title: how to convert image url to asset in flutter?
body: <p>i used multi_image_picker package to get images from gallery.now i want to implement edit page and i need to convert my images url list to asset and set the asset list to multi_image_picker.
  here is my multi image picker:</p>
  <pre><code>List&lt;Asset&gt; resultList = &lt;Asset&gt;[];
  String error = 'No Error Detected';
  
  try {
    resultList = await MultiImagePicker.pickImages(
      maxImages: 300,
      enableCamera: true,
      selectedAssets: _imagesAssets,
      cupertinoOptions: CupertinoOptions(takePhotoIcon: &quot;chat&quot;),
      materialOptions: MaterialOptions(
        actionBarColor: &quot;#abcdef&quot;,
        actionBarTitle: &quot;صندوق شهدای موردک&quot;,
        allViewTitle: &quot;تمام تصاویر&quot;,
        useDetailsView: false,
        selectCircleStrokeColor: &quot;#000000&quot;,
      ),
    );
  } on Exception catch (e) {
    error = e.toString();
  }
  
  // If the widget was removed from the tree while the asynchronous platform
  // message was in flight, we want to discard the reply rather than calling
  // setState to update our non-existent appearance.
  if (!mounted) return;
  
  setState(() {
    _imagesAssets = resultList;
  });
  </code></pre>
  <p>}</p>
  <p>and a grid view to show the selected images:</p>
  <pre><code> return GridView.count(
    crossAxisCount: 2,
    shrinkWrap: true,
    physics: NeverScrollableScrollPhysics(),
    padding: EdgeInsets.all(10),
    children: List.generate(_imagesAssets.length, (index) {
      Asset asset = _imagesAssets[index];
      return AssetThumb(
        asset: asset,
        width: 100,
        height: 100,
      );
    }),
  );
  </code></pre>