I'm trying to follow data-binding example from official google doc https://developer.android.com/tools/data-binding/guide.html
except that I'm trying to apply data-biding to a fragment, not an activity.
the error I'm currently getting when compiling is
Error:(37, 27) No resource type specified (at 'text' with value '@{marsdata.martianSols}.
onCreate
for fragment looks like this:
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
MartianDataBinding binding = MartianDataBinding.inflate(getActivity().getLayoutInflater());
binding.setMarsdata(this);
}
onCreateView
for fragment looks like this:
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.martian_data, container, false);
}
and parts of my layout file for fragment looks like this:
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<data>
<variable
name="marsdata"
type="uk.co.darkruby.app.myapp.MarsDataProvider" />
</data>
...
<TextView
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="@{marsdata.martianSols}"
/>
</RelativeLayout>
</layout>
my suspicion is that MartianDataBinding
doesn't know which layout file it's supposed to be bound with - hence the error. Any suggestions?
The data binding implementation must be in the onCreateView
method of the fragment, delete any data Binding that exist in your OnCreate
method,
your onCreateView
should look like this:
public View onCreateView(LayoutInflater inflater,
@Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
MartianDataBinding binding = DataBindingUtil.inflate(
inflater, R.layout.martian_data, container, false);
View view = binding.getRoot();
//here data must be an instance of the class MarsDataProvider
binding.setMarsdata(data);
return view;
}
Smart way to bind the fragment View using abastract
generics
classes : BindingFragment.kt
abstract class BindingFragment<T : ViewBinding> : Fragment() {
protected lateinit var binding: T
abstract fun getViewBinding(): T
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
binding = getViewBinding()
return binding.root
}
}
override the function in your Fragment class
:
class YourFragment: BindingFragment<YourFragmentFragBinding>(){
override fun getViewBinding() = YourFragmentFragBinding.inflate(layoutInflater)
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
// write here your view logics
}
}