变了什么：
（编辑线：10、18、19、27、30 和 31）
-canvas 背景颜色从默认（白色）变为红色，以更好地识别其上的白色和黑色对象；
-self.canvas.create_oval 到 self.canvas.create_text 因为你想要字符串而不是椭圆；
-此外，删除了第二对坐标 (x+25, y+25)，因为 create_text 只需要 一对坐标（create_oval 需要 两个），然后删除outline=color 因为文本对象没有 outline 选项，所以 Tkinter 返回 unknown option 错误；
- 最后，在将其从create_oval 更改为create_text 之后，我必须将text 选项mytext 添加到_create_token 函数（def _create_token(self, coord, color, mytext):）及其实例（“User”和“Ryan”） ) 到可移动对象：
self._create_token((100, 100), "white", "User") self._create_token((200, 100), "black", "Ryan").