Question

由于这种情况，我试图将大多数代码打包到我称为ImgFromUrl()

的函数中

import io
import tkinter as tk
import urllib.request
from PIL import Image, ImageTk

def ImgFromUrl(root, url):
    with urllib.request.urlopen(url) as connection:
        raw_data = connection.read()
    im = Image.open(io.BytesIO(raw_data))
    image = ImageTk.PhotoImage(im)
    return tk.Label(root, image=image)

root = tk.Tk()
url = "http://imgs.xkcd.com/comics/python.png"

widget = ImgFromUrl(root,url)
widget.grid(row=0,column=0)

root.mainloop()

由于某种原因，图像没有显示出来（尽管Tkinter窗口已自动调整为图像的大小）。

但是，这有效：

# same imports

root = tk.Tk()
url = "http://imgs.xkcd.com/comics/python.png"

with urllib.request.urlopen(url) as connection:
    raw_data = connection.read()
im = Image.open(io.BytesIO(raw_data))
image = ImageTk.PhotoImage(im)

widget = tk.Label(root, image=image)
widget.grid(row=0,column=0)

root.mainloop()

Answer 1

所以您的问题是，image一旦函数结束就被删除了，并且tkinter需要将图像保存在某个地方以供参考。

我们可以使用global或通过将图像返回到全局变量中来实现。

选项1 global：

import tkinter as tk
import urllib.request
from PIL import Image, ImageTk
import io


def ImgFromUrl(url):
    global image
    with urllib.request.urlopen(url) as connection:
        raw_data = connection.read()
    im = Image.open(io.BytesIO(raw_data))
    image = ImageTk.PhotoImage(im)
    return image

root = tk.Tk()
url = "http://imgs.xkcd.com/comics/python.png"
widget = tk.Label(root, image=ImgFromUrl(url))
widget.grid(row=0, column=0)

root.mainloop()

选项2将图像对象返回到在全局命名空间中定义的变量：

import tkinter as tk
import urllib.request
from PIL import Image, ImageTk
import io


def ImgFromUrl(url):
    with urllib.request.urlopen(url) as connection:
        raw_data = connection.read()
    im = Image.open(io.BytesIO(raw_data))
    image = ImageTk.PhotoImage(im)
    return image

root = tk.Tk()
url = "http://imgs.xkcd.com/comics/python.png"
image = ImgFromUrl(url)
widget = tk.Label(root, image=image)
widget.grid(row=0, column=0)

root.mainloop()

Python 3的tkinter |来自网址的图片未显示

1 个答案: