Changed to use "Request" to download files.

Added a example image.

README.md

@@ -2,6 +2,8 @@
 
 Anvil extension that downloads an image and sets it as the background.
 
+![Example](example.webp)
+
 ----
 
 
@@ -13,7 +15,7 @@ pipx install git+https://moli-git.zapto.org/moli/aecpic.git
 
 # Run
 
-on inside Anvil.
+On inside Anvil.
 
 ```
 aecpic https://moli-green.xyz/img.webp

src/aecpic/__init__.py

@@ -1,10 +1,9 @@
 '''
-get a picture at some url in use curl, then open new anvil window and set the picture to background picture on to the window.
+It download an image useing HTTP or HTTPS protocol, Download the image file from URL, and set it as background of Anvil Editor window.
 '''
 
 import sys
 import os
-import subprocess
 import tempfile
 import json
 import click
@@ -45,18 +44,21 @@ def download(url):
     >>> assert r != ''
     '''
 
-    cr = subprocess.run(['curl', url], capture_output = True)
+    r = requests.get(url)
-    if cr.returncode != 0:
+    suffix = getSuffix(r.content)
-        raise RuntimeError('Downlad failed.')
+
+    #cr = subprocess.run(['curl', url], capture_output = True)
+    #if cr.returncode != 0:
+    #    raise RuntimeError('Downlad failed.')
+    #
+    #suffix = getSuffix(cr.stdout)
 
-    suffix = getSuffix(cr.stdout)
     filename = None
-
     with tempfile.NamedTemporaryFile(
             mode='wb',
             delete=False,
             suffix=suffix) as f:
-        f.write(cr.stdout)
+        f.write(r.content)
         filename = f.name
     return filename