如何更新画布上的图像？

HansFritz 发表于 Dev

汉斯·弗里兹

这是我遇到麻烦的代码的本质：

camelot = Canvas(main, width = 400, height = 300)
camelot.grid(row = 0, column = 0, rowspan = 11, columnspan = 3)
MyImage = PhotoImage(file = "sample1.gif")
camelot.create_image(0, 0, anchor = NW, image = MyImage)

这是从一开始就运行的。我以后想要在另一个函数中执行的操作是替换"sample1.gif"为"sample2.gif"，并且可能以后再替换为"sample3.gif"。我被困住了，到目前为止，我一直没有尝试过的任何方法。

简单

将图像添加到画布：

self.image_on_canvas = self.canvas.create_image(0, 0, image = ...)

更改图片：

self.canvas.itemconfig(self.image_on_canvas, image = ...)

完整示例：

from Tkinter import *

#----------------------------------------------------------------------

class MainWindow():

    #----------------

    def __init__(self, main):

        # canvas for image
        self.canvas = Canvas(main, width=60, height=60)
        self.canvas.grid(row=0, column=0)

        # images
        self.my_images = []
        self.my_images.append(PhotoImage(file = "ball1.gif"))
        self.my_images.append(PhotoImage(file = "ball2.gif"))
        self.my_images.append(PhotoImage(file = "ball3.gif"))
        self.my_image_number = 0

        # set first image on canvas
        self.image_on_canvas = self.canvas.create_image(0, 0, anchor = NW, image = self.my_images[self.my_image_number])

        # button to change image
        self.button = Button(main, text="Change", command=self.onButton)
        self.button.grid(row=1, column=0)

    #----------------

    def onButton(self):

        # next image
        self.my_image_number += 1

        # return to first image
        if self.my_image_number == len(self.my_images):
            self.my_image_number = 0

        # change image
        self.canvas.itemconfig(self.image_on_canvas, image = self.my_images[self.my_image_number])

#----------------------------------------------------------------------

root = Tk()
MainWindow(root)
root.mainloop()