使背景图片适应画布大小import time from tkinter import * import turtle # 导入turtle模块 import time class ShowWelcome(Frame): def __init__(self, master=None): Frame.__init__(self, master) self.root = master # 定义内部变量root self.createPage() def createPage(self): canva = Canvas(self.root, width=500, height=500) # 设定画布 canva.pack() theScreen = turtle.TurtleScreen(canva) # 设定turtle屏幕 path = turtle.RawTurtle(theScreen) # 设定画笔 # 添加背景 bg_image = PhotoImage(file="background.png") canva.create_image(0, 0, anchor=NW, image=bg_image) path.color('#87CEFA') # 设定画笔颜色 path.left(180) path.up() # 抬笔 path.forward(80) path.down() # 落笔 path.write('欢迎进入本系统', font=('宋体', 18)) path.up() path.forward(100) path.down() path.left(90) path.forward(100) path.left(90) path.forward(350) time.sleep(3) canva.pack_forget()

要使背景图片适应画布大小，可以使用`canva.create_image()`方法时设置`width`和`height`参数为画布的宽度和高度。以下是修改后的代码：

import time
from tkinter import *
import turtle  # 导入turtle模块
import time

class ShowWelcome(Frame):
    def __init__(self, master=None):
        Frame.__init__(self, master)
        self.root = master  # 定义内部变量root
        self.createPage()

    def createPage(self):
        canva = Canvas(self.root, width=500, height=500)  # 设定画布
        canva.pack()

        theScreen = turtle.TurtleScreen(canva)  # 设定turtle屏幕
        path = turtle.RawTurtle(theScreen)  # 设定画笔

        # 添加背景
        bg_image = PhotoImage(file="background.png")
        canva.create_image(0, 0, anchor=NW, image=bg_image, width=500, height=500)

        path.color('#87CEFA')  # 设定画笔颜色
        path.left(180)
        path.up()  # 抬笔
        path.forward(80)
        path.down()  # 落笔
        path.write('欢迎进入本系统', font=('宋体', 18))
        path.up()
        path.forward(100)
        path.down()
        path.left(90)
        path.forward(100)
        path.left(90)
        path.forward(350)
        time.sleep(3)
        canva.pack_forget()

在`canva.create_image()`方法中添加了`width=500`和`height=500`参数来适应画布的大小。请确保将`width`和`height`参数的值替换为你的画布实际的宽度和高度。