用Tkinter正確地實例化課程

Question

我的目標是每次用戶按下shift按鈕時加載一個新的「箭頭」圖像。我想，我可以爲箭頭創建一個類，以便爲每個實例創建一個新的實例，其中每個實例都有自己的座標，等等。但顯然我做錯了。我試圖爲實例創建一個列表，以便我可以迭代它，然後在每個實例中使用moveArrow方法。我剛剛獲得了5個參賽項目，因爲我想要限制5個箭頭。我希望這段代碼不會給你眼睛或類似的東西：P我是一個新手，我很抱歉，如果代碼非常糟糕或者如何處理我的問題的方法。謝謝你的幫助:)

#!/usr/bin/python 

from Tkinter import * 
from PIL import ImageTk, Image 


class frameApp(Frame): 
     def __init__(self, master=None): 
       Frame.__init__(self, master, height = 400, width = 400) 
       self.charImg = ImageTk.PhotoImage(Image.open("Archer.gif")) 
       self.arrowImage = ImageTk.PhotoImage(Image.open("arrow.gif")) 
       self.charLabel = Label(self, image = self.charImg) #Loading character label 
       self.charLabel.pack() 
       self.arrow = Label(self, image = self.arrowImage) 
       self.arrow.pack() 
       self.shift = False 
       self.down = False 
       self.right = False 
       self.left = False 
       self.up = False 
       self.x_coord = 200 
       self.y_coord = 200 
       self.pack_propagate(0) 
       self.pack() 
       self.arrowList = ["Inst1", "Inst2", "Inst3", "Inst4", "Inst5"] 
       self.counter = -1 
     def moveableImage(self): 
       self.charLabel.place(y=self.y_coord, x=self.x_coord) 
     def createArrow(self): 
       self.arrowList[counter] = arrow() 
     def moveArrow(self): 
       for arrowList in self.arrowList: 
         arrowList.moveArrow 

     def keyPressed(self, event): 
       if event.keysym == 'Down': 
         self.down = True 
       elif event.keysym == 'Right': 
         self.right = True 
       elif event.keysym == 'Left': 
         self.left = True 
       elif event.keysym == 'Up': 
         self.up = True 
       elif event.keysym == 'Shift_L': 
         self.shift = True 
     def keyReleased(self, event): 
       if event.keysym == 'Down': 
         self.down = False 
       elif event.keysym == 'Right': 
         self.right = False 
       elif event.keysym == 'Left': 
         self.left = False 
       elif event.keysym == 'Up': 
         self.up = False 
       elif event.keysym == 'Shift_L': 
         self.shift = False 
     def task(self): 
       if self.down and self.y_coord < 360: 
         self.y_coord = self.y_coord + 10 
       elif self.right and self.x_coord < 370: 
         self.x_coord = self.x_coord + 10 
       elif self.left and self.x_coord > 10: 
         self.x_coord = self.x_coord - 10 
       elif self.up and self.y_coord > 10: 
         self.y_coord = self.y_coord - 10 
       elif self.shift: 
         self.counter += 1 
         self.createArrow() 
       root.after(20,self.task) 
       root.after(20,self.moveArrow) 
       self.moveableImage() 

class arrow(object): 
     def __init__(self): 
       self.x_coordArrow = app.x_coord 
       self.y_coordArrow = app.y_coord 
     def moveArrow(self): 
       self.x_coordArrow = self.x_coordArrow + 20 

root = Tk() 
root.title("Frametitel") 
app = frameApp(master=root) 
root.bind_all('<Key>', app.keyPressed) 
root.bind_all('<KeyRelease>', app.keyReleased) 
root.after(20, app.task) 
app.mainloop() 

Answer 1

你有幾個選擇來處理這個問題。創建一個新的類來調用arrow()的多個實例可能是最好的選擇。

我會爲應用程序窗口創建一個類，但您應該在Arrow類中刪除所有不必要的東西。然後，使Arrow類成爲Tkinter小部件的子類，如Frame，並讓它處理它的方法。

下面是這是一個非常簡化的版本：

from Tkinter import * 
from random import randint 

class App(Frame): 
    def __init__(self, master=None): 
     Frame.__init__(self, master, height=400, width=400) 
     self.master = master 
     self.master.bind('<Shift_L>', self.createArrow) 

    def createArrow(self, event): 
     #this is the only arrow method in this class. It waits for the Shift event, 
     #then makes a new instance of Arrow and calls Arrow's method to get it moving 
     self.arrow = Arrow(self) 
     self.arrow.moveArrow(self.arrow, randint(0,400), randint(0,400)) 

class Arrow(Frame): 
    def __init__(self, master): 
     Frame.__init__(self, master) #This makes the frame, 
     Label(self, text='===>').pack() #and puts a Label (the graphic) inside it 

    def moveArrow(self, arrow, xCoord, yCoord): 
     #the move arrow method - arguments are the arrow instance and the x,y coords 
     arrow.place_forget()   #un-place the instance 
     arrow.place(x=xCoord, y=yCoord) #replace with new x,y 
     self.after(500, lambda: self.moveArrow(arrow, xCoord+1, yCoord)) #repeat, changing x 

root = Tk() 
app = App(root).pack() 
root.mainloop()