修改代码以拖动字符串

Question

我一直在试图理解我从Bryan Oakley here遇到的代码。目前，该代码允许用户使用tkinter拖动两个椭圆。我希望能够修改此代码，以便用户不用椭圆就可以从两个列表中拖动字符串（键值对）并匹配它们。例如，我希望用户能够从一个列表中拖拽一个字符串，如“User”，并从另一个列表中拖拽“Ryan”并匹配它们。我将不胜感激任何关于如何修改代码的输入，以便用户能够拖动这两个字符串。

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

这是你在找什么：

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() 

？

我改变什么：
（EDITED LINES：10，18，19，27，30和31）从默认（白色）
-canvas背景颜色为红色，以确定在其上更好的白色和黑色的物体;
- self.canvas.create_oval到self.canvas.create_text因为你想要字符串而不是椭圆形;
- 同样，取出第二对坐标（x+25, y+25）因为create_text需要只有一对夫妇坐标（​​对他们的要求），并删除outline=color因为文本对象没有outline选项，因此Tkinter的返回一个unknown option错误;
-and最后，从​​将其更改为create_text后，我不得不把text选项mytext添加到_create_token功能（def _create_token(self, coord, color, mytext):）及其实例（“用户” &“瑞安”）到可移动的物体：
self._create_token((100, 100), "white", "User") self._create_token((200, 100), "black", "Ryan")。