State not updating in dialog box when using providers - flutter

Question

I am trying to open a dialog box to let users add 2 things:
1- Video thumbnail(Image file)
Video URL(String)
The user taps on an Inkwell which opens the dialog box, then the user clicks the inkwell in the dialog box to pick a video thumbnail i.e image file. The image file gets set, but it doesn't update the state of the inkwell which needs to show the picked file. The state is updated after hot reload. I am using the provider to set the image file and using its instance to check if the file is picked or not.
Change Notifier ->
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
class GetThumbnailImage extends ChangeNotifier {
PickedFile? image;
Future setImage(var file) async {
image = file;
notifyListeners();
}
}
Widgets using the change notifier ->
InkWell(
onTap: () {
getVideoImage().then((image) {
print(image);
if (image != null) {
_imageInstance.setImage(image);
}
});
},
child: SizedBox(
width: MediaQuery.of(context).size.width * 0.8,
height: MediaQuery.of(context).size.height * 0.25,
child: Center(
child: _imageInstance.image == null
? SizedBox(
width: 200,
height: 200,
child: FadeInImage(
image: NetworkImage(
apiBase + productId.toString() + apiLaterPart),
placeholder:
AssetImage("assets/images/Otherimages/addvideo.jpg"),
imageErrorBuilder: (context, error, stackTrace) {
return Image.asset(
'assets/images/Otherimages/addvideo.jpg',
fit: BoxFit.fitWidth);
},
fit: BoxFit.fitWidth,
),
)
: Image.file(
File(_imageInstance.image!.path),
),
),
))

Answer 1

Add a consumer widget on top of widgets that you want to rebuild
Center(
child: Consumer<GetThumbnailImage>(
builder:(context, model, child) => model.image == null
? SizedBox(
width: 200,
height: 200,
child: FadeInImage(
image: NetworkImage(apiBase +
productId.toString() +
apiLaterPart),
placeholder: AssetImage(
"assets/images/Otherimages/addvideo.jpg"),
imageErrorBuilder:
(context, error, stackTrace) {
return Image.asset(
'assets/images/Otherimages/addvideo.jpg',
fit: BoxFit.fitWidth);
},
fit: BoxFit.fitWidth,
),
)
: Image.file(
File(model.image!.path),
),
),
),

Answer 2

made this changes to your code and try
class GetThumbnailImage extends ChangeNotifier {
PickedFile? _image;
PickedFile get image => _image;
Future setImage(var file) async {
_image = file;
notifyListeners();
}
}

Answer 3

The reason is "dialog is not part of the widget tree"
Your code is not complete to help but here are some suggestions.
Solution 1.
You can pass the context of the parent widget to the dialog box, So the dialog box should also behave like a part of the widget tree
Solution 2. (Better)
Use something like this in the showDialogBox method...
final image = context.watch<GetThumbnailImage>();
ChangeNotifierProvider.value(
value: image
child: Dialog(...)
);
Now you can use instance of provider in the dialog box and it will also rebuild the widget tree to update the UI