python - 是否可以将 Canvas 作为按钮的图标？

Question

我在 Tkinter Canvas 上绘制了漂亮的多边形。我想把它作为 Tkinter 按钮的图标。

我在 this 中看到如何在 Canvas 上放置一个按钮，但这会覆盖多边形。当然，如果我将多边形放在按钮上，则该按钮将无法访问。

我试图避免使用外部图像。我希望保持代码独立，而不依赖于图像的路径。如果我们移动代码，事情就会崩溃。

from Tkinter import *

class Example(Frame):
    def __init__(self, master=None):
        Frame.__init__(self, master)
        self.widget()

    def Xshape (self,canvas,x,y,p,t,outline='black',fill='green',width=1):

        points =  []
        s = t - p
        for i in (1,-1):
            points.extend(( x,         y + (i*p) ))
            points.extend(( x + (i*s), y + (i*t) ))
            points.extend(( x + (i*t), y + (i*s) ))
            points.extend(( x + (i*p), y))
            points.extend(( x + (i*t), y - (i*s)  ))
            points.extend(( x + (i*s), y - (i*t)  ))

        canvas.create_polygon(points,outline=outline,
                              fill=fill,width=width)

    def widget(self):

        cWidth=64.
        cHeight=64.
        self.canv = Canvas(frame,width=cWidth,height=cHeight)
        self.Xshape(self.canv, (cWidth+2)/2,(cHeight+2)/2, cHeight/5,cHeight/2)
        self.toggle = Button(frame,relief=FLAT,text='test')
        self.win = self.canv.create_window(cWidth/2,cHeight/2,anchor=CENTER,window=self.toggle)  
        self.canv.grid(row=0,column=2)


root = Tk()
root.geometry('100x100+10+50')
root.wm_title("Telescope Health Status")
root.grid_rowconfigure( 1, weight=1)
root.grid_columnconfigure( 0, weight=1)

frame = Frame(root,bg='light blue',padx=30)
frame.grid(row=0, column=0, columnspan=20, sticky='ew')

app = Example(root)
app.mainloop()

这只会在多边形上放置一个按钮。我想将多边形放在按钮内。

Answer 1

您可以通过使用 Enter、Leave 和鼠标事件上的绑定(bind)来使 Canvas 本身模拟按钮的行为，而不是将 Canvas 放入按钮中:

• Canvas 浮雕设置为“凸起”，边框宽度为 1，使其看起来像一个按钮

• 当光标进入Canvas时背景颜色变为浅灰色

• 当按下鼠标按钮 1 时，浮雕设置为“凹陷”

• 当释放按钮 1 时，将执行参数中给出的命令，但前提是光标仍位于 Canvas 上并且浮雕恢复为“凸起”

• 当光标离开 Canvas 时，浮雕将恢复为“凸起”，并且恢复正常背景颜色

  from Tkinter import *
  
  class ButtonCanvas(Canvas):
      def __init__(self, master=None, command=lambda: None, **kw):
          Canvas.__init__(self, master, relief="raised", bd=1, **kw)
          self._bg = self.cget("bg")
          cWidth = 64
          cHeight = 64
          self.configure(width=64, height=64)
          self.Xshape((cWidth+2)/2,(cHeight+2)/2, cHeight/5,cHeight/2)
          self.command = command
  
          self.bind("<Enter>", self.on_enter)
          self.bind("<Leave>", self.on_leave)
          self.bind("<ButtonPress-1>", self.on_b1press)
          self.bind("<ButtonRelease-1>", self.on_b1release)
  
      def on_enter(self, event):
          self.configure(background="#ececec")
  
      def on_leave(self, event):
          self.configure(background=self._bg)
          self.configure(relief="raised")
  
      def on_b1press(self, event):
          self.configure(relief="sunken")
  
      def on_b1release(self, event):
          self.configure(relief="raised")
          if self.winfo_containing(event.x_root, event.y_root) == self:
              self.command()
  
      def Xshape (self,x,y,p,t,outline='black',fill='green',width=1):
  
          points =  []
          s = t - p
          for i in (1,-1):
              points.extend(( x,         y + (i*p) ))
              points.extend(( x + (i*s), y + (i*t) ))
              points.extend(( x + (i*t), y + (i*s) ))
              points.extend(( x + (i*p), y))
              points.extend(( x + (i*t), y - (i*s)  ))
              points.extend(( x + (i*s), y - (i*t)  ))
  
          self.create_polygon(points,outline=outline,
                              fill=fill,width=width)
  
  
  root = Tk()
  
  def cmd():
      print("ok")
  
  ButtonCanvas(root, command=cmd).pack()
  Button(root, command=cmd).pack()
  
  root.mainloop()