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我正在尝试使用 tkinter 按钮来显示使用 sqlalchemy 和 PIL 的 ERD 图。我已经设法通过将生成的图片保存到文件中然后重新打开该文件以显示在标签中来实现这一点。

有没有办法让图像显示而无需先保存？

import tkinter as tk
from sqlalchemy_schemadisplay import create_schema_graph
import urllib
from sqlalchemy import MetaData, create_engine
from PIL import Image, ImageTk 

root = tk.Tk()

def erd_gen(pr):
    global erd_img
    conn = create_engine("mssql+pyodbc:///?odbc_connect={}".format(pr))
    grph_data = MetaData(bind=conn)
    graph = create_schema_graph(metadata=grph_data, show_datatypes=False, show_indexes=False, rankdir='LR', concentrate=False)
    graph.write_png('dbschema.png') # write file to folder 
    erd_img = ImageTk.PhotoImage(Image.open("dbschema.png")) #open file from folder, would like to do this by just referring to 'graph' and not the saved file
    panel.configure(image = erd_img)
    conn.close()


params = urllib.parse.quote_plus("DRIVER={SQL Server Native Client 11.0};"
                                    "SERVER=(localdb)\ProjectsV13;"
                                    "DATABASE=Test;"
                                    "Trusted_Connection=yes")  

tk.Button(root, text='Generate', command=lambda: erd_gen(params)).pack()

panel = tk.Label(root)
panel.pack()

root.mainloop()
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2 回答 2

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您可以使用 将其保存到类似文件的对象中io，请参见示例：

from tkinter import *
from PIL import Image, ImageTk
import urllib.request
import io

root = Tk()

show = Label(root)
show.pack()

img_url = 'http://hem.bredband.net/b235373/kroppkakor/DSCF0002.JPG'

with urllib.request.urlopen(img_url) as url:
    temp_file = io.BytesIO(url.read())

img = Image.open(temp_file)
tkimg = ImageTk.PhotoImage(image=img)
show.config(image=tkimg)

root.mainloop()
于 2020-05-04T12:02:12.580 回答
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您可以使用create_png()而不是write_png()创建PNG图像数据缓冲区，然后用于io.BytesIO模拟文件输入流：

from io import BytesIO

def erd_gen(pr):
    global erd_img
    conn = create_engine("mssql+pyodbc:///?odbc_connect={}".format(pr))
    grph_data = MetaData(bind=conn)
    graph = create_schema_graph(metadata=grph_data, show_datatypes=False, show_indexes=False, rankdir='LR', concentrate=False)
    iostream = BytesIO(graph.create_png())
    erd_img = ImageTk.PhotoImage(file=iostream)
    panel.configure(image=erd_img)
    conn.dispose()
于 2020-05-04T15:27:22.787 回答