使用监听器绑定的android数据绑定错误

Question

我将视图模型中的侦听器绑定到片段 xml 中 FAB 的单击。

我的片段 xml 显示了 FAB。

 <data>
        <variable
            name="vehicleViewModel"
            type="com.buildit4me.autonance.ui.VehicleViewModel" />
        <variable
            name="launcher"
            type="androidx.activity.result.ActivityResultLauncher" />

 <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/fabVehicles"
        android:contentDescription="@string/fab_content_description"
        style="@style/FAB"
        android:onClick="@{(view) -> vehicleViewModel.FabOnClick(view,launcher)}"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

我的 Viewmodel 监听器

  public void FabOnClick( View view,  ActivityResultLauncher<Intent> launcher){
         Intent intent= new Intent(view.getContext(), AddNewEntityActivity.class);
         intent.putExtra(getApplication().getResources().getString(R.string.fragmentID), R.layout.fragment_add_vehicle);
         launcher.launch(intent);
     }

在我的片段中

 ActivityResultLauncher<Intent> launcher= registerForActivityResult(new ActivityResultContracts.StartActivityForResult(), new ActivityResultCallback<>() {
        @Override
        public void onActivityResult(ActivityResult result) {
              if(result.getResultCode()== Activity.RESULT_OK){
                  mVehicleViewModel.getAllVehicles();
              }
             String msg;
              try {
                   msg =  result.getData().getStringExtra(getResources().getString(R.string.intent_msg));
              }
              catch( NullPointerException e){
                  msg=null;
              }
            Utils.displaySnackbar(binding.recyclerviewVehicles,binding.fabVehicles,msg);
        }
    });

public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        binding= DataBindingUtil.inflate(inflater,R.layout.fragment_vehicles,container,false);        
        mVehicleViewModel = new ViewModelProvider(requireActivity()).get(VehicleViewModel.class);
        binding.setVehicleViewModel(mVehicleViewModel);
        binding.setLauncher(launcher);

我构建项目时的错误。

[databinding] {"msg":"cannot find method FabOnClick(android.view.View, androidx.activity.result.ActivityResultLauncher) in class com.buildit4me.autonance.ui.VehicleViewModel","file":"app/src/main/res/layout/fragment_vehicles.xml","pos":[{"line0":30,"col0":37,"line1":30,"col1":78}]}

我尝试使缓存失效以清除生成的绑定文件，但仍然收到错误。

Answer 1

我认为问题的原因在于XML（androidx.activity.result.ActivityResultLauncher）和Fragment（ActivityResultLauncher

）中的

launcher类型之间的差异。

您可以尝试替代解决方案。不绑定ActivityResultLauncher，使用该实例内部片段。

<com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/fabVehicles"
        android:contentDescription="@string/fab_content_description"
        style="@style/FAB"
        android:onClick="@{(view) -> vehicleViewModel::FabOnClick}"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

片段中

  public void FabOnClick(){
         Intent intent= new Intent(getContext(), AddNewEntityActivity.class); // Can use context of fragment
         intent.putExtra(getApplication().getResources().getString(R.string.fragmentID), R.layout.fragment_add_vehicle);
         launcher.launch(intent);
     }

希望有帮助