我从引用的问题中修改了代码。现在，当鼠标在画布上拖动时，它显示矩形。画布显示Lena图像。
import tkinter as tk # this is in python 3.4. For python 2.x import Tkinterfrom PIL import Image, ImageTkclass ExampleApp(tk.Tk): def __init__(self): tk.Tk.__init__(self) self.x = self.y = 0 self.canvas = tk.Canvas(self, width=512, height=512, cursor="cross") self.canvas.pack(side="top", fill="both", expand=True) self.canvas.bind("<ButtonPress-1>", self.on_button_press) self.canvas.bind("<B1-Motion>", self.on_move_press) self.canvas.bind("<ButtonRelease-1>", self.on_button_release) self.rect = None self.start_x = None self.start_y = None self._draw_image() def _draw_image(self): self.im = Image.open('./resource/lena.jpg') self.tk_im = ImageTk.PhotoImage(self.im) self.canvas.create_image(0,0,anchor="nw",image=self.tk_im) def on_button_press(self, event): # save mouse drag start position self.start_x = event.x self.start_y = event.y # create rectangle if not yet exist #if not self.rect: self.rect = self.canvas.create_rectangle(self.x, self.y, 1, 1, fill="black") def on_move_press(self, event): curX, curY = (event.x, event.y) # expand rectangle as you drag the mouse self.canvas.coords(self.rect, self.start_x, self.start_y, curX, curY) def on_button_release(self, event): passif __name__ == "__main__": app = ExampleApp() app.mainloop()黑色正方形绘制在图像顶部。希望这可以帮助。
