更新时间:2023-01-06 18:15:41
io.BytesIO()
执行后,data
为Bytes.使用 Kivy
REQUIREMENT
I'm trying to retrieve an image from Database and set this image to kivy image widget, this operation throws a ValueError, unsure of the cause. Welcome any inputs.
Database: Sqlite3
Table name: Users
Columns: UserID, UserName, UserImage
def populate_fields(self): # NEW
# Code retrieves text data and display in textinput fields here.
# STEP 1: RETRIEVE IMAGE
connection = sqlite3.connect("demo.db")
with connection:
cursor = connection.cursor()
cursor.execute("SELECT UserImage from Users where
UserID=?",self.data_items[columns[0]]['text'] )
image = cursor.fetchone()
data = io.BytesIO(image[0])
#STEP 2: SET OUTPUT TO IMAGE WIDGET
self.image.source = data # ---> triggers an Error
ERROR TRACEBACK:
self.image.source = data
File "kivyweakproxy.pyx", line 33, in kivy.weakproxy.WeakProxy.__setattr__ (kivyweakproxy.c:1471)
File "kivyproperties.pyx", line 478, in kivy.properties.Property.__set__ (kivyproperties.c:5572)
File "kivyproperties.pyx", line 513, in kivy.properties.Property.set (kivyproperties.c:6352)
File "kivyproperties.pyx", line 504, in kivy.properties.Property.set (kivyproperties.c:6173)
File "kivyproperties.pyx", line 676, in kivy.properties.StringProperty.check (kivyproperties.c:8613)
ValueError: Image.source accept only str
After execution of io.BytesIO()
, data
is in Bytes. Use Kivy CoreImage and texture
to convert data
.
Replace
self.image.source = data
with:
self.image.texture = CoreImage(data, ext="png").texture
source
Filename / source of your image.
source is a StringProperty and defaults to None